I had a DTI lightweight 16" barrel, and it functioned well for the 400 or so rounds I had. I liked the profile, which was maybe .700 to the GB, then .600 or so to the muzzle.
However don't let that detract you from moving forward on getting a quality barrel, the length you want.
I'd recommend getting the new enhanced Magpul buttpad for your CTR. It is great!
+1 for "I'll bet you don't notice much difference between the SA and FA carriers."
+1 for "you need a brake," at least a FSC556.
"Men speak of natural rights, but I challenge any one to show where in nature any rights existed or were recognized until there was established for their declaration and protection a duly promulgated body of corresponding laws." --Calvin Coolidge
Bookmarks