AR-308 20" Gas Block?

[Gargoyle]

Think I'll be good to go with a regular gas block running 20" rifle length tube on a 308 AR? 3:00 ejection? Or do I need to run an adjustable? Done it before on a 18" mid gas gun.

 

[Mark M.]

I believe 3 is ok, but no more than that

 

[Gargoyle]

OH sorry, I don't know if I have 3:00 ejection. Just ordered all the parts! LOL

 

[jepp2]

Think I'll be good to go with a regular gas block running 20" rifle length tube on a 308 AR? 3:00 ejection? Or do I need to run an adjustable

Do you know your gas port size? How about what weight BCG will you be running? Would think those 2 items could make or break the decision.

 

[DangerRanger]

All depends on the barrels port size. What barrel?

 

[Gargoyle]

All depends on the barrels port size. What barrel?

Ballistic Advantage

 

[Gargoyle]

Do you know your gas port size? How about what weight BCG will you be running? Would think those 2 items could make or break the decision.

You'd have to ask some crazy stuff like that! LOL Aero BCG.

 

[DangerRanger]

My last ballistic advantage barrel was gassed surprisingly well. Like very well. But being a more affordable manufacturer it may vary in consistency.

i would give it a shot with a regular one

 

[Gargoyle]

My last ballistic advantage barrel was gassed surprisingly well. Like very well. But being a more affordable manufacturer it may vary in consistency.

i would give it a shot with a regular one

10-4. Superlative arms adjustable gas block is but a click away. LOL

 

[PRECISIONWELDING01]

Superlative is my go to on all builds

 

[DiffEQ]

If you plan on using a silencer, an adjustable gas block will be helpful.
I have a Wilson Combat 20" 7mm-08 AR10 with rifle length / Odin adjustable gas block, and a BA 16" 308, mid-length with JP adjustable gas block.
No idea on port diameters.
Both have full mass bolts and rifle buffers.
The Odin gave me very little adjustablity, despite confirming proper gas block / port mating multiple times. I achieved my best adjustment by tweaking the buffer weights.
The JP block gave great adjustability. On a light 308 load, it gives 2:30 ejection, on maximum power, 4:30 ejection.
On full loads, if I were wide open, I'm sure my bolt would be slamming the end stops in the buffer tube.

 

[Pawnee Bill]

An adjustable gas block adjusted properly will ease the wear & tear on your cases.