.308 gas gun load

[Billiam1211]

Just a question, are you shooting any of these suppressed? Because whenever I shoot any loads much lighter than the ones you posted, I get some pressure signs early on. I use LC and IMI 7.62 match brass. I have a batch of LC-LR but never wanted to waste it on a gas gun. When I shoot those same loads suppressed, I cannot use the brass again. ( I get flat primers, expanded case heads, and primer pockets are blown out after one firing) I shoot an LMT MWS with 18" SS barrel. It's a precise gun, sub MOA with lighter loads, but I'm getting flat primers at 4 grains below what most are shooting. I've used Varget, XBR, and 4064. Now, I've never seen ejector swipes, but the loosening primer pockets especially suppressed is what's worrying me. (I've also use the 16" CL barrel and I have the dual-ejector bolt and same symptoms) Looks like my chamber is cut fairly loose. Should I up the load somewhat and maybe get better sealing? Also, this rifle is overgassed so that may be why it beats up my brass.
Thanks,

I run a home built 308 Win gas gun and had similar issues with pressure. I used 175gr SMK and with Varget couldn't go over 42 grains, IMR 4064 gave me pressure signs at 42.6gr, and H4895 ran into pressure at 41.5gr.

I ended up settling on 43gr of Reloader 15 which gets me 2,700 fps with the 175gr SMK and no pressure signs. It's also a super accurate load that has been sub-moa out to 600 yards.

 

[LANCER]

I run a home built 308 Win gas gun and had similar issues with pressure. I used 175gr SMK and with Varget couldn't go over 42 grains, IMR 4064 gave me pressure signs at 42.6gr, and H4895 ran into pressure at 41.5gr.

I ended up settling on 43gr of Reloader 15 which gets me 2,700 fps with the 175gr SMK and no pressure signs. It's also a super accurate load that has been sub-moa out to 600 yards.

I have a pound of RL15 I have never used it so will try it. Thanks for the suggestion. Gas gun loads are very sensitive to pressures it seems.

 

[LANCER]

I start at 41.5 of varget and work up for 168's on the sass, elfster has a good thread on this for his LMT in the semi auto section.

I'm having a hard time finding the thread you mention, as I too, have an LMT and trying to find a good load for it. I laugh at all these people stuffing 44 grains of varget under 175SMK and actually being able to reuse their brass. I blow out primer pockets at anything higher than 42 grains, even with 168's. I lose my brass because primer pockets are shot after 1 firing. If shooting suppressed, forget it. I've done away with Varget on gas guns as the port pressures are too high. 4064 is a good powder, as is 8208xbr for 168's, but one must stay several grains below book .308 values when loading for gas guns. Not sure how you guys are able to reuse your brass in gassers at those load levels.

 

[elfster1234]

As for my 308 LMT that had a 1:10 twist, 168’s all day long. It especially liked 168 amax and varget.

I’ve always said this about firearm, just because a Particular lord shoots well in my LMT 20” AR doesn’t mean it will shoot well in your LMT 20” AR. Firearms are just like ex girlfriends, they can be real pain in the ass. Only way is to do load development. My current method is to shoot an array of bullets that the rifle simply likes to shoot before even doing powder drops, then move to powder drops on which ever bullet performs best, then maybe jumps.

Also, if you’re shooting under 600 yards, shooting the HOTEST load isn’t always the most accurate load and only testing barrel harmonics with different powder drops will tell ya the true story. My 20” LMT had a crazy accurate node of 41.8 varget with 168 amax with lake city brass and CCI 200 primers