What are the advantages/disadvantages of each? Also what are the similarities & differences between two calibers?

One is faster, one is bigger. Matter of preference.

The 10mm has the same energy at 100 yards as the .45 does at the muzzle. It's very similar (but not identical) to the .41 magnum. It's one hell of a versatile cartridge, especially if you're a reloader.

If you want just one self-defense pistol, then probably the .45 is a better choice - wider selection of guns, and it's easy to find ammo. With good ammo, and good shooting, they are effective defensive weapons. The 10mm is a pistol loony's caliber (to paraphrase John Barsness )

It's pretty easy to get 1300 fps out of a 10mm, with 155 gr bullets, which is as good or better than current .357 magnum loads. The .41 mag will drive heavier bullets the same speed, but no one makes a semi-auto .41 - at least not in wide circulation.

In a standard 1911, you can get nine shot CMC mags, and so you've basically got a 10 shot 1911, which is far from a bad thing. Of course if you Glock, you can have even more in the mag.

It's a fun cartridge, easy to load. The parent case is the basis for the .40 S&W, the .357 Sig, and the 9x25, so if you like to change calibers you could theoretically just change barrels and maybe the magazine, to change calibers. I have a Colt with extra .40 cal barrel; one of these days I oughta fit barrels for the other two calibers to it

The downsides are ammo availability, and also limited selection of guns. If you don't fancy Glocks or 1911's, you may have to look for one of the discontinued S&W's (edit to add - I guess the EAA Witness is also available in it). Ruger made a few combo Blackhawks in .38/40 and 10mm combo, while S&W made the 610 revolver on the N frame. If I ever find one of them in the rare 5" barrel I might have to get one

you made me look up one of my reloads.
a 200grain xtp through a ruger buckeye shooters conversion 38.40/10mm, in the ten mill it clocked through a chrony the following:
1.1318
2.1302
3.1303
4.1290
5.1301
6.1295
out of a kkm barreled glock i am getting a little over 1200 out of the above, and with a six inch around 1285fps.
i would say that kicks a .45acp butt, and i like .45acp.
and as kevin says at distance you have a much flatter flight.

I have both, and both have their advantages over one another. I prefer the 45 at home, and if I'm on the trail in the backwoods, I want the 10 on my hip. Ammo is much more plentiful and cheaper for the 45, but if you reload, the 10 is fairly cheap to shoot. They are both similar in recoil.
There are many more companies loading for the 10 than there were 20 years ago when I bought my first one. Hornady, Cor-Bon, Double Tap, Winchester, Buffalo Bore, Federal all produce ammo for the 10. It's becoming much more common. I can think of 8 or 9 companies making 10MM auto loaders. The 10 runs at much higher pressures than the 45. It's really lucky for us 10MM nuts that the 40 S&W caught on because there is a wide variety of 40 caliber bullets to choose from.

The downside of the 10mm? Nearly twice the peak pressure of the .45 ACP (37,500-psi vs. 21,000-psi), 40% more bolt thrust, and even 35% more than the .357 Mag.

All that zap means choice between larger, heavier handguns or a shorter service life. Barrels won't last as long regardless.

I'd just add that it comes close to the performance of the 41 Magnum but with alot less recoil and muzzle blast. Not a bad deal.
In the same gun, it kicks both harder and faster. Or at least it has in the 1911 guns I've played with.
A practical field load for big game. Lots of penetration with the heavier bullets, particularly the 200 gr. flat point stuff.
I really apreciate mine. Both my 1911 .45's and my 1006 Smith. They cover my needs a little differently.For instance, I prefer the .45 as a small gun pistol, while I prefer the 10mm as a bear gun. E

What do you want it to do?

CCW? I'd likely side with the .45ACP, for more than a few reasons.

Field? 10mm, again, for more than a few reasons.

FWIW, I have, and dote heavily on, both.

DING DING DING - we have a winner

Have to go with that advice. I keep both in full size 1911's and that's exactly how they are used. The 45 (along with a smaller 45) gets most of the range time and almost all of the carry time. The 10mm gets field use and carried when in conjunction with field use. Both are great rounds. Glad it doesn't have to be one or the other!

I have shot both cartridges in a range of Glocks including 20 + 29 and 21 + 30 and with a vareity of ammo both factory and handloads and in all cases, the 10mm's were notably more accurate and recoiled straight back into the hand.

I liked them very much and would not consider a .45 over a 10mm though, I would also own a .45.

John

Aussie that is very close to what I found in my tests of the Glocks in .45 & 10mm. I mostly carry the .45 in a shoulder rig when in a vehicle for up close situations. Outside the vehicle it is the 10mm that will get the call.......Penetration with the 10mm is deeper and more accurate by 1 inch at 35 feet.

I have Glock 20 10mm with a couple of barrels.
Compared to a 45acp, 10mm sucks.

The 45 has a stronger case head and can go higher pressure.
The 45 has more case volume and can go higher power.
The 45 has a bigger diameter and makes a bigger hole.

Both great rounds. Load appropriately and go forth with confidence!

