Garron Posted November 20, 2016 Report Share Posted November 20, 2016 Hey all I need some guidance I just finished an ar308 build and I'm having pressure issues I'm using a Criterion barrel (m110 contour) 20in. Rifle length gas system and a ADK bolt... Bolt and chamber ext. DPMS compatible. I've got about 40 rounds through it. I started with some hand loads that 42.8 grains of varget fed brass and 175gr. Berger otm tactical bullets at 2.80 col I got ejector pin marks and cratered primers so I decided to use factory ammo and I used federal gold medal match 168gr at 2.80 in still got cratered primers and very slight ejector pin marks. I realize these are signs of over pressure but with fgmm 168's this shouldn't be happening do you have any ideas you can send my way .... Could this be a headspace issue...... Confused!!!! Quote Link to comment Share on other sites More sharing options...
392heminut Posted November 20, 2016 Report Share Posted November 20, 2016 (edited) Deleted Edited November 21, 2016 by 392heminut Quote Link to comment Share on other sites More sharing options...
shepp Posted November 20, 2016 Report Share Posted November 20, 2016 Welcome to the forum Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted November 20, 2016 Report Share Posted November 20, 2016 (edited) Welcome from Iowa, via Pensacola! I see those issues regularly with M118LR and FGMM 175 gr 7.62, doesn't bother me. I chalked it up to the firing pin hole being a touch oversized or the pin undersized and then being a touch oversized on the gas port with the heavier loads. Edited November 20, 2016 by jtallen83 Quote Link to comment Share on other sites More sharing options...
survivalshop Posted November 21, 2016 Report Share Posted November 21, 2016 How about some photo's of the spent Brass . Quote Link to comment Share on other sites More sharing options...
Garron Posted November 21, 2016 Author Report Share Posted November 21, 2016 will get some pics of brass but it's opening day here in western NC. Quote Link to comment Share on other sites More sharing options...
Garron Posted November 21, 2016 Author Report Share Posted November 21, 2016 Pic 1 42.2 gr Varget pic 2 a 168gr fgmm Quote Link to comment Share on other sites More sharing options...
survivalshop Posted November 21, 2016 Report Share Posted November 21, 2016 I think Jtallen83 is correct about the Bolts firing pin hole , it may be too large . You see a lot of this same issue with the new DPMS GII rifle , seems like they all do it . Primers don't look flattened , so its probably not high pressure sign . The Powder charge is with in load spec's , what is the COL of you hand loads , but if factory fodder is doing the same thing , its not your hand loads . Quote Link to comment Share on other sites More sharing options...
98Z5V Posted November 21, 2016 Report Share Posted November 21, 2016 Brass looks fine. You're gonna see an ejector swipe on almost every round. Those in your pics aren't a problem. Quote Link to comment Share on other sites More sharing options...
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