I’ve been shooting a lot of Federal AE 5.56/M193 55gr and it has been handling real well in my Mark 12 (18" 1:8 barrel) I zeroed my new scope with it at the last trip to the range and ended up with some very consistant tight groups at 100yds.
I recently picked up a few boxes of Winchester 5.56/855 62gr ‘penetrator’ ammo to try out. I was shooting it at the range today and all my shots were going far to the left (6-9").
I realize different rounds will have different characteristics but I was suprised that the windage would be off by that much. Would that be normal?
Very strange. I might expect to see a slight windage shift, but that sounds excessive.
I switch back and fourth between M855, M193, and .223 all the time with nothing like that. Typically I get elevation POI shifts, but no significant windage changes.
Unfortunately all I had was the 855 with me that day. I’ll definately bring some of both next time. Honestly I really like the M193 and the rifle seems to do well with it. I’ve just been trying different rounds to see what works best.
I know there is always a lot of heated debate going on about what is the best defensive round. I guess the 855 and M193 have their pros and cons. I guess the old handgun saying - the best defensive round is the one that you can consistantly hit your target with - holds true for our rifles as well.
One of your replies mentioned that maybe the 1:8 twist might not be enough for the 62 gr 855. I kind of thought it would have been enough.
Honestly, I don’t know, but I do hear that some 1:8s fail to stabilize 75gr or 77gr bullets, and those are typically made of lead, and the steel-core penetrator bullet might be as long as those.