How dat? The .45 has more case capacity. Unless you are talking some decrepit design vs. a modern one, the .45 trumps the 10. This is especially true if you reload. The 10 can be bought in pretty much maximum loads. Maybe the .45 can too. I'm not familiar enough with all .45 offerings to know. It certainly used to be the case that the .45 was pretty underloaded.

They're both great auto cartridges. The .45 just holds more.

10mm SAAMI Max Ave. Pressure 37,500
45 +P Auto SAAMI Max Ave. Pressure 23,000

Okay, if you really think the 10 is the stronger case, I stand corrected. I personally don't think it has an edge, but to each his own.

I don't know anything about the case, but the 45 being larger doesn't much matter if the pressure limit constrains you using all that extra space. But I don't imagine anyone is making 10mm cases that won't take the SAAMI limit. Maybe 45 cases are just waaay sturdier than they need to be?

I have shot 45acp brass at 50,000 psi and the primer pocket does not get loose and there is long brass life.

You can't do that with 10mm brass. It is the weakest brass around.

The only thing you got is the case and the gun strength wise. I already covered the platform issue in a post preceding both of ours. That leaves the case. If the case is just as strong as the 10 and the gun is as strong, then you basically have the same limits for pressure, no? Ifso, the .45's larger capacity always trumps the 10's lesser. That's what I was saying. I'm not a physicist though.

My thought is that the 10 is a lot like the .308 in that it has always been loaded near potential, whereas the 45 ACP has not. There is a lot more room for improvement with the ACP, or at least there was. There are some hot +P loads out there now.

Another thing is people always comparing the 10 to the 41 Mag. It ain't a 41. It ain't a 38-40. It's the 10, which is good enough, maybe better than you need for killing folks, since the .40 seems more than adequate. Probably not good enough for the real dangerous game though. But then, experience trumps speculation and I am not an experienced dangerous game hunter. Per my speculation, I would want something more than either for truly dangerous game, either protection or hunting. The 10 does have a lot of firepower, especially in the Glock and some others. I think...I KNOW I'd take a hot-loaded 38-40 over a 10 for dangerous game.

I may be wrong, but I seem to recall that back in the mid-70s when Whit Collins was further developing the .40G&A/10mm Police round it was based on a belted cartridge... perhaps a cut down...? I believe that the purpose of using a belted cartridge was two-fold: better head spacing and the ability to deal with higher pressures for increased performance.

Perhaps someone with a full run of GUNS & AMMO magazines can dig through the 1976/77 issues for a more definitive answer?

And, you were running that 50k PSI .45ACP brass in exactly, what, again?

I'm not a physicist, and I didn't stay at a Holiday Inn Express last night, but my guess is that they don't have the same limits for pressure. Pressure is per inches squared, and the 45 is pushing back on a greater area, so the same pressure equals more force, which is what's really beating on the gun. I'm not sure what you're saying about the gun, but if we're comparing the cartridges in identical guns, then I assume there is also going to be less margin (metal holding in the pressure) in the gun with a larger chamber. I certainly don't have a dog in this fight, I've never even had a 10mm.

My Guns better 'n ALL your guns!
So there!

ptthhhh

No and yes.

Generally the pressure limit is imposed by the handgun, not the case. In a semi-auto the limiting factor is slide force which is a function of slide mass and velocity. In a 1911 that's especially true. The .460 Rowland is a good example. It has the same case capacity of the .45 ACP but it runs at 40,000 psi. In a 1911 spring rate alone can't cut the slide velocity enough so it requires a compensator. In other designs a heavier recoil spring alone will do the job.



That's also correct. In the rifle world it's called "bolt thrust". At the same pressure a larger diameter bullet will exert more force on the handgun than a smaller diameter. Guys like to talk about the 'same pressure, more performance' in comparing the .45 Colt to the .44 Mag, but they rarely take bolt thrust into account. While it's true there is a certain amount of free lunch with the .45 Colt, bolt thrust narrows the gap.

which has more pressure on your carpet a 150 lb lady wearing high heels or oxfords, the high heels of course, the same pressure on on a smaller surface area has more force, the unit of force per unit of area.. the same reason a 38 super shooting major is worse than a 10mm , when reloading a 45 gives up nothing to a 10 mm. Have both shoot both.

You're calculating it backwards. The result (pressure) is already in pounds per square inch.

To use your analogy, you'd have to compare the high heels at 150-psi to the oxfords at 150-psi. By virtue of the greater surface area the oxfords would exert the greater total pressure.

same pressure over a smaller area doesn't change the pressure it's still applied over the smaller area. smaller area sees greater force.

My only recollection was Whit using .30 Rem brass and resizing bullets to .40 because .41 wouldn't fit, and that's how we ended up with a .40 instead of a .41 like the .41 AE. Not sure about the belted cases, he may have used them; I just don't remember anything about them.

You can type it out a hundred times, it's still back-asswards.

The units of pressure are lbs. (the force) divided by square inches.

If the pressure is the same, but the areas are different, the force must be exactly proportional to the difference in the areas.

In other words, same pressure, smaller area, yields smaller force, by definition.

It sounds like you are coming at this from both ends and meeting in the wrong place in the middle. What would be correct to say is that for the same force, the smaller cartridge would see a higher pressure.

