1) Will the AR57 upper receiver fit on my existing lower receiver ?
A) The AR57 upper receiver will fit all Standard AR15/M16/M4 lower receivers.
It comes standard with a “carbine” buffer; for all “retractable” / “collapsible” / “carbine” stock lower receivers.
Please note: An additional buffer is available and required
for all standard “butt stock” / “rifle stock”/ “A2 type” stock lower receivers.
2) Howcome my AR57 Upper assembly will not run full auto ?
A) All AR57 Upper Assemblies come standard with a semi auto bolt that will
not engage any DIAS. A full auto bolt and buffer are available separately,
….. please see product catalog
3) Will the AR57 Upper receiver work with my existing fire control group ?
A) AR57 Upper assemblies will work with all standard MIL-SPEC fire control
groups … and most all “two stage” / after market / fire control groups.
Some exceptions may apply to other custom configurations.
4) Will the AR57 function with non-commercial / non-standard or handloaded
Warning: Using damaged, incorrect, non-standard or handloaded ammunition may result
in firearm failure or misfire. USE ONLY SAAMI or C.I.P. APPROVED AMMUNITION !
We can assume no liability nor warrant our products for incidents which occur through
the use of cartridges of nonstandard dimensions or which develop pressures in excess
of commercially available ammunition which has been loaded in accordance with
standards established by the Sporting Arms and Ammunition Manufacturers’ Institute
(SAAMI) or Commission Internationale Permanente (C.I.P.)
Brian Belko is a freelance writer and blogger. His primary areas of focus include the outdoors and shooting sports. In addition to his freelance work, Brian also writes for Wide Open Spaces and is on the Pro Staff at Military Hunting and Fishing. When he isn’t busy writing, Brian enjoys fishing farm ponds for bass and hitting the spring woods during turkey season.