Need help with accuracy please

[Bad_Karma]

My last two trips to the range have been frustrating to say the least. Since a picture is worth 1000 words I'll share my frustration with you :confused: :

http://i20.photobucket.com/albums/b231/BoulderTroll/DSCN272360.jpg

This 5 shot group was taken at 100 yards from a bench with the following:

Colt LE6920 (stock. No trigger/ accuracy work at all)
Winchester "white box" 223 rem 55 grain FMJ
Nightforce NXS 2.5-10x24 ZS
LaRue Tactical QD SPR mount

I've never had a hard time qualifying with a long gun for duty use, but at the same time I've never considered myself a "good" shot either. If the entire group was like those three in the middle I'd be completely satisfied. Those two shots up high in the 2 o'clock position weren't thrown. They felt just as good as the other three when I pulled the trigger.

I have no doubt about the quality of both the mount and the scope. Both are on loan for T&E and both companies have a superb reputation. So I'm just dumbfounded. This wasn't an isolated incident either. I tried the scope/ mount combo on my personal LE6920 as well and had pretty much the same thing happen, over and over again. I replaced and retightened the scope to the mount and the mount to the receivers countless times with no change.

The ONLY thing I can come up with it that it might be the "slop" between the upper and lower receivers on both of the two Colts. Like with most AR's, I can wiggle the upper reciever while it's attached to the lower reciever, even when a loaded mag is inserted. I'm wondering if I never noticed the problem before because I was supporting the forearm and the pistol grip at the same time. For these bench rest shots I was using the support hand to cup the stock into my shoulder, and resting the forearm of the rifles on the sandbags. So I was thinking maybe I'd get a decent group and then the slop between receivers would pitch the gun off slightly when fired. Could this be the reason?

Any help would be appreciated. At this point I'm just dumbfounded. Thanks.

[MassMark]

Have you tried with just irons? Perhaps try irons only at 25, 50 and 100 yards? The only other suggestions I have are physical and psychological. One, try and cure the play between your receiver and upper. I have never used an Accu-Wedge on my old Colt NM, but maybe? I have experienced what I call "5-shot-group-itis". If it's feeling good, I get antsy toward shot's 4 and 5 and blow it. Also, I've read some on Shoot-n-See targets, (I use them constantly). I have read that the reactive targets can be a hinderance when trying to sight in, (along the lines of paying too much attention to the splatter - even subconsciously). I would try again with either a paper plate, or just a good old fashioned 100-yard paper target. Good luck.

[TBomb]

I could be completely wrong about this, but since the optic is attached to the upper, and the barrel is attached to the upper, wherever the optic is looking when the trigger is pulled (assuming it is sighted in properly) is where the round is going to go. I might be missing something, but I wouldn't think that play between the upper and lower receiver would drastically hinder the accuracy of an AR due to that fact.

Are the two "flyers" the last shots of the group? First? Random?

[Bad_Karma]

Thanks for the info MassMark, I hadn't heard of the accu-wedge but I don't see how it could hurt. I'll look into getting one and see if it makes a difference.

As for the thought about the shoot'n'see effecting me I don't think thats it simply because at 100 yards I don't think I could even see them with the naked eye (of course I could through the scope though).

TBomb, I'm trying to remember which they were. I want to say like the second and 4th rounds, or something screwy like that. Definitely not together though. I see what you're saying about the scope being attached to the receiver at the time of firing. I wonder if the minimal amount of cant it changes in the upper and scope when it wiggles could be enough to throw them off that much...What I mean is the crosshairs could be dead center on the target but if the scope/ rifle is tilted it would make a difference as to where the bullet impacts (because of trajectory). I'm just not sure if that minute a difference in rifle cant could account for that big a difference at 100 yards.

[tkoglman]

The "slop" between the upper and lower receiver makes almost no difference. The scope is attached to the upper, the upper to the barrel. If the cross hairs are where they need to be when the rifle fires, the bullet will go where it should. Especially off a rest.

I would recommend finding a friend that you consider a "good" shot and let him shoot your set-up. Most of the time this will clear up whether it is operator error or not.

I would also try better ammo, but even WWB should shoot better than that.

[Bad_Karma]

I would also try better ammo, but even WWB should shoot better than that.

To be honest I don't think its the ammo. Three bullets less than 1/2 an inch from the "10" numbers is definitely a "group". If all 5 bullets had been evenly spread throughout that 3 to 4 inch gap, then I'd agree that it was probably shooter error, or bad ammo, or both. If the two flyers had been on oposite sides of the black I'd say that they were flyers. But look at how even they are in the same general area as eachother...thats what gets me.

I agree though, I will definitely have someone else try it as well. I could very well be the problem, but I don't think its with the aim. Those two shots are horrible, even for me :D . I think if I'm the problem it's with how I'm manipulating the gun, as in canting, etc.