I'm talking about factory loadings and SAAMI specs.

The first sentence is correct, but the second is contradictory. The total force exerted on one square inch at 150-psi is 150-lbs. The total force exerted on two square inches at 150-psi is 300-lbs.

The .45 ACP is perfect just the way it is. It was designed to be as low pressure as they could manage, because it�s a military cartridge and lower pressure is always preferred over higher pressure for military applications for a lot of reasons.

To create some hot-rod hunting rounds, yeah you could stuff more powder in there, but the .45 ACP was created as a combat round and nothing else; and for that purpose, it is damn near perfect.

Exactly.

As I recall early on (1970-71?) Whit started out with a cut down .38-40, and improved on it as he went along. Later (when I was at G&A) he was experimenting with other brass-- possibly custom stuff from NORMA. The last iteration I seem to remember was a belted case round that fired through a modified Browning Hi-Power.

I always felt the only advantage to the 10mm was increased accuracy at 50+ yards-- well beyond the 7-21 feet at which most shootouts occur. That being the case, I was never able to see any real-world, practical advantage that the 10mm pistol had over the .45 ACP.

From a defensive standpoint, correct?

Agreed,

What was really needed (and I believe time has proven this to be true) was bullet development of the .45 ACP (and 9mm) to give better than FMJ performance from auto pistols; essentially putting an auto pistols on equal footing with a revolver in the realm of terminal ballistics. Simply creating another auto pistol round that pushes the same bullet designs to a different velocity wasn�t likely to produce anything of substantial value. The problem was the bullet, not the cartridge.

Seems like we've more than adequately addressed those problems in recent years.

Yup. Absolutely correct. I firmly believe that the .45 ACP is the best ever Sex Crazed Zombie Stopper to come down the pike.

Agreed, with a three other "old timers" RIGHT there with it; specifically, the .357 Magnum, .44 Special, and .45 Colt.

Give any of those 4 a good bullet, load to standard specs, and stuff has a nasty habit of getting very dead, very quickly.

I have pushed a lot of cartridges to the real limit.

A) The weakest cartridge:
10mm

B) Very weak cartridges:
30 carbine
25acp
7.62x39mm

C) Average cartridges:
40sw, 9mm, 45acp

D) Above average cartridges
22-250, 243, 6mm Rem, 250 Savage, 257 Roberts, 25-06, 260 Rem, 6.5x55 [US brass], 270, 7mm-08, 7x57mm, 280, 300Sav, 308, 7.62x51mm, 30-06, 8x57mm, 338F, 358, and 35W

E) Strong cartridges
6.5mm RemMag, 7mm RemMag, 8mmRemMag, 264 WinMag, 300 H&H Mag, 300 WinMag, 338 WinMag, 350 RemMag, 375 H&H Mag, 458 WinMag

F) Super strong cartridges:
223Rem, 222Rem, .222 Rem Mag, 204 Ruger, and 17Rem

G) Cartridge so strong, the primer will pierce before the primer pocket grows:
32 S&W, 38 S&W, 22BR, 6mmBR, 6x47mm, 6.5x47mm, 7mmBR, 30BR, Lapua small primer 308

There is a guy out there on the internet that can calculate all this with Von Misses equations. I have to measure it.
It is not rocket science to get the answers. Cross section a 45acp case head and a 10mm case head.
The brass between the extractor groove and the large Boxer primer pocket in a 10mm case head is paper thin. Duh!

Still curious as to what you were running the .45ACP to 50k PSI in...

a) 19 ounce Republic arms Patriot 45 acp pistol and worked up to 460 Rowland loads and kept going higher in May of 2000. The manual said no +P, but the factory gave me all the parts I needed. Now manufactured by Cobra.
That pistol was designed by Nehemia Sirkis.
The recoil is something else.
I ordered that pistol specifically for that work up.


b) I put a Shilen .452" 26" long bull barrel on a 1903 Turk Mauser and shoot groups at 100 yards.

As a writer I always felt that the .38, the .44, and the .45 were the Holy Trinity of handgun rounds.

Now admittedly the .38 S&W is more of an altar boy (especially when compared to the .38 Special) than say a saintly 9mm or that high priest of .38s, the .357 Magnum. Much the same can be said when sermonizing about the .44 and .44 Magnum, the firing of which from a snubbie can be a truly religious experience. But in my holy book the .45 reigns supreme in Handgun Heaven, be it the thundering of that avenging angel, .45 Long Colt, or the most deserving of our worship, the .45 ACP.

I take it as a statement of faith the nothing will banish the evil ones to the darkest corner of the grave yard faster or better than the gawd-almighty 1911 in .45 ACP.

Truly, it is wondrous to see the miracles it has wrought.

Those who do not practice the "old time religion" may hand load to their hearts content and indeed they may approach a state of rapture... until they have to go into a store and buy a box of ammo over the counter and then WOE! but they will be found lacking when the moment of judgment in a dimly lit parking lot is upon them.

Here endeth the sermon. Go forth, be armed, and sin not with a micro .40 auto.

