PPU brass, does it cause higher pressures?

[TNsailorman]

Better than weighing, cut a PPU case in two and then a R-P, Win., FC in two and you will see any difference in cas ewall thickness and this is problem what is going on with the higher pressure. Thicker walls = less internal capacity = higher pressure. Military 30-06 brass will run higher pressure than civilian 30-06 brass for the same reason. james

[Harter66]

PPU is also loaded and manufactured under CIP standards not SAAMI .

I've had no problems with it but it's in 30-30 and 45-70 so how much trouble can I get into . I did shoot some in 380 also with no issues .

As for life the 45-70 has 10 cycles on it with some of them driving a 255 to 2000 fps down to 500 and 535 subs and several Trapdoor to Cavalry loads with assorted 405 class bullets . The 30-30 has just been 2000-2200 fps 150-170 gr .

Next windfall I'm getting a few for the 6.5 Japanese .

[gumbo333]

I have reloaded PPU brass in several calibers, I don't strive for max loads and PPU has worked just as well as any other brand. But some factory loaded 308 ,150 gr I bought is hot. Big bang, big recoil, big muzzle flash. It likely his a bit different specs.

[Three44s]

It’s a handloading cardinal rule: When you change a component (or bullet seating depth) you treat it like a new load. Thus you drop back to a safe start level and build back up.

Do we do that religiously?

I know I have NOT done so all the time, at least not to the start anyway. The cost of components and lack of availability lately has me “puckered up”!

...... and so when we cut corners, we get stung every now and then.

I recall a custom carbine barrel in a Contender I bought used in .22 Hornet. I had just bought a whole bunch of new PPU brass. Loaded a start charge of Lil Gun and it was not my first dance with that powder and a different Hornet but MAN , did those primers get ugly!

I dropped my charges way low and never got out of the “starting blocks” with it, lower than prudent I thought.

I blamed the barrel ..... put it away, but maybe it’s the brass? Maybe it’s that barrel being tight and the brass being thicker. As I recall the PPU worked fine in another barrel (pistol) that shoots snake eyes.

I got some investigating to do!

Thank you Tazman for bring this to light!

Three44s

[tazman]

Okay. I went to my reloading room and tested both Remington and PPU bras for both weight and comparative volume. Here is where things get weird.

The PPU brass weighed LIGHTER than the Remington brass by 12-13 grains on the average. I weighed ten cases of each brand.

The PPU brass also appears to have a larger internal volume than the Remington brass. I tested this by filling a sized Remington case with spherical powder and pouring it into a sized PPU case. I poured it back and for a few times to make sure one didn't settle more than another and give a false appearance. In every instance the PPU brass had slightly more volume than the Remington brass.

Yet the PPU brass shows definite signs of higher pressure than the Remington brass with identical loadings in my rifles.
I can't figure this one out. Makes no sense to me.
The only thing I have not done is test them with a chronograph.

[TNsailorman]

Interesting to say the lest. The "experts" tell us that more volumn means less pressure with the same powder charge and that does seem reasonable to me. But your experiment say different. I have seen variable like this in my time in a chemical operation. Same amount of the same chemicals mixed would give slightly different result in the lab. Go figure.

[tazman]

I think I am going to do a full on test by loading a set of both types of brass identically in the same session and then shooting them over the chronograph through the same rifle to see if I can confirm this phenomenon.
It will take me a few days since the wife has plans for me the next couple of days.

[Mr Peabody]

I used some PPU 6.5x55 brass and it expanded a good deal more than our domestic brass did. It seemed to be softer than Hornady or Federal, I ended up pitching it.

[TNsailorman]

hummnn! the dreaded honey-do list, ay.

[gumbo333]

Well one thing you know for sure is........... nothing is for sure when it comes to reloading and components. Stay safe.

[flint45]

I use a lot of PPU brass I load it with less powder sometimes up to three grains less then other brass. It’s good stuff and lasts for more loading then other brands. My 22 hornet brass is longest lasting of all brands and one grain less in my favorite load over my other stuff. I load the hornet brass and 6.5x55 and .308, .303 in PPU brass.

[444ttd]

i use 8x57 ppu to reform a 9.3x57. i also use 7.65x53 argie ppu brass.

[Kuduking]

I had the exact same problem as the OP, using PPU .270 Winchester brass. My regular load in Wincehster brass, flattened primers and caused difficult bolt lift using PPU brass.

[MT Gianni]

Get a powder that flows like hourglass sand, AA 2 or 9. Measure the volume to the neck in an unfired case and compare to the same powder volume in Rem and WW. Then compare weights.

[35 Rem]

I wonder if you have a neck thickness issue here? Will a bullet easily fit in the neck of a fired case of either brand?

[trails4u]

when comparing internal volume....don't use powder, but rather use water. FL size but leave primer in case. put case on scale, zero the scale, add water until surface tension on the case neck. record tared weight. i normally average 5-10 cases to establish a baseline for any particular headstamp.

[wilecoyote]

my perplexity goes back to when the time comes to turning the necks. I have always feel a different behavior of the former combloc cases, therefore I have always suspected a different composition of the brass, and not in a positive sense. maybe I'm biased_

[braddock]

I load PPU cases for 357 mag, 223, 30/30 and 308 with no problems but I use Lovex powder and started from the Lovex start at loads.Personally thought the brass was harder than Rem, Federal and W-W but only because it "squeaks"at a higher frequency when trimming the outside of the neck.
The only real issue I've had has been with 223 where I experienced some "springback" in the neck diameter after neck sizing but sorted it by taking the decap pin outa the neck size die and giving the neck a squeeze when the boolit has been inserted to OAL.
FWIW prefer it over starline, or perhaps should say that starline is my least favorite brass.

[tazman]

I had purchased a large lot of these PPU 30-06 cases as once fired brass. They do all appear to be once fired. Very clean with no indications of ever having been reloaded.
I didn't and still don't want to "waste" them so I developed a load using the same powder, bullets, and primers but with a reduced charge for a Savage 110 varmint I have.
It turned out to be a real winner at about two grains below my regular load for my other rifle. This combination is producing one hole groups at 100 yards and around 1 to 1.5 inch groups at 200 yards. I confirmed this over three different range trips.
I am going to load up the entire batch of brass with this load and keep it for this specific rifle. It is significantly more accurate than any other load combination I have used in this rifle. Given the accuracy of the load, I really don't care about the velocity. The accuracy is far more important.