I can vouch for Simon's barrels. I have kicked butt at CQB matches (kicking my own butt, too) and felt super confident with his 12.5" barrel on my Armalite. Life is good! Never grouped that barrel at 100m with red dot SPARCII since the dot is too large, but I just love Simon's barrels! Not a single hitch during the build process!
Cheers and keep on helping them nooobs out there!!
Barney