Hey guys. I just bought the ST-15 16" mid length LE and since i figure ill be twiddling my thumbs for a few months waiting on it, i thought id start bulking up on ammo. I will probably end up getting russian steel cased rounds for cost sake, as i plan on burning a lot the first trip to the range i take. My question is, is the 5.56 significantly more accurate than the .223 out of the 1/7 twist or just slightly? .223 ammo is a little cheaper and easier to find in the correct number of bulk, so i was leaning that way. Plus my buddy shoots the .223 so we could split the cost of bulk ammo, but i dont want to sacrifice much accuracy. Anyone with experience willing to put in their two cents? Thanks

Most shooters will not see a difference in large difference in group sizes between 5.56 and .223. Especially not at most commercial ranges that only go out to 100 yards. The twist rate comes into play with the weight or grain of the bullets being fired, not so much the powder charge behind it or the processing of the case neck.

With a 1/7 twist, you can fire any 5.56 or .223 commercial factory loads with bullets weights of 55gr up to 75gr without trouble. If you go above or below that you are dealing with ammo for a different type of weapon system. Avoid exotic loads, reloads, or hand loaded ammo and you'll be good to go.

ok good to know. Thank you for the helpful information! i have to stock up on ammo now so i wont have to wait any longer to break it in when it comes