Josh Smash said:
So, changing the buffer will change the feel(snap vs. push), but does not provide a distinct advantage like a comp or an adjustable block with low mass parts.
Is this right or am I still missing something?
Yes. As an example, the original M-16 had a rate of fire of 900 rounds per minute. That rate along with using the wrong ball powder caused major failure to eject from those rifles.
The fix was to add weight to the buffer, slowing it down to 700 rpm and changing the powder to slow down the impulse, allowing the brass to contract away from the chamber walls and extract. All of this takes place in microseconds, but timing does play a major issue in function.
Trickle this down to the AR-15, the same principles apply.
A comp redirects gas coming out the end of the barrel to counter the recoil, and eliminates barrel rise.
Bushmaster came out with a 3 Gun ready AR that had an issue with the comp actually causing the barrel to dip if I remember right instead of staying horizontal like is preferred.
A low mass BCG needs a tuned gas block to make it right. If I remember correctly, the grumpy ol gunsmith on here said that you open the block up until you get a good cycle, you need to open it up 1/2 more turn to make it reliable. Ammo is never 100% constant in pressure. It varies. The 1/2 turn makes it reliable. Reliable wins matches.