Home Forums Hunting & Shooting BPCR Postell Bullets?

Thank you. sir! It will be much sooner than later!

Ed

I just answered your question nothing more or nothing less.

I try to rely on the info from BPCR websites reconizing everything has to be taken with a grain of salt. All Brent was saying is that the info given should be as accurate as possible.

[quote=derby_dudeI just answered your question nothing more or nothing less.

I try to rely on the info from BPCR websites reconizing everything has to be taken with a grain of salt. All Brent was saying is that the info given should be as accurate as possible. [/quote]

Derby dude you did not answer the question, and it was not directed at you in any event. The Danielson boy is the one that is throwing ignorant accusations around.
Now as for you there sir. I have not cost you one red cent. And I won't cost you one red cent.
If and when you can come up with proof that anything I put into these forums, that does not come from my actual experience , and is wrong you feel free to let me know. But I will guarantee you one thing buddy, I will never intentionally put one thing out that I do not know to be the truth, and IF I am not real sure about the answer or it comes on second hand info I will state that as the case.
Now either you and that bedraggled college professor with the chip on his shoulder and the monkey on his back either come forward and offer up hard proof to your claims that I have cost anybody other than myself money, or you shut your fat pie hole.
I still say if you can't afford to get into something then stay the hell out of it. Walmart sells 22 rifles for less than a hundred bucks and 22 shells in boxes of 550 for under 20, that may be the best route for you to go as the 22 is the first successful blackpowder cartridge.

I'm a bit late to the thread, but FWIW my Shiloh 45-70 has a POI at 400 yards that is 14 inches higher with paper patched bullets than with greasers using the same sight setting. The bullets weigh the same, have the same nose shape, and both bullets have muzzle velocities in the mid 1240s.

Those greasy grooves do catch a lot of air dont they SG.

Gunner

Thank you, sir.

Would you mind sharing the bullet specifics for me? I have pretty much decided on .45 caliber, probably .45-2.1" for my eventual BPCR.

Ed

Derby dude you did not answer the question, and it was not directed at you in any event. The Danielson boy is the one that is throwing ignorant accusations around.
Now as for you there sir. I have not cost you one red cent. And I won't cost you one red cent.
If and when you can come up with proof that anything I put into these forums, that does not come from my actual experience , and is wrong you feel free to let me know. But I will guarantee you one thing buddy, I will never intentionally put one thing out that I do not know to be the truth, and IF I am not real sure about the answer or it comes on second hand info I will state that as the case.
Now either you and that bedraggled college professor with the chip on his shoulder and the monkey on his back either come forward and offer up hard proof to your claims that I have cost anybody other than myself money, or you shut your fat pie hole.
I still say if you can't afford to get into something then stay the hell out of it. Walmart sells 22 rifles for less than a hundred bucks and 22 shells in boxes of 550 for under 20, that may be the best route for you to go as the 22 is the first successful blackpowder cartridge.[/quote]

My apologies for putting myself into your pizzing match with Brent. I was out of line. It won't happen again. Again my apologies.

More BS has been added to the dung pile I see, and another bloviator has joined in.

And a few lies are added on top of the just plain wrong advice and explanation.

Let's see, what would it take for a ballistic improvement for a bullet to gain 14" of elevation of a 400 yd target when launched at 1240 fps?

Now, anyone can do this at home so no reason to simply accept what I say as fact. Check it out on your own. I find the JBM ballistic program to be among the best. You can find it free to use right HERE.

Lets start with that grease groove bullet having a Ballistic Coefficient (BC) of 0.5. That is ballpark for a good target bullet. Let's pick our at 400 yds and then see how much we have to change the BC to get a bullet that is launched at the same speed and angle to hit 14" higher.

That would be a BC of 1.37. Now let's think about that for a moment. This BC is 270% of the original BC - just from stripping off the grooves. Does that sound reasonable to anyone? This BC is SO HIGH that the program prints a warning that the BC is simply wrong. And, of course, no human has measured a .45 caliber bullet with a BC fired from a shoulder weapon (or likely any weapon) because they flat don't exist.

So, Ed, when you ask for the specifics of that bullet, be sure that it doesn't actually exist in reality. It cannot exist. Or else be happy that you will not get the benefits of such super aerodynamics.

As for why a 14" higher point of impact, the fact is that bore diameter bullets will shoot slower than grease groove bullets of the same weight, from the same gun, with the same powder charge and all else being equal. This is easy to prove with a chronograph and I did exactly this 15 yrs ago. Bill and Don just forget these things.

