No grouping to shots

[Jkline23]

Took the gun out to the range this weekend to see if I could correct what was wrong last weekend. AR-15 Stage Upper left hand, 20" bulls stainless 1:7 twist.

It has been shot 25 times prior to the past 2 weekends. It's groupings at 100 yards with 68gr were 4 rounds all touching on a windy day. The grouping with 50gr on the same windy day had three touching and one to the left 1/2". Needless to say it was pretty accurate. Last Saturday my first shot at 100 yards with a 55gr was dead center out of a cold bore. But everything since has been 4" high and 2" to the right with no grouping what so ever. I shot about 50 rounds and left seriously disappointed. Today I went back after cleaning the barrel and the results were the same with the 55gr and the 62gr. I ran 6 rounds of 68gr not grouping 1.5 high or more with one above center and one 2" to the left and one 2" to the right. Anybody have any ideas?

 

[Jet]

Welcome JKline

Your AR was shooting good with 68 and 50 gr bullets then accuracy started to go South with the 55 gr. There are a few reasons this could be happening and the folks on here might be better able to help you through it with some additional information. Some info to provide:

- Are you reloading of buying commercial stuff?
- Does your rifle have a 5.56 or 223 chamber?
- Are you using iron sights or an optic? If optic, how is it mounted?
- For each bullet weight, what components (powder, primer, case, etc) were used?
- What were your cases and loaded rounds overall length?
- How far off the lands (rifling) was each type off bullet?

There are other questions that could be asked but this will help folks narrow down the possibilities.

Jet

 

[Lapua40X]

Welcome JKline
... There are a few reasons this could be happening and the folks on here might be better able to help you through it with some additional information. Some info to provide:

Additionally, could you describe if you're shooting from a bench, using a rest and/or butt bag, off hand, etc.?
That's help .....

 

[Jkline23]

The first loads shot 68 and 50 were hand loads. All the 68 gr were hand loads match rounds. The 55 and 62 were factory rounds.

Optics is Burris 3x9.

It seems the first factory load sent the accuracy astray.

 

[Jkline23]

I was shooting off a bench with bags.

68s were hornady 22.0 gr 335
50s were Rem HP 23.5 gr H335

The factory were a Aguila 55 gr .223

After the first Aguila 55 gr. .223 which was dead center bullseye everything after including the hand load are off with not grouping what so ever.

I had a gentleman at the range run 3 Sierra 69 gr hand loads and his were off farther than my 68s just to verify it wasn't the shooter.

 

[BoydAllen]

How are you cleaning? If you picked up some fouling from the factory loads, it might have messed up the accuracy of your handloads. About that time, I would have been getting out my cleaning stuff, and then reshooting the handloads. If that doesn't work, I would look for something loose in the scope mounting, or if I didn't find anything there, I would switch scopes.

 

[Phil3]

First thing I would check is to make sure everything is tight. No lose optics, rail, missing screw, anything. The suddenness of this is what makes me thing something has happened to the gun. Did you clean it and possibly nick the crown? Or nick it just handling it? If the gun passes inspection, and if you can find it, try some Federal Gold Match. That stuff should shoot quite well. If it doesn't, back to the gun. Whose barrel? Chrome, stainless, chromemoly? You can try cleaning again, but if the cleaner requires time, be sure to provide it. What are the cases looking like? Good shooting ones vs the inaccurate ones. And do make sure the optic is not faulty. If the insides are moving relative to the outside, it will obviously be all over the place. Switch scopes or mount on a buddy's gun and see what happens.

Phil

 

[Jkline23]

No loose optics that was the first thing I checked.

The barrel is Stainless 1:7 twist. I contacted the GS who made the gun to see if he can take a look at it. The gentleman who also shot it said it was definitely not the optics.

My USMC sniper neighbor suggested something may have happened on that first factory load so be sure to give the barrel a good cleaning. He also said it was uncommon for the cold bore shot to be dead on but it was and as I stated everything from there on out have been high and to the right.

The hand loads were the first I shot today and was unable to get a grouping.

I am perplexed to say the least.

 

[Phil3]

2" left and 2" right, that is 4 MOA. How do you know that something is not amiss inside the scope? It would take very little to shift POI. While something may have happened with the first factory load, there is no evidence of any cause and effect. Something changed after that shot, but that does not mean that shot caused it. The cold bore shot can be off but it has to land somewhere. For the level of inaccuracy you are seeing, vs what it was to start with, I would think something is definitely quite amiss, beyond a dirty barrel. You have already cleaned it with no improvement, so that looks less likely as a culprit. If resting on bags, a loose front handguard could be a problem, as could be a loose anything (gas block, barrel nut).

