.308 win with plus 1 gas

[wade2big]

I’m going to have either a 20” or 22” .308win barrel chambered. Would moving to a plus one gas port location offer any advantage over a rifle length. I’m betting that this would still be reliable and most likely will smooth out the recoil impulse a bit. Does anyone have first hand experience?

 

[FredHammer]

I’m going to have either a 20” or 22” .308win barrel chambered. Would moving to a plus one gas port location offer any advantage over a rifle length. I’m betting that this would still be reliable and most likely will smooth out the recoil impulse a bit. Does anyone have first hand experience?

A rifle length tube on a 20" is plenty to keep it smooth. I personally wouldn't do any longer.

 

[TonyTheTiger]

I would absolutely try it, but I'm weird like that.

 

[nikerret]

Wade, what are you putting this on? I’m interested to see what you come up with.

 

[FredHammer]

I would absolutely try it, but I'm weird like that.

If that is the case, one needs to be ready to drill the gas port. It's not hard, just FYI.

 

[wade2big]

Wade, what are you putting this on? I’m interested to see what you come up with.

I have a SP10 builders kit built out with everything but the barrel.

 

[wade2big]

If that is the case, one needs to be ready to drill the gas port. It's not hard, just FYI.

I’ve shot 18” .308 with rifle length gas. I really don’t think a 20-22” with a plus one would have any issues. The 18” I shot had a H3 buffer and an adjustable gasblock tuned and the extracted brass still had extractor depressions on the rim of the case. I would have the gas port opened up on the side of caution from the start on this one. I think adjustable gas blocks or something comparable is necessary on large frames anyhow.

 

[FredHammer]

I’ve shot 18” .308 with rifle length gas. I really don’t think a 20-22” with a plus one would have any issues. The 18” I shot had a H3 buffer and an adjustable gasblock tuned and the extracted brass still had extractor depressions on the rim of the case. I would have the gas port opened up on the side of caution from the start on this one. I think adjustable gas blocks or something comparable is necessary on large frames anyhow.

Never know till test fire! I agree with the adj GBs. I've saved some over drilled gas ports with SA bleed off GBs.

 

[TonyTheTiger]

If that is the case, one needs to be ready to drill the gas port. It's not hard, just FYI.

Yup, been there done that quite a bit.

 

[nikerret]

I have a SP10 builders kit built out with everything but the barrel.

Awesome. I wanted an SP10, but they were impossible to find, when I was looking.

 

[wade2big]

Awesome. I wanted an SP10, but they were impossible to find, when I was looking.

I have a factory SP10 in 6.5cm. Excellent semi auto rifle.

 

[wade2big]

Never know till test fire! I agree with the adj GBs. I've saved some over drilled gas ports with SA bleed off GBs.

If shooting suppressed and unsuppressed they are necessary. Should have said that I suppose.

 

[smcfarland]

Sample size of 1 here, but I went from a 16 in carbine system to a proof 20” +2 CAMGAS and it is freaking smooth. 6.5cm with adj gas block, running suppressed. Recoil is less to me than a lot of overgassed 556 I’ve encountered.

 

[Bigtrucknut]

I order my barrels from X-Caliber. Their gas system/barrel length guidance is here: https://www.x-caliber.net/tech-info-2

I built a 24" barreled LR308 with a rifle +2 gas system that I absolutely enjoy shooting. It has the R+2 gas length, SLR adjustable gas block, VTLOR A5-length buffer tube and UBR stock, homemade (9.1 oz) stainless steel buffer, and a cut down A15 rifle buffer spring. I have the AGB tuned for hot (for an LR308) 168 grain handloads (dropping the brass at 3-4 o'clock) but it reliably shot Federal M80 147 grain ammo through it Friday without having to adjust anything. I attribute the ability to shoot a little hotter handloads to the additional delay in unlocking from the R+2 gas system and the heavy buffer. That's my theory and I'm sticking with it.

I'd say go for it -- R+1" on a 20" or +2" on anything longer.

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[TonyTheTiger]

I order my barrels from X-Caliber. Their gas system/barrel length guidance is here: https://www.x-caliber.net/tech-info-2

Holy conservative batman. Always remember those broad guidelines are designed for the lowest common denominator gun assembler and to keep manufacturers from having to field "why gun not go bang?" phone calls from arfcom types.
Anyone with half a brain can get away with way better setups than a mid length 20" barrel.

 

[msgriff]

For a 20" barrel, I can see the advantage if running mostly suppressed. The KAC SR-25 APR Mod2 runs a rifle+ gas system on a 20" 7.62/308.

 

[Mike_in_FL]

I’m going to have either a 20” or 22” .308win barrel chambered. Would moving to a plus one gas port location offer any advantage over a rifle length. I’m betting that this would still be reliable and most likely will smooth out the recoil impulse a bit. Does anyone have first hand experience?

I have a +2 20" X-Caliber that's pretty much always shot suppressed. So far it's my favorite .308 barrel and absolutely no problem with an AGB.