And as most folks know, the slower the bullet, the longer it is in the barrel, the steeper the barrel is when the bullet exits the muzzle and the higher it hits on the paper. This is not news. It is the principle behind which gun makers have been regulating double guns for years. Hence, no surprise that The Bill found a higher impact. This is all well described in books on double guns (among other places) by well regarded authors like Ellis Brown (a gunmaker) and Graeme Wright.

Now as to the 1/2 to 2/3rds reduction in wind effects claimed by an ignorant keyboard "expert" (now I guess I should take off the quotes as he really is a KEYBOARD expert), you can run the same experiments using your favorite software patch like the one above. And what will you find? Well it will take a similar 200% increase in BC for a bullet to drop its wind effects to the degree Don claims. The fact is, that is simply not possible in the real world. There are no such bullets that are that superior to grease grooves. GIVE IT UP!

So, what is the BC of a top-drawer paper patched bullet in a .45? The best I have measured over 100 yds is about 0.55. That is it. For a 550 gr bullet. Maybe someone can make a bullet that will push up to 0.6 - I doubt it, I would bet against it, but maybe. A bullet with a BC of 1.37. BULLSHITT. Does not exist on Planet Earth with a shoulder fired .45.

By the by, the bullet I use at Lodi and at long range is almost always 537 grs. BC is right about 0.5 as I recall. Maybe 0.53 but I don't have my notes handy. That is not "light". In fact, it is probably slightly heavier than average among the shooters that actually compete in these games.

So, before you order up that magic $200 mould or lay down $2-3k rifle with especially fancy custom chamber and bore specifications that you heard about from these turkeys, be sure you verify what you are doing and that you can afford to throw away those dollars, because you aren't going to get what is claimed. You don't have to believe me, just do your homework on your own and you will find the same thing. Don't except on-line BS from anyone, especially these guys.

I've been shooting paper patches (almost)exclusively for just under 20 yrs now. Learned a little - enough to know bullshitt when I see it. I see a lot of it here, and knowing a little about the off-line records of the windbags producing it, it comes as no real surprise.

Brent

PS. If paper patched bullets were as good as Don claims, you can load up your BPCR and sign up for F-Class Nationals. You would clean their clocks. Please let me know when you attempt this as I want to lay money on the other guys.

Brent, I didn't say that the loads were identical, or that they use the same powder charge. I said that the bullets weighed the same and had the same nose shape and had velocities in the mid 1240s.

I frankly don't care whether you believe it or not, but the fact remains that the paper patched bullet hits 14 inches above the greaser on my 410 yard gong using the same sight setting. Maybe you need to use a little less theory and a little more applied trigger time and emperical testing. Hell, maybe you should be shooting my bullet.

I'd be interested in seeing what the change in sight settings from 328yds to 1000yds for both greased and patched bullets. I'd do it myself, but I don't shoot PPB.

These are all shot with the same load.

Sight settings:

pigs (328yds) - 0.52
turkeys (421yds) - 0.66
rams (547yds) - 0.88
800yd - 1.42
900yd - 1.61
1000yd - 1.82

mtn here's a sample from my notebook. Same basic shaped bullet same rifle , same velocity, same range same targets
Greasers Patched
800 1.62 1.50
600 1.2 1.12
530 .95 .9
As the range gets shorter the difference get's to be a bit smaller, but as the range gets longer we're back up to nearer 15 minutes difference in elevation.
Get ahold of some patched bullets roughly the same length and nose style as your greaser give them a work out. It is rather enlightening.Plus experience is never a bad thing..

Can you tell me, how do you guys like your greasers, hard, medium or soft?

I was thinking the same thing. that would be the real test.
Plus one would have to shoot them alternately in good steady wind conditions to see which is drifting off the target the furthest.

303 I use 20-1 for most everything,unless I've got some good wheelweight alloy.

20-1 for greasers, 16-1 for paper patched.

Paul

Thanks, I'll try to get some alloy that is in your ballpark. I had thought the paper patched bullets should be softer. Such thoughts make good reasons for asking...

Mike the alloy in paper patched bullets will depend largely on the nose shape and intended use. The now wildly popular "money" nose is a sharp pointy thing that really look like it would be more at home swaddled in a J4 jacket, so the need for hard alloy to keep it from nose slumping. More traditional bullet shapes can run from pure lead to what ever you feel like, altho if you get to hard of an alloy there may be some problems with good engraving of the rifling.

