Wolf Gold keyholing in Colt M4

[Eurodriver]

I made this thread (https://www.m4carbine.net/showthread.php?174795-Federal-Fusion-MSR-shoots-like-bananas-in-my-M4-Carbine) a week ago about the terrible accuracy exhibited by my M4 Carbine using Federal Fusion MSR. Think 6"+ at 100 yards from a rest with an ACOG. It was bad.

I thought it was ammo related, because switching to Fusion (regular) shot a great group. It's all in the thread.

I did notice what seemed to be a keyhole, but dismissed it because it was a hanging target and assumed it was due to the target blowing around and the bullet not hitting the paper perpendicular to it. But today when I looked at the entire target pic showing a buddy, I noticed a very apparent keyhole.

http://i1328.photobucket.com/albums/w521/6234987u02/IMG_3665_zps11gkczck.jpg


Normally, I would dismiss it as cheap Russian ammo. But this is a new gun, I did no better than 6" groups with Fusion MSR through this gun, and I've been firing this same lot of Wolf Gold in 3 different AR15s that all shoot superbly. On the other hand, you can see from this image of a 5 shot group at 100 yards with the same rifle (http://i1328.photobucket.com/albums/w521/6234987u02/IMG_3664_zpsouplus3o.jpg) that it certainly can group Wolf Gold and from this image of a 5 shot group at 100 yards with Fusion (non MSR) ammo that it can shoot very well (http://i1328.photobucket.com/albums/w521/6234987u02/IMG_3660_zpsotxnarfl.jpg).

My question is: How do I narrow this down to the gun barrel or the ammo? What caused the keyholing? I shoot suppressed almost all of the time in one of my ARs, and have put at least 500 rounds of this case of ammo through my can with no issues but now I'm concerned that if it is ammo related I will have a baffle strike.

The Colt has <200 rounds through it, the muzzle device is tight and it all appears to be assembled properly.

[Mr blasty]

Possibly a burr on the gas port? It sounds like something could be loose or a bad barrel.

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[Mr blasty]

Have you checked the barrel nut torque?

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[Mechan1c]

The first 20 shots out of my 6920 were PMC bronze and 3 of those key holed. I was shooting at a paper plate just resting on a stump and I thought at first it was just the plate moving around. Looked just like yours. It's never done it since with a bunch of the same PMC Bronze, or AE223, PMC X-TAC, PMC M855, and Hornady 556 75 BTHP and some others I've forgot. It was odd and I think I kept it...If so I'll post it. At the time I just attributed it to it being new.

[SomeOtherGuy]

Normally, I would dismiss it as cheap Russian ammo.

If it's Wolf Gold, with the brass case, it's not Russian. It's either made in Taiwan (recent production) or Serbian Prvi Partizan (through 2013 or so). Either way it's decent ammo. Not FGMM or Hornady, but decent.


My question is: How do I narrow this down to the gun barrel or the ammo? What caused the keyholing? I shoot suppressed almost all of the time in one of my ARs, and have put at least 500 rounds of this case of ammo through my can with no issues but now I'm concerned that if it is ammo related I will have a baffle strike.
The Colt has <200 rounds through it, the muzzle device is tight and it all appears to be assembled properly.

How is the Wolf Gold shooting in the other AR? Have you tested it for accuracy?

On the 6920, try another quality ammo brand and see what your accuracy is and whether you have any visible keyholing. If three brands of ammo have problems, your barrel is the problem. If brand #3 shoots within expectations - no keyholing and probably 3 MOA or less depending on your shooting conditions - then I'd try the Wolf Gold in another known-good rifle.

[MegademiC]

The freaky thing is you have issues with random select ammo. Fusion good
MSR bad
Wolf bad
PMC good

Makes zero sense.

I would check everything.
Did you rest the gun on anything? Sure nothing was by the bore when you shot, and nothing between you and target?

[titsonritz]

How is the Wolf Gold shooting in the other AR? Have you tested it for accuracy?

On the 6920, try another quality ammo brand and see what your accuracy is and whether you have any visible keyholing. If three brands of ammo have problems, your barrel is the problem. If brand #3 shoots within expectations - no keyholing and probably 3 MOA or less depending on your shooting conditions - then I'd try the Wolf Gold in another known-good rifle.

It has been shooting fine in my 6920
http://i958.photobucket.com/albums/ae64/titsonritz/10%20shot%20group_zpsorbomt2e.jpg

[BillBond]

Sounds like the gun. Clean the barrel good and look down it with a bore light to see if you can see anything wrong.

[Eurodriver]

The freaky thing is you have issues with random select ammo. Fusion good
MSR bad
Wolf bad
PMC good

Makes zero sense.

I would check everything.
Did you rest the gun on anything? Sure nothing was by the bore when you shot, and nothing between you and target?

The only "rest" I used is pictured in the other thread. Rear sandbag and "grip pod" front rest. Muzzle device is tight, optic is tight (even removed it and reconfirmed), barrel is tight. No idea what's going on.



How is the Wolf Gold shooting in the other AR? Have you tested it for accuracy?

On the 6920, try another quality ammo brand and see what your accuracy is and whether you have any visible keyholing. If three brands of ammo have problems, your barrel is the problem. If brand #3 shoots within expectations - no keyholing and probably 3 MOA or less depending on your shooting conditions - then I'd try the Wolf Gold in another known-good rifle.

The Wolf Gold has shot great (same lot #) in at least 2 different AR15s. None have been "match grade" rifles, but a BCM 20", BCM 11.5" have done extremely well.

If you look at the pics in this thread, you'll see that I shot FGMM, Fusion, and Federal M855 (and in the other thread) Fusion MSR. The Fusion grouped extremely well. Nothing else keyholed, and all shot to "expected" accuracy except the Fusion MSR which shot like crap but did not keyhole.