In the case of the .45 ACP and most other handgun cartridges pressure is incidental and important only as a factor in bolt thrust. Parts will start breaking down due to bolt thrust long before a barrel suffers pressure damage.

The top handguns during the development of the .45 ACP ran at around 3,500 lbs. of thrust. My guess is that Browning used that as his design limit. Since the .451" diameter was already mandated the pressure was limited by default.

Spot on analysis.

need to hold one of the variables constant or your comparing apples and oranges. Jog where were you when major 9 loads were being developed?

Really?

You'd be curious about some of the 45 Colt loads I used to run too. Especially some in the "weak" SAA. Sadly, they'll have to remain unposted in order to protect the not-so-innocent.

You're a bad influence. Especially on me.

Loaded to the levels you're speaking of knocks it out of the category of an ideal fighting handgun, even if it might make a fine deer round, due to sharp recoil and slow recovery time, even in a full weight service gun.

Recovery time is faster than for a 45. The slide returns to battery with such speed that it hauls the muzzle down. I get that interesting effect in both my Delta Elite and my G20. I never would have believed it until I experienced it. I can rip off an 8 rounder faster and a mite better with the Delta than I can with my 45 Combat Commander.

The 10 is a great round. In factory loadings, easily obtained, it usually trumps the 45 ACP. In those loadings, I think it makes a slightly better woods gun. Col. Cooper originally put it up as the heir-apparent to the 45. It never materialized and Cooper fairly quickly went back to his beloved. The FBI killed it as a combat cartridge when they dropped it and the 40 S&W maxed out in its development.

As it stands, the biggest argument against the 10 is its limited availability. Like a lot of other cartridges, you can get it if you've got a Cabela's around or other well-stocked gunstore. Walmart doesn't carry it.

As far as competing with 44 Mags and 41 Mags for truly dangerous game or dangerous animal protection...it doesn't. The only way it does is if you are using mid-range loads in the former and full-power in the latter. It also generally gives you more firepower. While I like firepower, I personally don't want a weaker round in this situation, just to get more rounds. I'd a lot rather have a 10 in dangerous game lands than I would a 32 ACP.

I don't have a 10 anymore. I've thought about getting another mainly due to the fascination shown here. I don't really need one though. Good round, if you like it, and want it, you have my blessings.

There was a lot of ink wasted in the gun rags back in the day, about how savage the recoil of the Delta was. When I first shot mine, I couldn't tell much difference between it and my cousin's Officer's ACP, which we were shooting side-by-side. I never could tell much difference between an Officer's and a full-size 1911 either. I've never done any recoil recovery tests, but it makes sense to me. Of course, I don't see a whole lot of difference between the 9 and the 45 either, real-world, I mean.

Minnesota?

I'm not sure about the meaning of your question, but the major 9's were developed to increase magazine capacity and to generate enough gas volume to make compensators effective. In addition to recoil control, compensators also reduce slide force via a number of different mechanisms depending on the design.

However, none of that reduces or increases bolt thrust, but they do affect how a pistol design manages it.

Gentlemen I can tell all of you, that my Glock model 20 in 10mm caliber is NOT excessive on recoil compared to any .41magnum pistol. Now in a Dan Wesson or Smith & Wesson the recoil is more yes, however the Glock in 10mm is less than a .45acp model 1911. Recovery time is faster for those of you who have never fired a Glock 10mm!!!

No Pounds PER square inch


http://en.wikipedia.org/wiki/Pounds_per_square_inch

"The pound per square inch or, more accurately, pound-force per square inch (symbol: psi or lbf/in2 or lbf/in2 or lbf/sq in or lbf/sq in) is a unit of pressure or of stress based on avoirdupois units. It is the pressure resulting from a force of one pound-force applied to an area of one square inch:"

The Glock I had didn't recoil badly at all.

You're both right. Lbs. (the force) divided by square inches = pounds per square inch.

Hey, no kidding? Thanks for that. Just what is the difference between "divided by" and "per" though? I guess being an engineer for the last thirty plus years I never figured that out. Maybe I should have attended the University of Wikipedia.

If you actually read my post you might have noticed I was trying to explain the proportionality of force, area and pressure to someone who thinks it works backwards, and by saying "divided by" instead of "per" it might make it easier to visualize. I guess it only made it easier to gig me using google. Yep, you got me good there.

I did not mean to offend...

You being an engineer, most likely use the statements interchangeably.

I can understand why you saw it as a gig even though I did not intend it to be.

Well, sorry to be offended. The "divided by" is not really a real term. But as JOG posted, in essence it means the same thing. Since I was posting about how if pressure remains the same, and pressure is force divided by area, the force and area must be proportional, I thought it would flow easier if I changed "per" to "divided by" to be more visual. But following the law of unintended consequences, it probably confused more than it helped, so maybe it wasn't that great an idea.

I have shot 40 gr H110 405 gr cast 2.1" in 45 Colt brass with large rifle primer in a .410 shotgun.

