• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Whats your tuning process for BOTH a JP buffer & adj gas block?

david8989

The Tactical Texan
Full Member
Minuteman
Aug 6, 2011
445
116
39
Bowie, TX
So I have a decent idea how to tune my JP standard weight buffer and adjustable gas block. But I'm curious of others processes. My method is to immediately drop one spring lighter in the buffer, then close the gas block entirely. Fire one round and look for the bolt to lock back. If it doesn't, then open the gas block one turn and repeat the process until the bolt finally does lock back. Once I have found this point, open the block another 1/2 turn for a functional safety factor. So how does your process compare? Also, I've always just gone off of feel for when to stop going lighter with my buffer spring. Is there a quantifiable way to determine when my buffer spring is too light? Thank you in advance for any insight.
 
  • Like
Reactions: bfoosh006
Does the rifle run reliably? Does it thrash your brass? If question 1 answers yes, and 2 answers no. Stop. Don’t over think it. That’s my method.
 
Does the rifle run reliably? Does it thrash your brass? If question 1 answers yes, and 2 answers no. Stop. Don’t over think it. That’s my method.
Lol, it runs good as is. I am just swapping loads to a much harder hitting 77g load from a moderate 55g and was thinking I wanted to tweak.
 
,,,if you are using an adjustable gas block, the AGB is what you would regulate the gas flow with, regardless of the buffer/buffer spring in use. When changing ammo type, your procedure of close AGB, 1 round, check, open AGB 1 click, repeat until lock back is sound. If moving to a heavier77gn bullet, I'd suggest just closing the AGB only a few clicks from your 55gn setting, then do the 1 round, repeat, until lock back occurs if only to save on components/ammo. More than likely you will find the AGB setting you currently have for the 55gn will also work with the 77gn load. just check the ejection pattern and brass after firing to see if it's slightly over-gassed...
 
  • Like
Reactions: david8989
My opinion is that the agb and buffer are related but for the most part do different things. Buffer (and total carrier mass) relate more to timing, recoil impulse and force to strip a new round. Agb is simply force directed to the carrier. For the most part you can use normal buffer weight and adjust gas block to lock back or get the ejection pattern you want and you're good. I've found that if you want to push the gun hard, you can use a very heavy buffer weight to keep the bolt locked up as long as possible and then adjust the gas block as normal to lock back. This will give more recoil but helps reduce the case head swipe. It all depends on what you're looking to do.