Everybody shooting 20"

But no 20 caliber?

Here's some that will work in an AR platform

TAC 20 (223 necked down 30 degree shoulder and longer neck)
20 Practical (223 necked down)
204 Ruger
20 Bobcat (223 Ackley necked down)
20 PPC (22PPC necked down)
20 Vartarg (221 Fireball necked down)
20 Slammer (222 Remington necked down)
20 TNT (17 Rem. necked up)
20 Terminator (222 Mag 30 degree shoulder necked up)
20 BR (6mm BR necked down)
20 Ferguson ACE (6mm BR 30 degree shoulder necked down)
20 Waldog (a shortened PPC and a 20/222 Mag. Improved 40 degree shoulder)


Oh, yeah here is my 20"....6x45