45 Colt brass is very strong... except the wimpy rim.

First of all, as a defensive round against even large bears, some 10mm loads have plenty of penetration. Double Tap's 200 gr. wide flat point pushed at 1150 fps. shoots through three 2.5 gallon water jugs placed end to end. That's about 36 inches of penetration. The only jacketed bullets I know of in the .44 Magnum that can match this are those bullets designed for .444 Marlin velocities.
Second, as far as "speed of recovery" goes in a shooting, it only matters to those that compete in matches. On the street, frankly, one of the biggest mistakes made is literally shooting too fast. Only hits count, not how fast those rounds are fired. The other thing is that if one or two central mass hits don't do the job, you'll need to stop, and put the bullet into the head. Almost impossible to do if you are doing your best to get your rounds on target as fast as possible like you would in a match.
Another thing is that the ammo companies abandon the 10mm as a combat round because they thought they could do better with a lighter gun in a higher pressure load than the watered down 10mm load in a heavier gun. So we got the 40 S&W. Smith and Wesson's 40, the 4006 is lighter and does hold more rds. One more. One only. And you have to put up with a more critical to load round in the process. No thanks. E

Why sure, a FMC .357 is prolly great for bears too. As you say, no thanks.

As to the rest, how many LE agencies now issue the 10?

I've never loaded that.

None that I'm aware of. Nor do any issue the .44 or .41 Magnums to my knowledge.
No, I wouldn't hunt any kind of bears with a .357 Magnum. Nor would I hunt Black Bears with the 200 gr. wide flat point Double Tap bullet. But to shoot into the skull of a grizzly, either the .357, 180 gr. wide, flat point cast or the 200 gr. wide, flat point cast load in the 10mm should work. E

We weren't talking about .44 Mags and .41 Mags in regards to LE though. You were talking about the 10 v. the 40. The 40 may be even more popular than the 9 in LE right now, though I don't have the stats. There's just no real reason to carry a 10 in dangerous game country when you have better options. The 10, OTOH, still makes a lot of sense for personal defense or LE. The 10 makes a fine woods round where truly dangerous game is not on the table. I wouldn't want to tackle Griz with the 10. So for most of the lower 48, it's great.

I will have to challenge that. Shoot, side by side, a Browning High Power in 9mm and a 1911 (standard size, all steel) in .45 ACP. Very noticeable difference in recovery time and felt recoil.

Actually we were talking about the 10mm vs. the .45 ACP.
Frankly, in my book, you are a fool to hunt grizzlys with any handgun unless you have a guy with a heavy rifle backing you up.
As far as getting the job done with a head shot, I'm confident it, the 10mm would work. I understand that Phil Shoemaker seems to think that a .357 loaded with Federal's hard cast 180 gr. bullets will work. He, of course, carries his old reliable .458 Win for serious defense against big bears. E

RufusG

Thanks for understanding...


T

~shrugs~Maybe I wasn't clear. I know there's a difference in recoil, as far as personal perceived recoil, I can't tell a lot of difference. Part of it could be that I tend to shoot 45 autos for pleasure more than my 9's. As such, lots of times I'm shooting standard ball ammo or not-real-hot reloads with the 45. With the 9, I'm usually shooting hot, bordering on real hot stuff.

On the hunting thing, I think most here who are toting the 10 in Griz country are doing so for personal protection and not hunting purposes. If I go hunting for a Griz, it will be with a 45-70 or the like, in a rifle. I will have a 44 Mag. or 45 Colt for backup.

That explains it.

its just a linear momentum problem, if your going to use bolt thrust lets throw in bullet thrust. pressure is more important , if the other were correct the various makers of barrels would have never made supported ramps, beefed up the 1911 to the LAR grizzly, made 38 super + brass, invented the 9x23, wild catted the 10 to the 35 Dillon, on and on.
so the higher pressure 308 was accepted over the lower pressure 30-06.
the 45 and 10 are what they are today because of the gamers, not the other way around, they are responsible for the market demand which gave better parts to replace most of the pos stuff in the earlier colts. which brings up another question why do IPSC and action shooters use the 40 instead of the 10?
congrats to the poster who can shoot a hot 10 faster than a major 45 in the same configuration -- you have just done what 10000 IPSC shooters have tried to do for 20 years and failed. The whip down you describe is called the "pogo stick effect" and is the last thing you want.
Multiple shots may not be somes forte, but a controlled pair or a double tap will beat a single any day.
and why are muzzle brakes on pistols called compensators and when on a rifle they are called muzzle brakes?.

If "pressure is more important" than bolt thrust in handgun design, explain the design differences between the 24,000-psi .22 Long Rifle and the 21,000-psi .45 ACP.

Now when it comes to grizzly bears gents, I will agree 100% with "Eremicus", this critters are faster than you can imagine and can soak up lead like a spronge does water.

I have personally seen what grizzly can do and the effects of 4 men shooting at it while it charged. Only a brain shot stopped that bear that day and the other 6 shots that hit didn't even slow him down. No sir! I want a damn big rifle facing one of those charging bears and the minmum pistol caliber for me would be the .44mag........pray I never had to use it too.

Now on subject, the 10mm is more versital than the .45acp, it shoots faster, flatter and will expand a HP bullet out to 3/4 of an inch and also out penetrate the .45acp.

