fare . ▁ ▁Another ▁pione ering ▁weapon ▁in ▁this ▁role ▁was ▁the ▁Brow ning ▁Autom atic ▁R if le ▁( B AR ). ▁Int rodu ced ▁late ▁in ▁World ▁War ▁I , ▁it ▁remained ▁in ▁front - line ▁service ▁into ▁the ▁Vietnam ▁War . ▁Int ended ▁originally ▁as ▁an ▁automatic ▁rif le ▁capable ▁of ▁deliver ing ▁suppress ing ▁" walk ing ▁fire " ▁in ▁the ▁advance , ▁the ▁B AR ▁came ▁to ▁be ▁used ▁in ▁the ▁light ▁machine ▁gun ▁role . ▁During ▁World ▁War ▁II , ▁as ▁the ▁importance ▁of ▁having ▁a ▁source ▁of ▁mobile ▁automatic ▁fire ▁increased , ▁the ▁number ▁of ▁B AR s ▁in ▁a ▁unit ▁also ▁increased , ▁until ▁in ▁some ▁units ▁it ▁represented ▁ 1 ▁in ▁ 4 ▁of ▁the ▁weapons ▁present ▁in ▁a ▁squad . ▁During ▁its ▁long ▁service ▁in ▁the ▁US ▁military , ▁it ▁was ▁p iv otal ▁in ▁the ▁evolution ▁of ▁U . S . ▁fire team ▁tact ics ▁and ▁doctrine ▁that ▁continues ▁to ▁the ▁present ▁day . ▁ ▁Modern ▁squad ▁automatic ▁weapons ▁( such ▁as ▁the ▁R PK ▁and ▁L 8 6 ) ▁are ▁modified ▁assault ▁rif les ▁or ▁battle ▁rif les ▁( e . g . ▁F N ▁F AL ▁ 5 0 . 4 1 ▁and ▁M 1 4 A 1 ) ▁that ▁may ▁have ▁increased ▁am mun ition ▁capacity ▁and ▁heav ier ▁bar rel s ▁to ▁with stand ▁continued ▁fire ▁and ▁will ▁almost ▁always ▁have ▁a ▁b ip od . ▁In ▁the ▁case ▁of ▁some ▁assault ▁rif les , ▁such ▁as ▁the