All are 5.56/.223/.300Blk/etc.
Full milspec:
-8620 carrier
-Carpenter 158 bolt that has been high-pressure tested and magnetic particle inspected
-Grade 8 carrier key screws, properly torqued and staked twice
-Hard chrome lining inside the carrier bore and gas key
-Manganese phosphate finish
-Test-fired
Toolcraft with Ballistic Advantage logo $114.99
AO Precision (supplier for FN for US military M16A4 rifles) $159.99
Microbest (OEM manufacturer for many companies such as BCM and SOLGW) $159.99
Colt $199.99
"Milspec +":
-Same specs as above, except with a hard chrome finish instead of manganese phosphate
Microbest $199.99
Full milspec:
-8620 carrier
-Carpenter 158 bolt that has been high-pressure tested and magnetic particle inspected
-Grade 8 carrier key screws, properly torqued and staked twice
-Hard chrome lining inside the carrier bore and gas key
-Manganese phosphate finish
-Test-fired
Toolcraft with Ballistic Advantage logo $114.99
AO Precision (supplier for FN for US military M16A4 rifles) $159.99
Microbest (OEM manufacturer for many companies such as BCM and SOLGW) $159.99
Colt $199.99
"Milspec +":
-Same specs as above, except with a hard chrome finish instead of manganese phosphate
Microbest $199.99