Switching from RRA tube to Shockwave brace and Kak tube. Use same spring and buffer?

[N9zye]

I assembled a 300 Blackout AR type pistol. Shoots fine with Rock River Arms receiver extension assembly. I am switching from RRA tube to Shockwave brace and Kak tube. Can I use same spring and buffer? Should I buy the complete Shockwave blade kit? Thanks

[gaijin]

The RRA's buffer/spring will function, but likely not optimal.
Not knowing what components you've used, a 300 Blk, carbine length barrel is probably over gassed.
I don't know what the "complete Shockwave Blade kit" contains, but I'd be using an H3 or H2 buffer at minimum with a Sprinco blue or similar.

[N9zye]

The RRA's buffer/spring will function, but likely not optimal.
Not knowing what components you've used, a 300 Blk, carbine length barrel is probably over gassed.
I don't know what the "complete Shockwave Blade kit" contains, but I'd be using an H3 or H2 buffer at minimum with a Sprinco blue or similar.

My barrel is 9" Ballistic Advantage pistol length gas system. The Shockwave kit includes tube, spring, buffer, castle nut and brace.

[gaijin]

Short answer; I would prefer the KAK kit to the RRA's parts- they were engineered as pistol components.
I assume the RRA's buffer is carbine weight and is too light for 300 Blk (BCM advises using H3 buffer with their 300 Blk uppers from memory). I'm running a 10.3" BA barrel with an H2 (5.56) and 16" BA barrel with H3 in 300 Blk- rifle, but carbine length gas.
From experience, any pistol, buffer tube will "work" with the Blade brace, the KAK tube is designed around the brace and is easier to adjust for length.

Add this: I'm using a Geissle 42 braided springs in a couple AR pistols. I added two tungsten weights (from KAK) to "make" H3 buffers- as the Geissle 42 buffer weight is proprietary in diminsion and comes as as an "H" (H1).

[N9zye]

Thanks

[Todd.K]

Both use standard carbine springs and buffers. So you can use your buffer and spring. The buffer weight is totally separate, and can be changed either way.

I'm not a pistol brace expert but I see no reason you can't just put the brace on your RRA tube.

[N9zye]

My RRA tube measures 1.273 diameter. Shockwave info states the blade fits 1.25 maximum diameter.

[gaijin]

Your RRA buffer tube is obviously a “commercial”, not milspec tube.
Stands to reason, I’ve changed their carbine buffer tubes to milspec as they were commercial tubes.
Sounds like the easy solution is KAK’s kit with blade, buffer tube/buffer and spring.