|
我看到有人说:Traditionally a "pencil", "lightweight", or "A1" were all terms for the same thing. A lightweight barrel in the same kind of design as the original or "A1" type rifles, with a .625" gas block or front sight base.
An "A2" or "Government" profile is the same as an A1 under the handguards, but then goes up in thickness to a .750 gas block seat, and a heavier weight (~.740) out to the muzzle. The "M4" profile is a government profile, but with a small thin area in the middle of the thicker section in front of the FSB to allow mounting of the M203 grenade launcher which was designed to mount on a 20" A1 profile barrel.
是不是可以认为gas block seat 是.750的就是粗管,.625就是铅笔管? |
|