the-case-for-the-20-barreled-ar-15-rifle

The 5.56 NATO round was designed for max efficiency from a 20" barrel. Makes sense to use the barrel the round was designed for.
TSgt David L.,Lt Col Charlie Brown,
SSG Diane R., SPC Margaret Higgins,
CPT Jack Durish, Cpl Jeff N.,
LTC Charles Blake,SGT (Join to see),
SPC Gary Welch,Maj Robert Thornton,
CPL Douglas Chrysler,Maj Marty Hogan,
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MSgt Robert "Rock" Aldi,
PO1 John Johnson,MSgt David Hoffman,
COL Mikel J. Burroughs, CW5 Jack Cardwell,