Bolt thrust is a really bad term. Its really an impulse. thrust is the stuff rockets and jets use. rate of change of mass with respect to time. Which configuration--- a 22 conversion kit used on a kimber 45 frame? not alot except ones a blow back and the other doesn't. Again an apples and orange comparison. How about something like a browning hp with side cuts that won't take the pressure without splitting when compared to a barsto in a 1911 configuration? A little more to the point.
the op stated the conditions that use factory loads, but if you get reloading in to it, the 10 is neither flatter, faster or more expandable than the 45. For me a min. on the bear charge would be a 454 casull or a 500 sw.

the pistol to use when a Grizzly bear is chewin on you?
Is for shootin yourself in the noggin and ending the agony!

You might kill the bear with one too, but odds are on the bear!
You might as well make it easier for him!

Yep, "bolt thrust" is a horrible term. It's rifle terminology and since semi-autos and revolvers don't really have "bolts" in the rifle sense it doesn't fit. I'm all for someone inventing a new term. You're spot on that bolt thrust is an impulse: Area x Pressure

The '.22 LR vs. .45 ACP' design question was intended to show that despite the higher pressure of the .22 LR very few elements are needed to manage it. The .45 ACP on the other hand requires a locked breech and a comparatively delicate balance between Barrel/slide weight and spring weight. Those elements are not needed to manage pressure - they manage bolt thrust. Similarly, the 9mm +P operates at a higher pressure than the 10mm Auto, but it would be hard to argue the 10mm Auto is easier on pistols.

It's no big feat for barrels, cylinders, or chambers to handle 50,000-psi. The trick is designing the supporting cast - the pins, slide stops, cylinder bolts, frames, and springs that have to take the pounding.

JOG, is correct. Bolt thrust and pressure are both key components and both must be acounted for in a design. The 10mm loaded to the same pressure as a 45 ACP will have less bolt thrust. Because of the smaller diameter case

10 and 45 loaded to the same pressure don't have the same momentum comparing apples and oranges again. The 45 doesn't need a locked system, however the spring system may require 3 people to operate. several designs in the last 30 years, but non caught on. High PRESSURE is what needs locking systems so the pressure has time to fall off before opening goes for rifles and pistols. If in doubt stick your thumb over the cylinder gap on a 44 mag or 454 next outing. Even though a 1911 has 3 locking lugs the total area used is only about 50%.

Then why don't the .22 LR, .25 ACP, or .380 Auto need a locking system? All three have more pressure than the .45 ACP.

You're right in the respect that one of the functions of a locked breech is to delay opening until the pressure subsides. The other function is to retard slide velocity by adding barrel weight at the start of the recoil cycle when the recoil spring is still semi-relaxed. By the way, one blow back design that caught on (sorta) is the Hi-Point and they did it by increasing slide mass.

However, it isn't pressure that moves the slide. If you want to call it "momentum" that's fine with me.

There are other factors that go into bolt thrust as well, such as cartridge shape, and the condition of the chamber. Take a straight walled cartridge for example, often those cartridges exert little to no �bolt thrust� at all. PO Ackley proved this when he shot a .30-30 AI in a model 94 Winchester without a locking block; no problem at all.

Now do the opposite, and have a radically tapered cartridge and see what you get. The bolt thrust of a 9mm Luger is far greater than that of a .38 Super even though the .38 Super is a more powerful cartridge. That�s because of the sharp taper of the 9mm.

I point this out to call attention to the fact that there is no ONE issue. It STARTS with pressure, and then things expand beyond that depending on a whole lot of things. To make a singular statement that everything is about pressure is a faulty mindset. How is that pressure applied, what are the effects, how do you want to control that pressure. These are things that determine how arms are designed. Pressure is but a starting point.

Kevin, I don't disagree, but PO Ackley's test only determined the force wasn't directed to the bolt - not that the force didn't exist.

That's one of the reasons "bolt thrust" is a crappy term. Newton's laws of motion prove the forces counter to the bullet's acceleration must occur, but the variables you mention show we can't be sure where they will be directed.

You're going to have to explain this one further because I'm not seeing how this works. The pressure in the case exerts a force in every direction. It pushes on the back of the bullet so it goes out the barrel. It pushes straight back on the case head causing the events which make the gun cycle.

If the cases are absolutely straight wall, the forces acting on the side of the case have no component operating on the same axis as the bullet or case head motion. If the case is tapered (narrower), there would be a component of force acting in the same direction as pushing the bullet, and this would act to OPPOSE the rearward movement of the case head.

So what is going on here as a result of the taper to increase the bolt force?

When the case wall is straight, the pressure pushing on the chamber is much greater than anything pushing forward or backward, so the case tends to cling to the chamber instead of back. The tapered case just decreases the leverage, and the shape causes it to push backwards; simple as that.

For that much, if you change "pressure" to "force", I agree. After that, I'm not so sure. Maybe it's a matter of friction. A straight walled case continues to drag along the chamber, whereas a tapered case "disengages" from the chamber as soon as it moves slightly rearward and fiction is no longer in play..

Exactly. My point is more about point out that there are few things that are absolute. Yes, the force is still there, but it isn't able to overcome the force pushing toward the head of the case. So while there is force on the head of the case, in essence, there is no force on the bolt face.

