I understand the heavier the buffer the slower the rearward motion of the cycle. I find nothing regarding how a light buffer vs heavier buffers impacts the forward cycle motion and ultimately the impact of the bolt to barrel extension. Is there a trade-off? Slower rearward cycling sacrificed by a hard slam, outrunning a magazine spring, etc? I try to apply Newton's Third Law here but ........... Never claimed to be a boy genius.

Yesterday, I used the same newish buffer spring (basic JP), however, I switched from a carbine buffer, to an H buffer, ending with an H3 buffer. This was in a new 8.5" barrel pistol (5.56). The pistol came with the carbine buffer (unmarked and weight). Each test consisted of 2 rounds of basic 55gr FMJ box ammo. The bolt locked back with each buffer. Really didn't notice a difference in felt recoil, muzzle flip, all that stuff. The brass all landed approximately 4-6 ft away in an area perhaps of a 4ft or less diameter. Brass ejected from approx the 2:50 position to about 3:10/15 position. The only difference with the brass was that the H3 buffer did a harder, more direct launch of the brass though it landed in the same "group" area of brass.

Thanks