There's a lot of imponderables in the discussion here and while I don't have answers or specific insight into Gun "A" or bullet "B" there are several observations I'll pass along for whatever they might be worth.

Bullet drag cannot be viewed properly or solely in context of form and SD. There are a host of variables not on the table in the preceding discussion/arguments/personal assassinations etc. Among them are atmospheric factors, gyroscopic stability factor, velocity, bullet quality, density, barrel time and harmonics to name a few.

Form is pertinent certainly. Meplat diameter is a large factor in regulation of nose drag, that being the lions share of benefit provided by multiple caliber ogive radius. Multiples of ogive radius generally present smaller meplat diameters in inverse ratio. My readings of exterior ballistic publications indicate nose form accounts for as much as 80% of drag or perhaps more, dependent upon the aforementioned variables.

Shank drag, or that portion attributed to parasitic drag is a small component of drag, perhaps in the range of 2-3%. Base drag accounts for the remaining balance. Nose and base drag are induced drag issues.

Vaughn or McCoy, I forget which, discussed the influence of shank drag and possible effects of rifling engraving on drag contribution as insignificant due to their lying within boundary layer flow. Such aberrations are typically in the range of .004"-.006" in measure. It is not clear to me that grease groove contribution to increased drag is so limited. A reason for the thought is found in some but not all GG bullet forms that presents as a small increase of diameter at the break point of ogive and shank which is common to such bullets. I have one such bullet that minimizes this, probably as much as possible, yet the small change in diameter is still there. Aerodynamically it presents as a slightly larger cross sectional area and probably adds somewhat to vortex generation over the shank of the bullet. Small influence to be sure, but an influence none the less.



The bullets above are .403" diameter and weight ~350 grains when cast in pure lead. They behave as if they have a BC in the general range of .28 to .3 at an elevation of about 5,000' and MV of about 1,100 fps. They would probably do better as paper patch forms, but I would not speculate on degree.

If one were able to build a pair of bullets, one a PP form and the other a GG design with all other form features and weight equal I'd think there might be a valid basis for comparison. It can be done, closely, but by addition of the grease grooves, it is not possible to make them otherwise identical. Moot discussion as far as I'm concerned.

When one observes substantial vertical variation in POI in comparison with the different but similar bullets, there is no doubt it occurs as represented, but the question boils down to why. Drag? Yes, but how much? We do not have the answer and lacking sophisticated test equipment we will not find out definitively, and perhaps not even with such gear. The train load of variables involved put a lot of fog in the analysis picture. Barrel time/harmonics? Perhaps, but I don't know how that can be precisely measured.

Another point that grates on me a fair bit comes from illustrations of BC in these discussions. Not because the number cannot be identified as an average value, or specifically measured at a time and point in space, but because the value is so profoundly vulnerable to manipulation and measure. It is even more suspect when discussing bullets used in the velocity range common to BPCR bullets. They leave the barrel deep in the transonic velocity range, that being around .7-1.3 Mach or perhaps .8-1.2 Mach, depending on which guru one kneels to. Regardless, BPCR bullets do better in BC calculation as subsonic velocity than out of the muzzle. Roughly presented, the transonic velocity range is 850-1400 fps, +/-. So when the argument starts premised on a BC value which is illustrative, measured or guessed at, I need to ask what the parameters are for that value. Otherwise the discussion is without merit. An easy illustration of that is the variation in the value of a given gun/bullet/charge from ISA standard conditions at 5000' MSL and sea level.

My .02 cents on the topic and that's the last of my change.

Dan
I think you are trying to make this too complicated. All you need are two bullets with identical length and nose profile. that is what the argument is all about. Alloy could be identical or whatever shoots best for each bullet.
That's all.

Obviously the weight and dia would be slightly different.

Now which shoots with less windage and elevation change.
I'd sure like to know because it seems we have people with lots of experience on both side of the argument.
Brian

One other thing for consideration, a typical bore diameter patched bullet used in 45 caliber rifles will have a diameter of say .444, while the same length and style of grooved bullet in 45 caliber will begin life at .458. That difference in velocity alone will change the SD, the BC and the flight characteristics..And yes the slick will obturate up in diameter, but it will still be restricted to being smaller in final diameter than the grooved due to the paper shrouding it's ride down the barrel.