Home Forums Hunting & Shooting AR and Tactical Rifles I Need a Little Advice, Rifle vs Carbine Buffers and Springs

I did this before with a 20 inch Fulton Armory upper and a RRA lower, it was the one they advertised as being bought by the DEA but I cannot remember if it was carbine or Midlength gas. Mine worked fine. Try if before you do anything else, put one cartridge in it, fire if it locks back I would just use it also ejection should probably be 3-4:30 range.