Home Forums Reloading Big Game Rifles .270 win vs .280 rem

The MOST reliable method would be to know that physics dictates that a like wt bullet being pushed by the same powder at the same velocity from the same sized case will create less chamber pressure when pushed down a slightly larger bore. ALL OTHER things being equal of course. AND the chambers being cut to identical specs for each respective caliber. Its a function of physics...and you can talk about your subjective real world observations...but physics don't change. So many things make creating a true actual comparison almost impossible...but again, physics dictates that all things being equal...well you know...I already said it.

Royce, I too have considerable experience with the 44-40 ackley, it's a pity we don't hear more about this excelent wildcat. I made my first one from a 1873 winchester my grandfather had used in the Blackhills. It was a fancy engraved version originaly owned by Teddy Roosevelt and so documented. I got bored with it the way it was and rechambered it to the Ackley version, for the sake of safety, I marked the new name with a dremel tool on the gun in a few obvious places. Unfortunatly, It will no longer feed from the magazine so it's now a single shot. Then it hit me, the 44-40 improved deserves to be in a good single shot. Gramps had also left me a low wall in 44-40 that was the perfect candidate. It had been originally shipped to Buffalo Bill who had presented it to Anne Oakley. I even have a few original photographs of her with the rifle. After rechambering and marking the gun in my shop, I was not dissapointed by the improved ballistics. But the increased recoil of the little gun with the crescent buttplate is not pleasant. Then I read your post and the answer was obvious, custom sling swivels in extra heavy weight. A quick internet search turned up lots of depleted Uranium but everybody says it is the devil to machine. The only other thing readily available is weapons grade plutonium. UPS won't ship either one. Fed Ex says they will deliver but I have to pay a Haz Mat fee for Plutonium. Do you think it is worth the extra expense given the shorter half life of plutonium,as at some point it will will lose any advantage in atomic number? Maybe I'll just use a 270 with shells from Kmart for everything. My sisters' cousin used one for years, day and night and he killed lots of things. Of course he was in great condition because he was allways running from the law. He only needed one rifle and the dang govment wouldn't let him buy no more after that domestic trouble at the trailer park.

I don't know why you guys ackleyed the .44-40, when all you had to do was neck it up to the .447-40 and you could have gained way more velocity, range, and killing power.

-Lou

280 Rem.

Please rationalize how the laws of physics have been defied in 5 cases of each caliber?

I agree, as I stated previously but you obviously did not read, you are correct on how it should be, but is not that way.

5 different guns in each caliber, no coincidence.

How many of each caliber have you worked with and evaluated? I know you are getting very high velocities with at least 1 280.

The velocities you are getting, I've only seen with Federal HE stuff....I won't / can't handload any of my 280's that high. Case expansion is WAY too much. Have you pressure tested your loads by some means?

MM

Bill---what , if any, effect do you believe the rifle's chambering has on the results. Not trying to make a point here, at all. Just curious.....I've seen rifles with tighter chambers shoot the same loads at equal to or higher velocities than "sloppier" chambered rifles with longer barrels....

Not really.




Gun looneys shoot 280's. Hunters shoot 270's.



Well, we're up to what?, 13 pages now...........




I prefer the 270....With apoligies to Mark D and his most excellent term for the 270 (Improved 30-06) , I was calling the 270 an "Efficient Magnum" 25 years ago. Operates at 65k psi, pushes a high BC and Sd bullet at good velocities with a 22 inch barrel.

If one goes a tad over max SAMMI pressure with a 280, it is more or less equal to the 270....

My chrono suggests 280's tends to like bbls at 24 inches or more, one reason I stick with the 270.......

I couldn't resist, this thread was getting off-track

Casey

Ken,

You make a good point.

Chambers can & do have an effect as you describe; large chamber = lower pressure/velocity & vice-versa.

No real way to quantify though and therein lies the problem.

W/O measuring chambers on all the guns involved no way to determine if some were bigger or smaller.

Bullet bearing surface definitely has effect too, as does barrel bore diameter within a given tolerance.

I just find it striking that the pattern of higher velocity at same or lower (apparent) pressure in 5 cases of each caliber has favored the 270.

280 Rem is right - it shouldn't be that way.

But I'm equally sure the data I've collected over the years is correct too.

