How to tell when a buffer or BCG is too light?

[Tim K]

I'm building a Valk on a 24" barrel, +2" gas. I got to thinking about what BCG and buffer to use. I'll be running a JP SCS, so I have 2 oz of adjustability available there. I also have a selection of JP BCG's to choose from.

JP Aluminum - 6oz
Jp Lmos - 9 oz
JP Standard - 11 oz
JP adjustable mass 12-14 oz

I understand the trade offs between weight, recoil, and reliability. My goal is to minimize recoil as this is a gamer gun. I will be using an adjustable gas block and running at TB 5" Ultra.

What I don't understand is how to know if the combination of buffer and BCG is too light. Aside from unreliability when dirty, is there some sign I should be looking for? Aside from the reliability concern, are there other concerns with going too light?

[SA Friday]

The easiest way to tell if the timing of the gun is too fast or too slow is ejection pattern. In general you want the brass to eject at the 3-4 oclock position and still lock open on an empty mag. I'm not sure you are going to really see the gamer performance from the JP gear on the Valkyrie cartridge. the main part that will be a must on the gun is an adjustable gas block. After that, The difference between more reliable parts like standard buffer systems in comparison to the benefit of the SCS is all a matter of scale. For example, the weight adjustment on the SCS in comparison to standard A4 buffers is smaller and the variety of springs give more flexibility. BUT it comes at a cost of reliability at lower round count.

Personally knowing the amount you shoot, I would recommend building the gun with more standard weighted BCG, buffers and springs but with a Superlative gas block and set the gun up to be reliable. Then try to translate it over to lighter parts at a later date if the movement in the gun is too much. With 223, the low mass BCG, SCS and adjustable gas block set up is pretty well hashed out. I built one a couple weeks ago for a shooter. It's straight up cheater gun. But with Valkyrie it's kind of a crap shoot, gas ports aren't as well established, system timing is as well hashed out. It's essentially a slightly lighter 6.8 SPC, but in a long distance gun.