I finally got to the range to try out my recently assembled PA10 - didn't go well.  It seemed accurate enough, but I had a slew of FTFs.  It didn't appear to be a gassing problem - I had a FTFs both from releasing a locked back bolt and holding the charging handle to let the bolt close slowly.   ALL FTFs were from the right side of the magazine, which is a Magpul SR-25.  The rifle cycled properly more often than not, but when a failure occurred, the bolt rides over the shell base once the bullet enters the chamber, crushing the shell. Ammo was Fiocchi RSD w/ 150gr.  Suggestions?

Change ammo....... many .308 ARs don't like cheaper ammo. Try 168gr from a quality company

Undergassed weak ammo?

Same magazine or various mags?

Not a gas problem - FTFs with hand-charging (1st round in mag) as well.  Same mag - I only had a single magazine with me.  The round tips up into the chamber, then the shell comes off of the bolt carrier and get crunched.  Not every time, but always from the right side of the magazine.  Left side rounds loaded 100%.

There were others with similar issues. One guy (YouTube) found that the ejector had a burr and was not compressing all the way in. I'd make sure yours does, first. Next, it's common that the extractors are way too tight. Take it off, remove an o-ring (they have two) and retry it.
Hope this helps!
Keep us posted!

I don't think the base of the shell gets a chance to get near the extractor.  The shell gets pushed forward in the mag, the bullet tips up into the chamber, then the carrier rides over the base of the shell.  The shell then gets crunched by the bolt, hitting it in the side (trying to fold the shell it in half).  The first shell I loaded was a FTF - I put two in the mag (top shell on right), had the bolt locked back, hit the bolt release and "squish".  Round came out looking like it had boomerang envy.  I also had the same thing http://www.ar15.com/forums/manageReply.html?a=modify&b=3&f=121&t=713809&r=7452706&page=1#happen in slow motion by holding the charging handle back and slowly allowing the bolt to close.  First AR-platform rifle out of no less than 20 that I've had any sort of feeding problem.

I read when researching a PA10, that the Gen 2 doesn't like PMags.

Really?  Can anyone confirm this?  What mags DO they like?

That may have been my post. Yes, it would not seat Pmags properly (it would smash the spine of the mag into the rear/lower of the mag well so hard it left gouges on the pmags). I solved it with some generous file work (beveling) of the lower/rear edge of the mag well and then touching it up with aluma-black (surprised myself with a job so clean it looked like it came from the factory that way!). I made a thread about it in the PSA industry section (with pics of the mod that resolved it).  HERE:

http://www.ar15.com/forums/t_2_301/282949_PA10-G2-Pmag-issue-RESOLVED-.html

But it may have been a "one off" receiver issue. I seem to have bad luck, as my latest (this time an Aero M5 lower) will not seat IMI mags (and barely holds on to Pmags). Unfortunately, the mag catch pocket is not drilled deep enough (catch not inserting into mag recess enough) and Aero refuses to acknowledge the issue (stating they have their "own" mag catch depth specs... even though they still use DPMS/SR25/LR-308 mags ). They also tested it with mags OTHER than the brand (IMI) that I told them falls out. So a big "F you" to me, I guess. So I'll have to resolve THAT issue, myself, as well (there's an entire thread on it in the Aero industry section). So.... it may just be me
Thread about THAT here:

http://www.ar15.com/forums/t_2_592/283123_M5e1-lower-dropping-mags.html

Thanks for the info - I'll look into it.

I had a couple FTFs but after a few rounds it started to shoot just fine. I was also using cheap ass steel case rounds so nothing quality in a pmag.

I have heard of another with the same issue. That person said they switched to IMI mags (I guess they sit slightly higher) and their PA10 worked fine. I'd also suggest Lancers, but dang their 308 mags are ridiculously expensive.

It seems odd, since the complete PA10s sold by PSA come with a PMAG.

I bought a gen 1 PTAC blem lower (I don't think you could get a lower with a worse internet commando rating than that) a year and a half ago and have had no issues with P mags or feeding.
the only issue I had was the extractor was way too tight and it would not ride over the rim of the new case, removed the o-rings and 1 of the springs, now it is 100%.

PSA had a Gen 1 complete rifle for sale last weekend - I was going to get it (they do look better than the Gen 2s) but wanted to test my Gen 2 first.  After having the feeding issues, I passed on the Gen 1.  Might grab one next time they come around.

I'm having a problem where the gun seems to chamber a round but the bolt stays locked into battery and has to be slightly mortared to extract the round. I removed one of the o rings and it seems to be a little easier to remove the bullet but still isn't working right. Is there a similar fix for the ejector? It moves freely but is VERY stiff.

Never mind. I tried better ammo and it seems that removing the o ring seems to have done the trick. At least well enough to wait for a trip to the range.