Gas Block Adjustment

[rchaas]

I have a new (to me) AR 15 that has an adjustable gas block. I am new to AR's in general, but trying to soak up as much info as possible. One thing I can't find much info about is how to setup and use an adjustable block.

Right now, mine is open "all the way" (per the previous owner) but the question is, what are indicators that would suggest that I need to make an adjustment in gas flow?

Thanks!
Robbie

 

[Wormydog1724]

Somebody once told me to close it way down, then get an empty mag with one round in the chamber, fire a round and see if the bolt locks back. If it doesn't, open it up a little and try again. Do this until the bolt locks back on an empty mag and you should be g2g. this is all second hand info from Wall.

 

[Chambers]

Somebody once told me to close it way down, then get an empty mag with one round in the chamber, fire a round and see if the bolt locks back. If it doesn't, open it up a little and try again. Do this until the bolt locks back on an empty mag

I go another quarter of a turn. People cut this way too close.

 

[Spiff]

Somebody once told me to close it way down, then get an empty mag with one round in the chamber, fire a round and see if the bolt locks back. If it doesn't, open it up a little and try again. Do this until the bolt locks back on an empty mag and you should be g2g. this is all second hand info from Wall.

Yep, this is correct. When you adjust the block, use the wimpiest ammo you anticipate shooting. Once the mag locks back, give it a little more gas (1/4ish turn more for JP block) for reliability when it's cold outside, someone puts mud in your rifle, you've done something stupid like not lube your rifle before a big match, etc.

 

[Wormydog1724]

I go another quarter of a turn. People cut this way too close.

That's what I forgot to say.

 

[rchaas]

Thanks guys!

What are the downsides from too much gas?

 

[drmitchgibson]

Thanks guys!

What are the downsides from too much gas?

Recoil

 

[jtischauser]

I would go an extra 1/2 turn. Better safe than sorry.

 

[DoctorJJ]

Usually you can start with it at least 2 1/2 turns from bottomed out. Then back it out more from there.

 

[rchaas]

Recoil

Makes sense...

Does an adjustable gas block require more cleaning/care than non-adjustable?

Thanks again, all!

 

[Spiff]

Makes sense...

Does an adjustable gas block require more cleaning/care than non-adjustable?

Thanks again, all!

Nope, they require the same: none. Lube the bcg and upper as normal, that's it.

 

[rchaas]

Awesome. Thanks again. Can't wait to get it to the range.