05-20-2011, 03:31 AM
turnbull,
You need a barrel extension with M4 feed ramps, or a standard upper. A standard barrel extension without M4 feed ramps with an M4 upper is a recipe for a jam-o-matic. BCM has standard uppers available with a flat top like the M4.
http://www.bravocompanyusa.com/Upper-Rec...0strip.htm
Les Baer and LaRue use standard barrel extensions after conducting high-speed camera testing and seeing that standard ramps work more reliably, according to their results.
The M4 feed ramps are really meant for full-auto M4's where the cyclic rate is much higher than the M16 since the gas system length is so much shorter. Basically, the M4 feed ramps were a band-aid that was applied to a problem encountered when high cyclic rates started stripping the next round out of the mag earlier than in semi-auto. Most current makers that consider themselves with the times use M4 feed ramps thinking they must be better since the military is doing it.
LRRPF52
You need a barrel extension with M4 feed ramps, or a standard upper. A standard barrel extension without M4 feed ramps with an M4 upper is a recipe for a jam-o-matic. BCM has standard uppers available with a flat top like the M4.
http://www.bravocompanyusa.com/Upper-Rec...0strip.htm
Les Baer and LaRue use standard barrel extensions after conducting high-speed camera testing and seeing that standard ramps work more reliably, according to their results.
The M4 feed ramps are really meant for full-auto M4's where the cyclic rate is much higher than the M16 since the gas system length is so much shorter. Basically, the M4 feed ramps were a band-aid that was applied to a problem encountered when high cyclic rates started stripping the next round out of the mag earlier than in semi-auto. Most current makers that consider themselves with the times use M4 feed ramps thinking they must be better since the military is doing it.
LRRPF52