MM

Nice philosophy, "When all else fails(logic), start some schit...."......grin

Casey

s

I've loaded for 7 or 8 different 270 Winchesters but only 2 280's. I currently own 2 Beretta Mato's that are identical other than that 1 is a 270 Winchester and the other a 280 Remington.
Since the rifles are about as nearly identical as can be had someday it might be interesting to do some comparative tests between the two but right now I don't own any pressure testing equipment other than a Chronograph.
I've got a perfectly fine blade micrometer that I used to use for head expansion measurements but have come to not trust the technique for anything other than VERY rough estimates. Measuring case head expansion just isn't a valid way to compare the pressures between two different rifles. There are mathmaticians and professional ballistitions that can explain this to you a lot better than I can.
I'm not saying that you didn't accurately measure what you say you did, I'm saying that there are so many other factors that what you measured can't be used to make accurate pressure comparisons between your different rifles. Did you use the same lot of brass for both caliber? Easy enough to do between the two and even using different lots of brass could sway your data the other way...............................DJ

DJ,

No, the brass lots between 270 and 280 were different.

Yes, there are other factors at work. Both are great guns and I love 'em both or I wouldn't have 'em.

Guess the bottom line for me is when the same trend shows itself in several rifles, that seems more than coincidental.

I'll just leave it at that and call it a day.........to each his own thoughts.

Regards,

MM

"perpetual 270 envy."

After 14 pages, that one said it best.

My advise, since no one asked, buy the one on "sale".
You'll never know the difference. BT

2MUCHGUN: Just a thought on your comments regarding chambers.Rifles in the same caliber do not differ in their velocities as a result of chamber dimension differences. They really can't because the differences are so small. I strongly suspect it's the barrel dimensions,bore finish, design of rifling, etc, that causes resistance (more or less) to the bullets travel down the bore. All of this stuff effects pressures,and velocity, etc. To say nothing, of barrel length.

When you think about it, it's really not possible to have EVERYTHING exactly the same in each individual rifle when comparing these cartridges.You have to look at a big cross section of rifles at known pressure levels to draw a valid conclusion. Also, what pressure a person is willing to work with has a lot to do with making one cartridge look "better" than the other......

Guys, You have finally convinced me that the .007 difference is insignificant. Therefore .264 is not necessary as we already have .257 in the U.S. The fact that it has heavier bullets available just does't matter to me. The fact that it has been proven in serious competition to be more accurate and has more match grade bullets available just doesn't matter to me. The fact that Boyle's Law regarding gases,pressures and volumes indicate that all other things being equal one can push 120 grain bullets faster in a 6.5-06 than a 25-06 doesn't matter to me. It just doesn't matter because both of my rifles in 25-06 with my handloads which have never been tested for pressure do chonograph faster than my untested loads in the 6.5-06. Besides 25-06 is a gun for serious hunters. Only gun nuts like 6.5 rifles and everybody knows they aren't real men anyway. So don't confuse me with your silly ideas, I have made up my mind. Only a girly man wants a gun with anything metric associated with it.

Just for the record the effect on the life support system of game animals with 270 vs. 280 is practically identical. But I do think I have observed minor differences when using comparible bullets. I've used 150 grain Partitions in both. The .284 Partition seems to be a tougher bullet, both bullets exit but wound channels and exit wounds are bigger in 270 than 280. I've used 140 grain Hornady btsp in 270 and 139 grain Hornady btsp in 280, despite pushing them a little faster in 280 they exit more . I've recovered a lot of the 270 hornady bullets just under the hide of deer and hogs looking like classic mushrooms. The 280 hornady bullets keep punching through. I've indicated that I think the 7mm bullets may be built a little tougher to withstand magnum velocity. Probably 99% of the 270 rounds fired are in 270 winchester not one of the 270 magnum rounds. In 7mm you have plenty of smaller rounds available, but at the end of the day I'd bet 90% of 7mm rounds fired are in one of the magnums. I've observed the same tendency in other bullets as well although I have less experience on game with them. For example I've never recovered a 140 grain ballistic tip fired from a 280, they all exited too. Granted both calibers did their jobs,nothing ever walked away from a well placed shot from either one. I've indicated that I really like both rounds, I've just observed a little more velocity and a little better accuracy with my rifles and loads with the 280. Others who seem to know exactly what they are talking about report no difference or give a slight advantage to the 270. If we agree to disagree about which round holds the edge in accuracy and velocity can we reach any concensus about what happens after after the bullets hit something. As a general rule I think 280 bullets are built a little tougher, are more prone to exit,and tend to tear up a little less edible critter. I also think the 270 may be a quicker killer on smaller big game animals because it's bullets are so explosive. The only bullets that I have used in 270 that didn't follow this trend are barnes X bullets which go through everything without exception and don't seem to care what diameter they are.

ruraldoc,
You can say that again, you can say that again!

