I got one of IRG Colt 16 barrel deals a few weeks ago,it was cheap so i bought one,i was hoping i could get the barrel cut down to about 12",,is that some thing thats doable,there is about 6 inches in front of the gas block,after the step down in the barrel.any info would be appreciated,it's my first upper build from parts,going on a slick side upper,,no forward assist or door,


















