If the gun was fired just 25 times prior this, then I assume it is quite new. ??? I honestly can not think of anything that factory ammo would do that would cause a problem like this. When you find the cause, please do let us know. In the meantime, if I think of anything, I will post it. I have an AR-15 as well.

Phil

 

[Jkline23]

Thank you Phil!

I will let you know when I find out the answer.

 

[jonbearman]

I have seen this happen to a almost new bushmaster varminter.At first he shot federal 55 fmj's and it grouped under a half an inch.He didnt break it in and got it hot several time's. Next he bought aguila ammo due to the cheaper price at the time.After a few shots it went from phenominal to run of the mill.He doesnt know how to really get it clean.It is now 2 years later and he is going to sell it due to the inaccuracy of the barrel.I wish I could scope it but my friend lent his scope out.I think the cheaper bullets may have partially shed a jacket,semi permanently plating the inside of the barrel near the throat area.If I can get it scoped,I could prove it.The cleaning rod always start's hard down the bore whether its clean or dirty.This is a theory and not a fact yet.I would JB the heck out of it to see what you get.I will bet it is coppered to death and normal cleaning wont remove all of the copper.

 

[Phil3]

If severe copper, then might as well go all out, with Warthog or Montana X-Treme Copper Killer 50BMG. If that doesn't take out any copper, and if copper still present, then the barrel may be done as I know of no other more potent way to get copper out. Short of the Outer's FoulOut system using electrolysis, which I think is discontinued as I hear the chemicals needed are no longer available.

Phil

 

[jonbearman]

If all else fails and there is something wrong with the barrel then buy a box of tubbs final finish ammo and see what it does or send it back under warranty.

 

[Jkline23]

Phil,

I spoke with a guy tonight who said to plug one end of the barrel and put a few drops of mercury in the other end and plug that end up as well. Let the barrel sit for three days and the fumes will remove any and all buildup in the barrel. But who has a few drops of mercury laying around?

 

[stinnett1981]

You need to take that scope off and put a different scope on it just to 100% rule out your scope isnt bad! Just because everything is tight doesnt mean your scope didnt go to crap and will not hold zero. I had the same exact problem! Had a .22lr and put a cheap $50 BSA scope on it. It was shooting under a inch at 50 yards for a month. One day it started hitting low and not grouping. I adjust scope and it would move again and not group. I asked all kinds of people and got lots of different answers. After a month I decided to go up to Cabelas and buy a different scope. I spent $225 on a Nikon Prostaff. Sure enough I was back to shooting under a inch at 50 yards! You gotta swap scopes out and prove it to yourself!

 

[47WillysGuy]

I had a problem with a Redfield 4X that wouldn't hold. Sent it to Redfield and they replaced some scope internals. Been good ever since. Don't blame the gun, until you rule out the scope.

 

[Phil3]

I believe the mercury bonds with lead, causing it to be removed. See this thread and post #8. There are some ideas about finding mercury, but it is dangerous.

http://www.thefirearmsforum.com/showthread.php?t=65482

I believe I may still have a bottle of the stuff. My wife's deceased father used to pan for gold and the mercury was used in that process. I remember it being in a corked bottle about 12+ oz. in size which is about 10.5 lbs or more. I also came across some in carburetor sticks used for measuring vacuum on 4 cylinder motorcycle engines. The warnings were clear, do NOT let the engine inhale any mercury, as the exhaust vapors would be very toxic.

As far your rifle, I would very much encourage you to try a different scope before trying to chase down potential problems in the gun. Do you know someone willing to let you try their optics? Barrel fouling is gradual, and find it very hard that after a single shot, the fouling now jumps to a degree that the accuracy falls off so severely. Your accuracy went to hell all of a sudden, and I personally think something fairly notable failed or changed in that time, such as broken scope, cracked screw, etc. I could be wrong of course, but you already tried cleaning and that had no impact at all. I rather doubt more cleaning will change that. You yet may prove me wrong, and if so, would very much like to hear what the problem is.

Phil

Phil,

I spoke with a guy tonight who said to plug one end of the barrel and put a few drops of mercury in the other end and plug that end up as well. Let the barrel sit for three days and the fumes will remove any and all buildup in the barrel. But who has a few drops of mercury laying around?