Again, the point is just that things are often much more complex than simple absolutes.

Correct.

pressure is a very specific term,-- of course other things come into play, but just as much gun design is so broad of a term its useless. its easier to hold pressure as the center of discussion than gun design, all models only highlight certain features. Here again you refer to pressure to explain the change in coefficient of friction, (brass rebound)and not gun design.
I prefer to use the amount of work done, or being able to be done by the amt. of energy stored in the charge, either expressed in thermodynamic units (easy to calculate the force) then integrated to get the work, excess of course is what you call " beating up the gun" rather than thrust or momentum. Using momentum has the advantage of using bullet mass variation to compare between calibers. Another fun way to "model" is in the molar concentration on the nitrates involved if you want to look at it on another level, (apply the gas laws).

If the chamber has any lube in it, then the friction is reduced and the case has less cling to it

Lotsa variables, also how smooth is the chamber. I believe there is an effect there for friction. I don't know how big it is, and I'm not convinced it's as big as Kevin says it is. But during the pressure spike after ignition, the case is also expanded a bit against the chamber.

My experience is that My S&W 57 6 inch .41 Magnum with 175 grain silvertip is about a 100 fps faster than my Glock 20 with the same bullet. As to the 10 mm having more energy at 100 yards than my .45 ACP at the muzzle: 200 grain JHP .45 ACP does 1190 fps from 5.5 inch revolver with max load of 12.4 grains Blue Dot, +P load, less than 23,000 psi. 10 mm 200 GR. HDY FMJ does 1172 fps, 8.2 grain Longshot, 23,900 psi according to Hodgdon Reloading. Granted, I used a revolver because I didn't want to install the spring set in a .45 ACP semi-auto but the difference isn't nearly as great as some suggest, with the same bullet weight.

The S&W M57 is going to lose a touch of velocity due to the flash gap, but there's around 2.5" more barrel length.


Same deal, except 2" more barrel length for the revolver.

Your comparing apples to oranges.

What ? The 41 Magnum only beats the 10mm w/ 175 gr. bullet by 100 fps. ? Sierra lists four powders that can push their 170 gr. bullet 1450 fps. in the 41 Magnum. Never saw a load that developed over 1300 fps in the 10mm w/o excessive, tested pressures.
Lots of data shows the 41 Magnum at 1400 fps. plus with 210 gr. bullets. Good luck trying to get that from the 10mm with a 200 gr. bullet.
Likewise I have no data, and that includes +P data, that gives a .45 ACP load anything much over a 1000 fps with a 200 gr. bullet.
BTW, all of my data that shows the 10mm doing 1150-1190 fps with a 200 gr. bullet is right near maximum pressures.
I might also add that the 200 gr. Hdy XTP in 10mm has an SD of .179 and a BC of .199. The 45, 200 gr. XTP has an SD of .140 and a BC of .151. E

Norma had at least two.

Buffalo Bore has a 180 going 1350: http://www.buffalobore.com/index.php?l=product_detail&p=114

So does Double Tap: http://www.doubletapammo.com/php/catalog/product_info.php?cPath=21_25&products_id=122

And, DT has another 180 at just over 1300, too: http://www.doubletapammo.com/php/catalog/product_info.php?cPath=21_25&products_id=381



1400+? Nope.

Again, Norma had the 200s doing 1300.

Double Tap has 200 WFNGCs at 1300 (http://www.doubletapammo.com/php/catalog/product_info.php?cPath=21_25&products_id=105), 200 JHPs at 1250 (http://www.doubletapammo.com/php/catalog/product_info.php?cPath=21_25&products_id=40), and 230s at 1120 (http://www.doubletapammo.com/php/catalog/product_info.php?cPath=21_25&products_id=158).

Buffalo Bore has 200s at 1200 (http://www.buffalobore.com/index.php?l=product_detail&p=113) and 220s at 1200 (http://www.buffalobore.com/index.php?l=product_detail&p=219).



Again, check Buffalo Bore for 200s at 1000+, and Double Tap for 230s at 1000+.



I'd hazard a guess that either of those two companies have better pressuring testing equipment. Just a hunch...



Yep.

There's no contest here the 10mm is superior to the .45 acp..

Depends upon the intended use.

In the .41 mag, with 210 grain XTP bullets over Lil'Gun Hodgdon shows a starting load making 1505 fps with the starting loads, and 1626 fps at max, with 29,900 c.u.p.

That's probably out of a pressure barrel, and a real world revolver would lose some velocity out of the barrel cylinder gap, but in my own experience I saw 200's run in the high 1400's out of an 8 & 3/8 M57. I'd wager a 200-220 gr Keith style bullet would do a little more.

I like the 10mm, have two of them, and someday might tinker with a M610 revolver, but the 10mm is not a .41 mag.

Oh, in no way am I saying the 10mm is the equal to the .41RM, when both are loaded to potential.

Simply not the case at all.

original poster doesn't say 45 acp, everyone went with that to make some sense in the postings, now off to 41 mag. Since were on apples and oranges again lets compare the 41 mag to the 454, its a 45.

