JP adjustable gas block??

[260shtr]

I recently purchased a upper with a JP barrel and adjustable gas block. After about 50 rounds it will not eject the fired round. On the gas block there is a allen head screw on the right side that was very loose.

My question is. Is the allen head screw like a simple valve (outdoor faucet) and by screwing it in will it create more pressure? I need to understand the operation of the adjustable gas block.

 

[bunsen27]

Re: JP adjustable gas block??

Righty-tighty, lefty-loosey

The JP adjustable gas block decreases the amount of gas when you tighten the allen screw. The answers you seek are on pg 2

http://www.jprifles.com/document_pdfs/JPGS5_140.pdf

 

[country888]

Re: JP adjustable gas block??

Bunsen answered your question, turn it in to the right to cut off the gas, or decrease it. Turn it out to the left to open it up, or increase it. You just have to play with it some to get it right. I close mine off, then open it alittle at a time shooting one round at a time til the bolt will lock back on a empty mag. Hope this helps!

 

[260shtr]

Re: JP adjustable gas block??

Bunsen

That's what I was looking for.

Thank you.

 

[Rogue1969]

Re: JP adjustable gas block??

The set screw allows you to tune the gas system to a specific load much like a water faucet. Screw in to reduce pressure and out to increase pressure. Remove the screw, lay it on a hard steel surface, and gently tap the thread area with a small hammer to slightly flatten the threads. Repeat this process on four sides. Re-install the set screw and tighten until it stops. Back out the screw approximately two turns. Test fire rifle with only one round in the magazine. Adjust the set screw in or out in 1/4 increments, until the bolt locks back on an empty magazine. Your brass should pile up at approximately 3 to 4 o'clock. Tighten set screw and note the number of turns in, until it stops. Remove set screw, apply small amount of Vibra-tite or medium strength loctite, and re-install screw to above noted number of turn out.