buffer weight

[montana]

The primary purpose of the different buffer weights are to correspond with the barrel mass to counter carrier-bounce in FULL or BURST Automatic fire modes.

The main reason for the added weight (H buffer) in the M4 was the adoption of the M855 bullet that had a different ogive than the M193 bullet that was causing feed malfunctions, not bolt bounce..

The original fix was the addition of feed ramps in the upper receiver.. Colt then added a tungsten weight to slow the carrier down to allow the magazine time to present the cartridge for proper feeding..Colt maintained the feed ramps as a redundancy for proper feeding and to keep the M4 TDP as Colt intellectual property when the government tried to claim ownership..

https://youtu.be/DYf-MLMODhA?si=zdMg_5I9DaHqUGYc&t=755