Both of Norma's loads were pressure tested at well over the SAAMI limits. Buffalo Bore isn't even a member of that industry group. Double Tap's ammo was just posted as being "overly optimistic" in their velocity claims. This particularly important with the 10 mm round. It goes critical rather easily. I found that out using some of Accurate Arm's data for their AA#2 powder. They don't list any data for it now.
The other thing is that you really don't need to push the 10mm's limits to get outstanding performance with it. A good 180 gr. class bullet or a 200 gr. bullet at the general level of performnance does a very good job w/o any extra effort. E

Oh, no disagreement there, whatsoever.

Here I am saving money for a 1911, and of course I find a Smith 610 on sale locally. Hmmm....

One only has to visit U-Tube to realize what the penetration of a 165, 180 and 200 grain bullet will do coming out of a Glock model 20 pistol.

The hottest load I have shot with a 10mm is 14.2 gr 800X 200 gr and the primer pocket gets loose.

The hottest load I have shot with a 45 is 16.5 gr AA#5 185 gr and the primer pocket gets loose.

A 610 on sale locally would be tough to pass up...

Imagine that! Hard to believe a charge 70% over recommended max would blow a primer!

You are using a charge that is near max for a 135 grain bullet. Size matters.

Well FWIW I can tell you to be wary of the Hornady 4th Edition loads for the 155 gr bullet in the 10mm. They show a 13.9gr max with AA#7. I tried 13.0 gr and they ran 1400+ fps and bulged the case head over the feed ramp - Delta Elite with a Bar-sto barrel. Either they had a slow lot of powder, or I had a fast one, one of the two. 12 grains was fine, and so were Norma factory loads, so I don't think it was an over-ramped barrel.

Clark;

Here's your post on those loads over on TFL:



If 7.8 grains was generating 32500 psi, just what do you think 14.2 grains was generating? QL doesn't list 800x as a powder choice.

The .45ACP load QL estimates pressures around 70k PSI, and I'd be rather surprised if the 10mm overload with 800x wasn't comparable.

Considering these were the other loads listed in that same post, I'd have to wonder how much you actually LIKE your hands and eyes...

After having fired an old Colt Peacemaker in .38-40, I'd be very tempted by a Convertible Ruger BH in .38-40/10mm. E

E;

Ruger made a limited distributor (Buckeye) run of those about 20 years ago.

I think I know a shop that has one; I'll pass that info on if they still have it.

I have two old peacmakers in 38.40 but don't shoot them. On the other hand i have that ruger buckeye shooter which i have shot in 10mm. Haven't in 38.40 yet due to the cost of ammo and not having bought the relative expensive brass for reloading.
that 10mm round of 200 grains xtp flies out of the ruger at around 1300fps.
the first peacemaker i fired at about six years old after bugging my dad. It was carried in territorial days here in arizona. One round, and i didn't tought it for years.
I take certain humor that it is ballistically similar to the .40s&w today.

I see there is now a .38-40/.40 S&W convertible Vaquero available now, FWIW. I guess you could fix it with a few turns of a 10mm reamer

The only revo I like better than a Bisley Blackhawk is a N frame Smith, and I found one of them. Decisions...Decisions...

Not a good idea for a putz, but I have been doing high pressure constantly for 10 years in dozens of cartridges.

Hey E,
You remember the "Freeway Killer" who took pot shots at motorists along highway 80 near Auburn in the '80's (killed 2 IIRC). When he was caught, that's what he was caught with.

Psychotic idiot, but good taste un guns.

Figured you one and the same.

I like me more than that.

I could test a whole lot pf dumbphuckitude, 'til it caught up with me, and figure myself smarter than the average bear in the interim.

You still didn't answer the pressure questions one the overload, however, and I'm curious as to how you actually test that pressure, too.

BTW - the argy Mauser is a slick rig. THAT makes sense.

I have strain gauges and Quickload predictions and it is all abstract.

The effect on the brass is the reality.

Some people do not agree with me, which reminds me of a joke... er true story 30 years ago...

A New York cab had a flat tire. The passenger suggested that the cabbie put the spare tire on. The cabbie protested with a thick Pakistani accent, "I cannot. My training for this job was that I cannot drive anywhere without an inflated spare tire in the trunk. And if I change the tire I will not have an inflated spare in the trunk."

Clark;

What you do, with your own stuff, is your call. As I said, I like me more than that. If it's being a "putz" when I don't really want to set a grenade off in my hand, then so be it.

So, if you have the strain gauges and a QL version that lists 800x, what were the "abstract" numbers relating to the PSI levels of the 10mm and .40S&W loads?

I've shot several 40's. They strike me as an intnese, loud, high pressure round. I understand they go critical easily when reloaded as well. For some reason more critical and not as accurate as the 10.
The .38-40, however, was a much nicer, quieter round getting the same ballistics w/o nearly the fuss. Should be easy to for in a modern Ruger. Lately I've seen winchester brass for sale in Cabela's new catalog.
Sorely tempted guys. Now, if my account will tell me how badly my taxes came out..... E

Note to self - never let Clarkma work up a load for any of my rifles or handguns.