[Bad_Karma]

Deleted because my brain is too tired to think right now and I wasn't making much sense. :D

[KevinB]

What sort of magazines? If it is the 2nd and 4th round consistently-- I would give some thought that the round may not be entering the chamber from that side with ease and is getting buggered up a bit.

[Bad_Karma]

What sort of magazines? If it is the 2nd and 4th round consistently-- I would give some thought that the round may not be entering the chamber from that side with ease and is getting buggered up a bit.

I'll have to check if it's those shots consistently. The mags I use for bench shooting are typically factory Colt 20 rounders.

[Charles]

Are all groups just like that one? Because unfortunately one group doesn't really mean anything. If every group was three and two, then there might be something up. However, your shooting a stock M4, regular hand guards (which means impact shift depending on how it's held), and "ball" ammo. I have shot a lot of M4's, and 2-3 inches is about the best your going to get with ball. Matter of fact, I would say the norm is closer to 4 inch groups at 100 yards. Shoot at least 2-3 ten shot groups. That will tell you something.

[threebanger]

My 2 cents.......proper follow through on your trigger will stop the right hand drift & breathing control will help with the elevation. Other than that get off the dang bench & get prone.

[wezalsgunsupply]

Personally we is my 2 cents. I dont think the upper and lower slop will throw two of like that. If you want to tighten it, forget the accu wedge. Its a band aid for a bullet wound. I think Jewel Pres. is the one that makes the tension pin that takes all slop out. But you have to have a allen wrench to take it out. Also maybe try some Tubbs final finish bullets thru it and polish your bore. It could be full of copper fouling. Can order these thru midway. Try some different ammo. I dont think its a mag issue. Could be getting some slop in the scope mount possibly. Let another shooter try it. Main thing is if you get pissed or aggrivated put it down for awhile. Good Luck Weez

[Kurt Reifert]

You got the same type of results with two different firearms?

That's interesting..

Scopes generally walk horizontal or vertical, but not both and a loose mount would have you all over the paper.

As Kevin B suggested, try a different mag. Doesn't matter if you're mag was a Colt. They get bent lips too.

I'd also have another shooter give it a go. If that doesn't work, try some different ammo.

[Low Drag]

Like others have said, the slop between upper and lower won't impact accuracy.

I'd say first get some other ammo. I've not been impressed with Win White Box 5.56.

Next work on the basics, and IMHO this is the most over looked of the basics. Body alignment. When trying to get "that group" be sure you're body is aligned properly. What I mean by that is to get into your best position on the bench and take a breath. Your sights/cross hair should move up and down through the bulls eye. Now close your eyes and relax, do the breathing exercise again with your eyes closed, even move back a bit to simulate recoil or have a buddy smack the front sight post a bit into your shoulder, again with your eyes closed.

Now open. Are you in alignment with the target? No? Then "scooch" into alignment and repeat. I don't care how good you are, if you have to "muscle" the sights onto the target you will never get a good group.

Next is that darn trigger control......

[taliv]

most factory ammo sucks. make friends with someone who has a runout gauge and an OAL gauge that measures from the ogive and see for yourself.

Your expectations are way out of line for your ammo/gun.

[HolyRoller]

I've never heard of using Final Finish on a service-weight chrome-lined barrel. I doubt it would do any good.

Runout is not a factor, so don't mess with ogive measurements.

With all due respect to KevinB, I don't see how a messed-up mag would cause such a deviation. If the bullets were getting seriously marred during chambering, I'd expect the bullets to go kind of randomly to different parts of the target.

It's definitely not lower/upper play. Accuwedges are a way of destroying $5 that could be better spent on 12 more rounds of ammo.

Here's a gem from 1SMALLJOHNSON at the Hide:

You guys want the secret? OK, here goes...

Just remember this:

A novice does not understand the fundamentals.
A tyro understands that there are fundamentals.
A budding shooter understands some of the fundamentals.
A good shooter uses and understands some of the fundamentals.
A great shooter knows all the fundamentals and uses them almost all of the time.
A champion knows all the fundamentals and never deviates from them.

Mr. Johnson is well qualified to speak on this, Mrs. Johnson even a bit more so.

If the ammo seems to be the problem, then try some groups with known fairly good ammo, such as Black Hills 77 OTM. But they also say, if you stay with the fundamentals, you never have to go back to them.

[Bad_Karma]

Thanks for all the great advice and suggestions, its what I was hoping for. Actually I was hoping someone knew the magic answer as to exactly why it happened, but I know thats not very realistic. :D

My plan is to do the following:

First I'm going to have a friend from work, who is an excellent shot, try the rifle with the same set-up, ammo and all, to see if its really just me (could very well be). Next we'll both use better ammo with it. Our duty rounds are Hornady TAP in 75 grain, so I'm hoping they should be pretty accurate. If the problem hasn't been solved by then I'll disaseble the scope from the mount and start again at square one.

[MassMark]

Good plan - I'd still try irons though....