LiveLife
Member
Went with the KAK 9mm buffer, 5.4oz, standard carbine spring.I’ve been reading up on buffers and springs. I purchased a Spikes Tactical 8oz. buffer after reading a lot of suggestions that heavier buffers are better for these blowback rifles ... I figured with the 5.5 oz. bufffer and car spring that came with the rifle, the 8oz. bufffer, and XP spring, I’m bound to find a combo that works.
Ended up with 21.3 oz between buffer and bolt
Great!With a Spikes 8oz. buffer and car spring, it ran 100% with 115gr, 124gr, and 147gr (Freedom Munitions). Worked perfectly, recoil not bad.
PSA bolt weighs 14.9oz, so the total bolt + buffer weight = 22.9oz.
With carbine recoil spring, I found 19-22 oz combined weight of buffer and bolt produces more comfortable felt recoil. 16-18 oz combined weight produces harsher felt recoil.
PSA bolt 14.7 oz + PSA buffer 5.3 oz = 20 oz combined weight and produces comfortable felt recoil with various 9mm loads. Since 9mm carbines are blowback, for longest "in battery" time for more consistent chamber pressures (and not get case base bulged brass), use heaviest buffer that will reliably cycle the bolt.
With 20 oz combined weight, my 9mm carbines will cycle even lighter target loads (115 gr RMR FMJ with 4.6 gr W231/HP-38 or 4.1-4.2 gr Red Dot/Promo).
For reference:
- H1 buffer weighs 3.8 oz
- H2 buffer weighs 4.6 oz
- H3 buffer weighs 5.4 oz
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