PPU brass, does it cause higher pressures?

[tazman]

I acquired a good sized batch of once fired PPU brass in 30-06. I normally use Remington and Winchester brass for my 168 match target loads.
I have fired hundreds of these with great results and no pressure signs other than very slight primer flattening. This load(H414) is already under max by about 1.5 grains.
The first time I loaded some of the PPU, I used the same data I used for my target load using Remington brass. It gave some over pressure signs in the PPU brass. Flattened primers and some cases were hard to extract. One primer opened at the edge a little.
I only fired four rounds. I pulled the remainder.
Today, I loaded some of the PPU with a different powder(IMR4895) and went 2 grains under the start load for that powder/bullet/cartridge combination.
These shot very accurately, extracted easily, and had slight flattening of the primers. I didn't have my chrono with me so couldn't test the speed.
Given the slight flattening, this still indicates that the pressures are running higher in this brass than the same load would in my regular brass.
Anyone here have any experience showing PPU brass tends to run higher pressures than other brass?

[panhed65]

I can't speak for the 06, but in my hornet, I have 3 brands of brass and the ppu is the heaviest of the 3, by a good bit too. heavy brass = thicker and less capacity, so should lead to higher pressure with the same powder charge. I can see the difference looking into the case at the powder, and had to cut back some loads so as not to compress.
Barry

[Kraschenbirn]

Agree with Panhed 65. My 7.62x54 Russian brass is about a 50/50 split between PPU and W-W; PPU is somewhat heavier and, more important, appears to have less volume. (Never did an actual measurement of the difference but, sometime back, when I was working up a load for some pulled JBs I noticed that a powder charge that filled a W-W case about halfway up the shoulder filled a PPU case right to the base of the neck.)

Bill

[CraigOK]

I like to use specific head stamps for a specific load. Helps me to keep things sorted. That being said you could compare how many grains of water each holds but im not sure if knowing the difference would allow one to make a scaled adjustment on the amount of powder or get close. I suppose the chrono would be the tool to fine tune.

[waco]

I had the same problems Taz with PPU in my 338 Lapua Magnum. Mid range loads with pressure signs and sticky extraction. I avoid the stuff like the plague now.

[tazman]

I had the same problems Taz with PPU in my 338 Lapua Magnum. Mid range loads with pressure signs and sticky extraction. I avoid the stuff like the plague now.

I got quite a bit of it in that batch. Enough that I really don't want to just dispose of it.
If I can make it work and use less powder in the process, I am fine with that.
It looks like that is what I will be doing.

[Gtek]

This is yet another story and caliber I have heard of with this brass along with primer pocket issues. I am not a metallurgist and did not stay at a Holiday Inn last night, but---. Is there or would there be a way to have some brass checked for content (somebody know somebody, wink wink) to check a batch of Win, Rem, Fed, etc. verses this "brass" for content.

[rbuck351]

With a different gun or different brass, you should start low and work up. Each component can cause lower or higher pressure and backing down for any new component is a good plan. I have been guilty of assuming a different component will make little difference with some unexpected results.

[Gtek]

I have personally witnessed a Marlin 336 with enough wear to be called well broke in have issues. Rem, Win, Hornady fired and cycled without issue. This brand very, very sticky extraction, all factory fodder- no reloads. Brass has not been reloaded so the test stopped there.

[Texas by God]

All that I can think of is that the Privi brass has a bit smaller internal volume. I have fired some PPU factory ammo in a Remington 710 that had symptoms like you describe, but months later it seemed normal in a Winchester m70. I’m currently using PPU brass in 22-250, .243, and 25-06 with no problems. Like you, I’m a grain or two below maximum in each case. I like PPU brass.

[farmbif]

interesting thread, back several years ago there were a few big stores that were selling ppu rifle brass on clearance, I probably have at least 10 bags I have yet to open in everything from 22 hornet to 270win, ive used some of the 30-30 but had not had problems with excess pressures but I don't make anywhere near max loads.

[farmbif]

one thing I have tried with ppu 270 was expanding it up to 35 whelen, every one I tried cracked, it expanded to 3006 die no problem but a lee 35 whelen die which is tapered cracked every one before getting close. funny thing is you can clearly see the heat discoloring on the brass where it was annealed. seems much more brittle than rem or win brass

[robg]

had no problem with ppu cases in 223 and 308 but ppu 45-70 brass is thinner than other brands .

[tazman]

Took the same loads out today as I did a month ago except this time I shot them in my match rifle.
No signs of pressure whatsoever. Nicely rounded edges on the primers. Easy extraction.
Accuracy was superb. I am talking 5 shot groups under 1.25 inches at 200 yards for 6 straight groups. It was windy so I wasn't expecting that.
One group, the wind stopped for a couple of minutes and I shot a .75 inch 5 shot group.
Seems this load has some possibilities. Only thing is it shot to a different point of impact but that is easily remedied with a scope adjustment.

[jim147]

Nice groups. I've had no problems with ppu brass in .222, 30-30, 303 Brit and I used to shoot their match ammo in my bull barrel .223.

[Jniedbalski]

I noticed using 223 ppu brass using varget that other brass when charged ,the powder was at the bottom of the neck. The ppu brass the same powder charge was in the middle of the neck. So it seems some of the ppu brass is thicker less internal space.

[Bigslug]

I think the issues are not with the Prvi brass, but that you exchanged a load that you had worked up in Remington brass. As I recall, it is very frequently some thinner/lighter/greater volume stuff.

Weigh your cases. The external dimensions are pretty much locked in by SAAMI, so heavier will equal smaller internal volume and higher pressures with the same charge.

[243winxb]

PPU brass tends to run higher pressures than other brass. Seen in 308 with starting load.

PPU 9mm Luger brass trim length can be longer then the SAAMI maximum of .754" May cause a problem in a match grade barrel with minimum headspace.

[MostlyLeverGuns]

Weigh your brass and compare weights, if all are trimmed to same length, the heavier brass will be thicker and have less capacity, causing higher pressure. I have found Win 308 brass to be 20 grains lighter than some LC and Lapua brass. Loads worked up using the Winchester brass show pressure signs in the LC brass. I've used PPU brass in the 303 Savage and 303 British with excellent results. I have uniformed primer pockets before loading (I do that to all my rifle brass) but I have not compared to other brands due to availability. When changing rifle brass I weigh new stuff for loads near the high end, not so much for boolits due to lower loading levels. Some brass may seem 'harder' than other, but this is really hard to test, only showing up in case life with 'hot' loads. Loading technique, annealing, other stuff can affect brass loading life as much as hardness.

[ebb]

Several years ago when we had another shortage with components I bought 243 PPU to make 260 remington out of. The only thing I could find I didn't like was the flash holes were off center. Now I am seeing off center flash holes in some domestic brass also.