PWC
Member
I'm outta' Pepsi and popcorn now....
I notice the example you give is in a rifle--which makes sense. The OP specified that this thread is about handgun loads. I think it's going to be very hard to seat a bullet so close to the lands in a handgun that the bullet deformation from a seating die results in it being jammed into the lands badly enough to raise the pressure to a dangerous level. Maybe if you are single loading rounds in a semi-auto which is kind of a pathological example. Obviously it can't happen in a revolver and would be difficult in a semi-auto since over-length rounds tend to not fit in the magazine.If the bullet is seated LESS deep, it's still an issue, because then the bullet jump to the rifling is shortened, and might even get the bullet jammming into the rifling if the originally intended jump was short to begin with.
If all those variables have really been addressed, what is causing the die to deform one bullet, but not another identical bullet? The same die applying the same force to the same place on a number of identical bullets will deform them all the same amount.And if you have first addressed all other variables, and still are getting very inconsistent seating, it iS the die insert shape that is the problem...
. . . The same die applying the same force to the same place on a number of identical bullets will deform them all the same amount.
So it's a matter of making sure the bullet is lined up before the die applies force?
If the bullet is lined up correctly, the bottom of the bullet is even and the mouth of the case isn't irregular, then that should prevent the bullet from rocking in practice--when it's actually being used to seat a bullet into the case. I'm not saying that the rocking is ideal; I just don't see how it could be a problem if everything else is taken care of properly.I could physically "rock" the bullet at the mouth of the insert.
Another rifle example....6.5 CM insert...
If the bullet is lined up correctly, the bottom of the bullet is even and the mouth of the case isn't irregular, then that should prevent the bullet from rocking in practice--when it's actually being used to seat a bullet into the case. I'm not saying that the rocking is ideal; I just don't see how it could be a problem if everything else is taken care of properly.Another rifle example.
So only an issue with JHP bullets that have inconsistent meplats--i.e. not identical bullets.
Without getting into whether or not the real problem is the die or whether it's a problem with poor quality control of bullets, or maybe some other factor, what kind of accuracy degradation is this intended to correct?
I did an experiment shooting different kinds of 9mm "budget/practice" ammo through one pistol onto one target awhile back. The test consisted of 10 rounds, 6 different kinds of ammo, 5 different brands represented, shot at 15 yards. Now, I didn't check the BTO on all that ammo, but considering all 6 of the loads used different bullets, loaded into different cases, likely using different powders, assembled by at least 5 different manufacturers, I'm willing to bet that there was a good bit of variation in just about every aspect of the cartridges one would care to measure. And yet all the bullets ended up hitting the 15yd target in a single 2" group.
That makes me skeptical that small variations in COAL in a single loading (same bullet/powder/case prep/primer/etc.) are going to cause any sort of practical degradation in handgun accuracy.
I'm outta' Pepsi and popcorn now....
Obviously it can't happen in a revolver and would be difficult in a semi-auto since over-length rounds tend to not fit in the magazine.
when I pulled the insert out of the die, and pushed a bullet gently into it (outside the die) until it "bottomed", I could physically "rock" the bullet at the mouth of the insert.
Excuse me while I put my boots on.I suppose it depends on your individual definition of "accuracy". To me, a 2" group at 15 yards would be awful.
Jim G
I would disagree with "naturally", but that's just me. I have a couple of pistols that will do that, but I have no desire to chase a .001" inch improvement in the CBTO of my ammo.When a handgun can deliver that kind of performance, you naturally want to push the limits further.
Jim G
So are you suggesting less talking and more (heck any) testing?In reading this thread, several thoughts come to mind.
1. The first thing to do is show that the small differences in OAL or BTO actually result in accuracy degradation in a handgun. If the gun or ammo can’t tell the difference, you’re wasting your time.
2. How to test it? Since you want to remove any and all influence from the shooter, at the least you would require a Ransom Rest. Even better, a barrel fixture device would be best. For this, you remove the barrel and place it in the device. This removes any tolerances issue produced by the gun (the barrel in the gun). Only then are you truly testing just the ammo (in that barrel).
3. How much of a difference in group size is enough to show a benefit in reducing tolerances? You can get a 3:1 difference in group size with the same ammo. (See the link below.)
4. How many shots for your test? Articles on the web show you get differences in group size even using the same ammo - with the gun fired in a Ransom Rest. This includes shooting 50-shot groups.
https://www.ssusa.org/articles/2021/2/17/accuracy-testing-how-many-shots-in-the-group
Based on this I think a lot of testing would be required to demonstrate that small differences in tolerances actually make a difference. And if it’s not tested properly or with enough ammo and in a proper test paradigm, you haven’t proven a thing.
So are you suggesting less talking and more (heck any) testing?
Articles on the web show you get differences in group size even using the same ammo - with the gun fired in a Ransom Rest.
1. The first thing to do is show that the small differences in OAL or BTO actually result in accuracy degradation in a handgun. If the gun or ammo can’t tell the difference, you’re wasting your time.
Were both targets shot with the optics equipped pistol?They still require human involvement in both mounting and use. You can learn a lot with them but one of the things you learn is that they are not perfect either.
I played with one for awhile, they are a fairly quick way to test A,B,C. For example I quickly found what this pistol preferred.
View attachment 1106280
Not going for point of aim as much as group size.
View attachment 1106282
It can be improved upon though, this is the one I made after using the Ransom, similar with just slight changes, you can see the difference on paper pretty easy, with the same load/firearm.
View attachment 1106283
Even better is to use an optics equipped pistol to ensure exact return, I even went so far as to make my own inserts to hold the firearms.
View attachment 1106284
Absolutely.
I'm assuming there were lots of gun blowups and injuries due to this dangerous issue... Right?All of the folks that used normal 230 RN OAL had sticking bullets, shorten the OAL by .030” and they run like a top.
OK! Now we have some kind of frame of reference for the kind of "problem" you're trying to correct and the kinds of guns you are talking about shooting. Yes, I suppose that if you're trying to nail down loads that will shoot under 4MOA with a pistol, some of what you are saying might make sense.I suppose it depends on your individual definition of "accuracy". To me, a 2" group at 15 yards would be awful. My SIG P210A shoots 3/4" groups at 25 yards.
Radical concept...1. The first thing to do is show that the small differences in OAL or BTO actually result in accuracy degradation in a handgun.