Will this 7.62x51 Malaysian ammo chamber in 308 PA10 from PSA?

I already have some 7.62x51 PPU that won't chamber....

It should and so should the PPU. Have you fired any ammo through the rifle yet or have you been unable to get any to fit?

Your headspace (or lack of it) would be suspect and the barrel/bolt combination needs to be checked. If you have gages you could check the headspace of the ammo. You could also check the dimensions of fired brass from your rifle.

I have been so disappointed with the quality of FMJ ammo, both 5.56mm and 7.62x51mm that I haven't purchased any in close to 30 years. Even when it fits it shoots like crap.

I doubt it's a headspace issue.  Just a very tight chamber and cheap 7.62 is not well known for being totally in spec.

Same stuff you see in lots of dpms 7.62.  Good ammo shoots very well, cheap surp and some commercial will bind up tight in the chamber.

It's snug on a 308 GO gauge, runs 308 Tula steel all day long. Will not chamber a 7.62x51 GO gauge, in which I've learned the 308 NOGO and 7.62x51 GO gauges are the same.

I took a chance and ordered a spare BCG from AIM, turns out after some reading and comparisons, it may be the same BCG PSA is using. It reacts the same as the original BCG on gauges.

I can measure the differences between the 308 and PPU stuff, you can see the marks on the PPU 7.62 cartridges when you try to chamber a few. It's not a dirty or rough chamber.

I guess it isn't worth the risk to buy more 7.62x51 of any type, maybe if this PA10 gets to the point it will chamber the PPU stuff reliably, who knows.

I had a case of 308 PPU that was tight at the shoulder in several rifles... I haven't bought any since.

Purchased 500 rounds of the Malaysian from aim.
It will chamber and fire, I got about 4" groups from 100 yards out of my PA10.

ISSUE: Ammo fails to eject about 95% of the time. It will extract from the chamber, but then it gets caught in the extractor and does not leave the receiver.

The gun functioned flawlessly with off the shelf hunting ammo. I tired multiple mags, Magpuls, and steel mags. Always had the same issue.
Rim issues on ammo?

Malaysian Ball wasn't exactly "NATO" standard and is best blasted out of rifles with generous chambers.

Specs:  .308 Winchester is shorter than 7.62x51 NATO. The simple, there's approximately a .003 difference in length, so a .308 "no-go" is a 7.63 "go" gauge.

I suppose if you were a reloader, you could pull it down, "bump" the cases in a .308 die, quick trim, and reload it with your favorite load.....years ago I member here had about a thousand rounds that wouldn't work because they were a whisker too long and that's what I did and it really wasn't a lot of work.  

I haven't taken my bolt(s) apart yet, but there is at least one youtube vid, and some discussion I read, that the two springs (inner/outer) under the extractor can cause it to 'run too tight' and the extractor wont let go of the brass at the right time, which can cause it to hang inside the receiver.
This is about general issues with ejecting, not specifically any particular ammo, but as stated above - it could be the Malaysian is just out of spec enough that it's one of the few times the stars align.

I'm not an expert in these things, these are my first two, I'm just passing on what I saw when people were discussing this same issue.
It might cause the issue, it might be coincidental, but it's one more thing to explore trying to figure out what might be causing the issues.

I haven't had my extractor(s) out to look, because that bastage is held in by the pin(s) that won't move no matter what, and I'm not going to screw with it overmuch yet as mine are running fine.
So far.

A strong possibility.
Looking to do that in the near future.

Got some of the Maylasian and it runs fine in two different Armalite AR10s
and of course in the FAL as well.

Surprisingly we did have to close the gas regulator two clicks on the FAL
so I guess this stuff is a tad weaker than the typical Winchester or Federal
M80 Ball that we normally feed the FAL.

The Brownells .308 AR mags would not feed the Maylay ammo into the Armalites
but Pmags would run it just fine.

Groups were not great, like 3 to 4 MOA. But we could still hit our 2/3 scale
IPSC steel target at 200 yds with the AR10s.

Thanks everyone!