Originally Posted by purehavoc
I wouldnt say its at .22 mag levels the difference between a 7.5" barrel and a 20", both .223 is roughly 430 fps at the barrel and roughly 600 fps at 80 M, sighted in at 50 yards still hits 10" steel plates at 100 yards . Now further than that its lost a ton of velocity and falls off pretty quick . I need to run it thru my chrono with some 5.56 and see how much difference there is between it and the standard .223 FMJ ammo on the velocity. Shortys have their special place of use and most cant justify the need or the want to spend the $200 for the stamp when they can get basically the same thing in a pistol with out jumping through the hooplah and the wait
I'm not really agreeing with the numbers you are posting here.
Optimally fragmentation occurs at velocities above 2700 fps.
Muzzle velocity for M193 55 gr fmj is in the 3200 fps range with a full length barrel.
430 fps is a really fast paintball.
250-1000+ for pellet guns.
230 gr fmj .45 acp shoots in about the 900 to 1000 fps depending on barrel length.
Um here you go....http://www.ar15.com/content/page.html?id=213
Once you go under 2700fps, fragmentation gets really spotty so for the most part you are just punching holes. But much deeper holes than a .22 magnum.