Accuracy

[TacticalSledgehammer]

Today while sighting my LMT defender upper in, I never got better than a 4" grouping at 50 yards. The barrel is in great shape. I'm thinking it is either ammo or my sights. I was shooting LC M193 55gr. The sights on it are magpul's gen 2 BUIS.

Is 4" typically expected at such a short distance? I plan to try other types of ammo as well (heavier than 55gr) All previous ARs I had were 1x9 (rifling)and this one is 1x7.

[Dustin Cantrell]

Are you shooting from a rest to reduce variables? 4" at 50 yards is horrible.

[Bulletdog]

I run the MBUS too. They are fairly "crude' even when you use the fine aperture. Try using a regular rifle scope with some magnification off of sand bags or a good rest to test the rifles accuracy. I wouldn't ordinarily run a set up like this on a "battle" rifle, but its a good way to test accuracy. I can get hits at 400 yards with a RDS with no magnification, but I'm still just sort of guessing and estimating. Put a 10 or 20 power rifle scope up there and I'm not guessing anymore.

Try running some other ammo through it too. Some guns prefer different ammo.

Another technique I employ is to have another good shooter print some groups for me. Someone who prints small groups with their own rifle and knows what they are doing. If they print significantly smaller groups than you, you'll know its the shooter and not the gun.

[markm]

As bad as those MBUS sights are, I'd still expect to get half that group size. That XM193 usually is capaple of 4MOA at least...

[ChrisCross]

I'd use (or borrow) a rest and take you out of the equation as much as possible. That way you can narrow it down to "user" error or "mechanical" error. This is NOT an attack on your shooting etc!! It's just how you would step by step test anything (narrow the amount of variables as much as possible).

Once you determine user vs mechanical you can remove a lot of possibilities and focus on what is really happening.

[LTMattyL]

How many rounds in the group to get your 4" measurement? Where was your group in relation to your point of aim?

[colthpd15]

Your groups should be at 2 inches or better at 50 years. Like Markm said the xm193 is a 4moa round out to 100 yards. But like other guys said try have another sgooter to see were his groups are printing.

[thopkins22]

And you've shot enough with other rifles to be sure it isn't you?

Try some other ammo. It's possible(though unlikely) that your XM(while safe,) is super reject and suitable for close range drills only.

[TacticalSledgehammer]

http://i680.photobucket.com/albums/vv164/Josh216_photos/ff0a22a683bd5d2cb943bcf3f538902f_zpscd0e54d5.jpg

I've been shooting for 20+ years. I was using a rest also. I've had other ARs in the past and so far this is the worst shooter. I haven't given up yet though. I plan to buy more ammo of a heavier weight.

[colthpd15]

LMT uppers are usually very accurate. I belive it could be the sights. Try putting on a magnified optic and see how it groups. But definitely change out those irons.

[markm]

Yeah... off that bench with some support, you should be seeing nearly 1"... no more than 2".... even with XM193

[8200rpm]

Are you using the SMALL aperature of the MBUS.

[Insta-Gator]

With the 1:7 twist you may need a heavier round. $0.02

If you are offended by anything in this post, then my efforts have been rewarded. :D Tapatalk+Autocorrect

[TacticalSledgehammer]

My phone is goofy. The damn thing will pick out a word that to my knowledge isn't a word and stick it in there every time.

I wasn't using the small ring when shooting, only the large. I was thinking the small one increases distance to 600?

[Iraqgunz]

Not true. Many of us shoot 55gr. with decent results. 50 or 100 shouldn't be that bad.


With the 1:7 twist you may need a heavier round. $0.02

If you are offended by anything in this post, then my efforts have been rewarded. :D Tapatalk+Autocorrect

[26 Inf]

I do believe that both apertures are on the same plain (or is it plane?) so the center of both apertures should be at the same location and theoretically should shoot to the same point of impact.

I'd use the smaller one.

[TacticalSledgehammer]

I bet a loose screw on the front sight base has a little something to do with it. Sorry for wasting space with this thread IG

[T2C]

That will do it.

[Bulletdog]

I bet a loose screw on the front sight base has a little something to do with it. Sorry for wasting space with this thread IG

You're not the first. You won't be the last. We've all had "those" moments. Glad its not your rifle!

