Howdy;
Been playing with these for a while- built my first just prior to the Bush Ban ( AKA Brady) . Have not found bulk pack ammo of any wt to give what most of us expect as "good" accuracy,. though some aqre closer than others. That first AR I built was a plain A-2 configuration; Colt had come out with their A-3 upper ( removable carry handle ) H-Bar , which was noce, but too rich for my wallet at the time. Equipped mine with a 1:9 twist barrel; handled 55 gr just fine, which was all we saw back then, except for handloaders, who had a variety of lighter bullets on the whole. Does well enough with 62 gr "Green Tip", but not my fav in non-match factory bulk ammo . To contrast, my Never Ending Project AR, a heavy barreled varmint style configuration, with a 1:8 twist and a chamber described as something other than "match" .223, or even "Wylde", LOVES the Winchester Match load with 69gr HP bullets, making pretty , tiny cloverleaves at 100 yards from a sandbag rest. If I shoot Fed 62 gr Green tip bulk pack ( From Wally World ) , poor results; odd inexplicable flyers,to the extent that I first thought something was wrong with my rifle, like a cracked upper receiver at the barrel nut threads or some such. Not he case, just hates that ammo. A the ammo shoots "dirty" for me- far more cleaning effort required. I do have a kit, not yet assembled, which came with a 1:7 twist barrel. Cannot say I understand the widespread current use of the 1:7 twist on current guns, as it was brought out by the military ONLY to better stabilize the one, long, tracer round, at the expense of accuracy with others. YES, I do know that the fast twist is the cat's meow for heavy, long bullets that are used in Service Rifle competition- the ones that are so long when hand loaded that the rounds will not fit in the magazines , and must be single loaded by hand. THERE, the fast twist is proved to be right at home. Shoot 55 gr. ammo through that twist? I'm thinking over stabilized, at best, perhaps to the point where small imbalances in each bullet, inducing more yaw in flight, and actually ENLARGE groups with non match bullets, you know, the kind most people shoot.
Just my 0.02
