MOA Performance of M193 Ammo in a 14.5" Barrel


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Lets talk M193 ammo...

So I did a range day today, testing various ammo from my 14.5" AR. I semi-randomly grabbed 5 boxes of various ammo that I had, and set it out to do 5 strings of 10 shots of each type. 5 were done from a seated position at a shooting table, 5 were done from the same table with a rifle rest.

I am not a precision shooter, nor is this particular rig setup for precision. However I was shooting perhaps 1-2" groups, usually on the tighter end at 50 yards with a 4x optic. The target I was using did not have well enough define marks to actually see at 50 yards, so I dont really know if I was actually aiming at the same point every time. So probably the groups would have been tighter with a more distinct point of aim.

I ran a few strings, then suddenly shot a string that was a good 5-6"...then I ran another string and noticed the same problem. Looking at the boxes, I noticed both were M193, though from different manufacturers.

I ran the whole test again with a fresh target and more distinct aiming points, same results. Both strings with the M193 were HUGE, while all the rest were pretty tight.

You guys see the same kinds of results?

I plan to do this again with my "precision" setup and see how it performs.
What was the barrel twist? I suspect an older 1:12 or 1:9 would be better than a 1:7 with 55 gr. Generally a shorter barrel will have better accuracy at least at shorter ranges than a longer barrel. Lots of tests have been done by cutting barrels 1" at a time and test firing to prove that a shorter barrel is more stable and therefore more accurate with about 16" being optimal at 100 yards or less so I don't think it was the 14.5" barrel. My guess is it was the twist or just the particular barrel. My experience with M193 is 2-3" as 4x4 stated.


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As soon as you say different manufactures then all bets are off. While they are the “same” round by name each manufacture can use an different powder, primer, case, and event potentially projectile to make their M193. As such expecting any level of consistency across manufactures is pie in the sky kind of stuff.