[TacticalSledgehammer]

You're not the first. You won't be the last. We've all had "those" moments. Glad its not your rifle!

Yeah me too. I wish I had thought to check that at the range though.

[colthpd15]

If I am correct most standard front sights are 4moa so at 100 yards with xm193 55gr. you should have a 4 inch group and at 50 yards it should be 2 inch. unless you use match ammo then you should be able to have a little tighter group.

[shootist~]

Edit: Never mind.

[T2C]

Edit: Never mind.

I was thinking the same thing.

[colthpd15]

That is correct assuming if you take human error out of the equation.

[taliv]

a couple years ago, I bought an expensive rifle from one of the mfg that is very popular on this site. i got 4-8" groups at 50 yards with it. no keyholing either. i was shocked. tried all sorts of different factory ammo. nothing worked except oddly, my 80g SMK handloads that i used for 600 yard line in HP would go into the same hole at 50 yards. obviously, they wouldn't feed from mag and wasn't acceptable solution so... I sent the rifle back. they were able to reproduce my results. they checked all the usual culprits and couldn't find anything wrong with the barrel. but they replaced it anyway, tested it and sent it back to me. shoots fine now, but remains a mystery. heck, i don't even know how it's physically possible to get an 8" spread at 50. you could do better with a pasta noodle.


i figure i know plenty of 5 year olds who can keep better than 4" groups at 50 yards. it probably ain't shooter error. i wouldn't waste a lot of ammo trying to figure it out. get it rebarreled.

[rojocorsa]

Try different ammo. Something is not right. Keep us posted.

[TacticalSledgehammer]

Front sight worked its way loose. I think some of you missed that. It's the last post on the first page. Hopefully I'm good to go now.

[taliv]

wow, i did miss that. my apologies

[fido4x]

I have a Colt M4 with the MBUS rear sight. I shot a 2" group with some LC 5.56 tracer rounds. I'm a bit low and am waiting for another decent day to lower the front sight (standard iron front) and try again. I believe that I can get the grouping less than 2". I wish the rear sight had elevation adjustment. One day I'm sure I'll get some kind of an optic sight for it. For now, I'll just keep working with what I have.

[markm]

I have a Colt M4 with the MBUS rear sight. I shot a 2" group with some LC 5.56 tracer rounds.

Why zero with tracers? Those things do strainge stuff. Trident has a video where on just makes a left turn in mid flight. :confused:

[Arctic1]

I still think that is a riccochet.

[markm]

I still think that is a riccochet.

Have you seen the video? Riccochet is impossible as the bullet hadn't reached the target which is on the other side of the water.

It just banks low left and hits the water short of the target. My thought was transonic destabilization, but Trident didn't think that was it.

[The_Hammer_Man]

Have you seen the video? Riccochet is impossible as the bullet hadn't reached the target which is on the other side of the water.

It just banks low left and hits the water short of the target. My thought was transonic destabilization, but Trident didn't think that was it.

markm is correct the 64 gr tracer round is very well known for it's "radical" flight characteristics. Escpecially out of carbine length barrels.

I've seen them do shite that looks like it's out of a sci-fi special effects library. Left turns in mid flight, cork screwing, sometimes in the direction of the target, sometimes at right angles.

[GunnutAF]

TacticalSledgehammer
So did tightening the front site fix it? Can't leave us hanging like that man!:D

[TacticalSledgehammer]

wow, i did miss that. my apologies

No prob man

[TacticalSledgehammer]

TacticalSledgehammer
So did tightening the front site fix it? Can't leave us hanging like that man!:D

I haven't been to the range yet. I bet it did fix it though.

[fido4x]

Why zero with tracers? Those things do strainge stuff. Trident has a video where on just makes a left turn in mid flight. :confused:

Because it was what my lgs had in stock at the time. And it was too expensive at that but I picked up just 20 rounds for grins. They have since picked up some PMC and picked up 60 rounds to goof around with. Remember, I have only had this gun since Dec 2012 (3 days before the SHTF) and never had a prior need for 5.56. Trying to find it now is a daunting task unless you're rich and I'm not. I have a tough time with $1.00/round.