Have I pressure tested my loads? Depends...how accurate does it need to be? Your casehead expansion method leaves a lot to chance with dealing with thousanths of an inch. I don't trust it to be accurate...starting with human error, and running all the way through chamber/brass/etc differences. I have run my loads through quickload. Its only a computer program, but I suspect it has some redeaming value, and though not 100% accurate, Id suspect its at least every bit as accurate as you hand mic'ing your caseheads.

My 139/140 loads running 3100-3150 fps showed pressures in the 59K-63K pressure range. 60K is SAAMI for the .280 and 65K is SAAMI for the .270. I load mine to .270 pressures. According to Quickload I'm doing ok...my 15 years experience running these loads backs that up...and the varying modern load data showing .280 loaded to 65K back me up as well.



You say you see factory stuff moving that velocity, but you can't handload it that high? The key to your above statement is "I wont...". You wont load that high...thats fine...if you don't want to, I'm not one to tell you what to do. If you're happy, then thats great. Don't fret...lots of people are afraid of loading the .280 to its full SAFE potential. Some people regard SAAMI as the aboslute max...not to be approached...I view it as the safe pressure to load to. SAAMI says its the maximum safe AVERAGE pressure.

I get a kick out of the posts claiming there are so many more bullet choices for the 7mm as to the 270. well DUHHH! the 7mm bullet market has to cover everything from the 7-30 waters to the lazzaroni velocities. the "small" bullet selection for the 270 is likely due to the fact that for most of the life of the diameter it was always designed for 270 win velocities. so it is totally possible to shoot a "cheap and normal" bullet from a 270 win and get perfect performance. A 280 is so middle of the road for 7mm that you could likely do the same. I have yet to exhaust my bullet choices before finding a slug a 270 won't shoot well. I think now that the wsm is on the scene and the 270wby has strong roots you are going to see "better" 270 bullets..........not that they have ever been needed in a win.

280Rem.

Just so you know, I DO like to get the most out of all the guns I load for, including the 280 Rem. That means the highest load that is safe, repeatable, and gives at least 5 loadings on the brass.

In order to do that, one needs to load to a higher than ideal pressure (as determined by whatever means are available) and then back down to a safe, consistent and reliable number.

Certainly, case head measurement does not give one a pressure value of any sort.

It simple tells you how much any given load in a given gun will expand that particular brass.

What it does do, and is my logic for using it because I have no other pressure measuring equipment (and obviously, neither do you, including Quickload) is that by measuring 10 or so cases before & after firing, you can see how much the case head will expand, remembering that every time the case is fired with that load, it will expand that much again...that means a cumulative effect.

About .0015" of case head expansion will generally make the primer loose - too loose to suit me.

Factory loads, supposedly loaded to SAAMI spec, some higher, some lower, generally show zero case head expansion.

Any 280 Rem loads, with 150 grain bullets that reach 2950 that I have used, pretty much all expand case heads .0003"-.00035" and to my thinking that's just too much to use......is it safe on a one shot deal, sure. But its pressure is most likely over 65K.

With me doing the measuring & evaluations, I'll take what the case head data shows anytime over relying on Quickload for anything more that picking powders and a starting point that probably won't blow a gun up but is just as likely to be too high a pressure as too low.

As for duplicating the Federal HE loads, those are very special and I know no of one who has been able to, I guess, except for you.

I think that data from multiple guns is significant and there appears to be a lot more people on here that have the their limits with the 280 to be somewhat below what your routine numbers seem to show.

Not saying you aren't getting them, just that IME, you are significantly understating your real pressure.

Unfortunately, we'll probably never know, so I guess as long as everyone is happy with what ther are doing, all's right with the world.

MM

Rural Doc: I,ve used both, loaded for both, shot game with both.Can't see a difference in effect on game. Agree with you there.
My experience has been mostly with 130 Noslers in the 270; 140 Noslers in the 280. I HAVE noticed, as you mention, that the 140 Partition is pretty tough to recover from game. I've used the bullet in the 7/08,7/57,280, and 7 rem mag and results were always the same; pass through's from about any rational angle. A friend thinks Nosler draws the jackets of 7mm bullets to the same thickness as 308's and so the 7mm tend to be somewhat tougher. He also opines that 270 jackets are closer to 6.5 in thickness. I do not know if any of this is true or not, but I have dug a lot of 130-270 Partitions from DEAD game; not so 7mm 140's, so maybe 7mm 140's are a bit tougher. In any event, this seems to be a byproduct of bullet construction, not any real difference between the cartridges.

On the other hand, I've also used 270-130 and 7mm-140 Bitterrots, which are very tough, heavy jacket bullets, in both the 270 and 280.There is utterly no difference in depth of penetration, wound channel, TKO, "Lights-Out Factor" or anything else, between the two using the Bitterroot.