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Posted: 7/19/2009 5:17:13 PM EDT
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Ok so I was at the range today to sight in my brand new build and i ran into a few problems. Now this rifle is going to be all CQB so i was sighting it in at 50 yards due to the better trajectory rather than 25. Ok so first off im running a flattop with Troy Industries BUIS "diamond head" and a normal FSB, F Marked. Now when i sighted her in at 50 my groups were on target but scattered so i got about a 6 inch MOA at 50, The chair i was sitting at was too short and clearly i wasnt even close to holding the rifle right way, so next batch of shots i corrected my chair, and fixed my posture, etc now the groups were still at a 6 inch MOA but down and to the right, so i cranked up my FSB 4 notches and still nothing all scattered some on target some weren't. The ammo i was using was 40 rounds of M855 not PD or xm the real deal and the other 30 rounds were IMI M855, After that i moved the target to 30 and still all my shots were scattered slightly closer but still not even close to the groups i wanted, not to mention my T-1 Micro when i was trying to co-witness it after my crappy groups kept turning off after 1 shot, idk if it was the shock or what but it turned off 3 times in a row then stayed on... HELP!
btw twist rate is 1/7, thanks -Dep |
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When sighting in, only use ammo from the same lot. Changing brands or even using ammo from a different lot from the same manufacturer can throw things off.
For future reference "MOA" is minute of angle. One minute of angle is roughly equivalent to 1 inch at 100 yards. The point being that a 6 inch group at 50 yards would be about 12 moa. But terminology aside, any time you're zeroing a rifle, make sure to use sandbags or some other method of anchoring that rifle down to the bench _good_ - otherwise, it's gonna be moving around and throwing everything off, so your shots will be all over the place and your adjustments will obviously not be correct. Also, I don't know how much you know about shooting, so make sure you're up on proper marksmanship basics like breathing and keeping your sight picture exactly the same, etc... as in, don't move your face forward/back/left/right in relation to where you had it on your last shot, etc. But you may know all that already. Just trying to think of some stuff that might help you. Not everyone will agree, but I have much better luck with smaller rear apertures than with big ones. Also, most people find that the longer sight radius of rifle length guns makes for easier aiming than the shorter radius of carbine length guns. Just some stuff to think about. Anyway, if you normally shoot much better groups with other rifles, check to see that your sights are tightened down good. Also, since it's a new build, make sure the barrel nut isn't coming loose. If you check all that, and shoot more groups using only one brand of ammo (preferably something known to be good accuracy wise), then you might just have a "not so good" barrel or something. Lots of things could be happening though, so take your time and work through all the possibilities. |
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Quoted:
When sighting in, only use ammo from the same lot. Changing brands or even using ammo from a different lot from the same manufacturer can throw things off. For future reference "MOA" is minute of angle. One minute of angle is roughly equivalent to 1 inch at 100 yards. The point being that a 6 inch group at 50 yards would be about 12 moa. But terminology aside, any time you're zeroing a rifle, make sure to use sandbags or some other method of anchoring that rifle down to the bench _good_ - otherwise, it's gonna be moving around and throwing everything off, so your shots will be all over the place and your adjustments will obviously not be correct. Also, I don't know how much you know about shooting, so make sure you're up on proper marksmanship basics like breathing and keeping your sight picture exactly the same, etc... as in, don't move your face forward/back/left/right in relation to where you had it on your last shot, etc. But you may know all that already. Just trying to think of some stuff that might help you. Not everyone will agree, but I have much better luck with smaller rear apertures than with big ones. Also, most people find that the longer sight radius of rifle length guns makes for easier aiming than the shorter radius of carbine length guns. Just some stuff to think about. Anyway, if you normally shoot much better groups with other rifles, check to see that your sights are tightened down good. Also, since it's a new build, make sure the barrel nut isn't coming loose. If you check all that, and shoot more groups using only one brand of ammo (preferably something known to be good accuracy wise), then you might just have a "not so good" barrel or something. Lots of things could be happening though, so take your time and work through all the possibilities. Ya kinda slipped on the MOA but that was my bad it should be 12 at 100, but like you said terminology aside, I didn't use a sand bag, i had 2 pieces of wood on top of each other with a towel under them, blocks didn't move or anything, used proper breathing techniques and sight picture, i get real good groups with my bushy which is just plain irons. but i honestly didn't know what to do when i had these groups, and as for using the same ammo ill try that next time instead of switching from M855 to IMI M855 |
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