Here is another quick group of the same lot of Wolf Gold I shot yesterday. I was testing my 300BLK sub loads so I did not shoot my M4 but for maybe 20 rounds. This was an 8 round group fired at 100 yards with a decent amount of speed. No keyholes, great group.

http://i1328.photobucket.com/albums/w521/6234987u02/IMG_3666_zpsmwrqdzxa.jpg

Here's an idea: The guy next to me was shooting a garbage brand AR15 with PMC bronze ammo at 50 yards. My target was at 100 yards. This was indoors and the lanes are fairly close together. Is it at all possible his rounds impacted his target and then keyholed into my target after the initial impact? The reasons I ask:

1) No other rounds have keyholed before or since. Wolf Gold hasn't keyholed in any other rifle, and this rifle hasn't key holed with Wolf Gold or any other brand since this one incident.

2) I shot this rifle out to 300 yards with decent accuracy about a month ago using Hornady Superperformance. (2.5 MOA using a 4x optic and shit rest) I think at 300 yards if a rifle was keyholing (and it was the rifle's fault) a 300 yard group would be unlikely.

3) I was shooting 5 round groups with the exception of the Fusion in the center in the pic in the OP. There are 4 M855 impacts, I'm guessing one went off the paper to the left. 5 FGMM impacts, yet 6 non-keyholed Wolf Gold impacts and 2 keyholes. I know that I shot 5 rounds at this target, but called the flyer all the way to the left, so I shot a sixth to confirm. I am 99% sure I did not fire 8 rounds at that target.

[Iraqgunz]

I think the stray Oswald bullet theory is possible, especially if you haven't had any other issues and the ammo was working fine in other ARs.

[Averageman]

[QUOTE=Eurodriver;2196295]
Here is another quick group of the same lot of Wolf Gold I shot yesterday. I was testing my 300BLK sub loads so I did not shoot my M4 but for maybe 20 rounds. This was an 8 round group fired at 100 yards with a decent amount of speed. No keyholes, great group.

2) I shot this rifle out to 300 yards with decent accuracy about a month ago using Hornady Superperformance. (2.5 MOA using a 4x optic and shit rest) I think at 300 yards if a rifle was keyholing (and it was the rifle's fault) a 300 yard group would be unlikely.
QUOTE]

I'm just thinking that if your rifle was at fault and causing the keyholing your group would likely be measured in feet rather than inches @ 300. Variables define issues, the fewer variables the easier it is to define the source of the problem.
It would appear two random variables appeared that were possiblly unrelated to your rifle, but none the less appeared on your target. It would definatly concern me, so I know your frustration.
There are many things you could/can do, but (as I don't have a dog in this fight and I know it would drive me bat shit krazy) I would find a clean range to shoot at on a weekday morning and do the whole test all over again.
Likely as not it was a random variable.

[JC5188]

The only "rest" I used is pictured in the other thread. Rear sandbag and "grip pod" front rest. Muzzle device is tight, optic is tight (even removed it and reconfirmed), barrel is tight. No idea what's going on.



The Wolf Gold has shot great (same lot #) in at least 2 different AR15s. None have been "match grade" rifles, but a BCM 20", BCM 11.5" have done extremely well.

If you look at the pics in this thread, you'll see that I shot FGMM, Fusion, and Federal M855 (and in the other thread) Fusion MSR. The Fusion grouped extremely well. Nothing else keyholed, and all shot to "expected" accuracy except the Fusion MSR which shot like crap but did not keyhole.

Here is another quick group of the same lot of Wolf Gold I shot yesterday. I was testing my 300BLK sub loads so I did not shoot my M4 but for maybe 20 rounds. This was an 8 round group fired at 100 yards with a decent amount of speed. No keyholes, great group.

http://i1328.photobucket.com/albums/w521/6234987u02/IMG_3666_zpsmwrqdzxa.jpg

Here's an idea: The guy next to me was shooting a garbage brand AR15 with PMC bronze ammo at 50 yards. My target was at 100 yards. This was indoors and the lanes are fairly close together. Is it at all possible his rounds impacted his target and then keyholed into my target after the initial impact? The reasons I ask:

1) No other rounds have keyholed before or since. Wolf Gold hasn't keyholed in any other rifle, and this rifle hasn't key holed with Wolf Gold or any other brand since this one incident.

2) I shot this rifle out to 300 yards with decent accuracy about a month ago using Hornady Superperformance. (2.5 MOA using a 4x optic and shit rest) I think at 300 yards if a rifle was keyholing (and it was the rifle's fault) a 300 yard group would be unlikely.

3) I was shooting 5 round groups with the exception of the Fusion in the center in the pic in the OP. There are 4 M855 impacts, I'm guessing one went off the paper to the left. 5 FGMM impacts, yet 6 non-keyholed Wolf Gold impacts and 2 keyholes. I know that I shot 5 rounds at this target, but called the flyer all the way to the left, so I shot a sixth to confirm. I am 99% sure I did not fire 8 rounds at that target.

Now that you mention this, I've had a couple of instances at an indoor range, where another shooters ammo "splash" came back towards the firing line and thru my target. It was actually copper jacket frags, but left a hole that could have been interpreted to be a keyhole.

I've been following this thread and had not considered this until now.


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[daddyusmaximus]

The Colt has <200 rounds through it, the muzzle device is tight and it all appears to be assembled properly.

How tight? I had a muzzle device on too tight once (way too tight) and it completely screwed up my gun, I was keyholing at 25 yards. A too tight device can compress the end of the barrel.

[Eurodriver]

I took it to the range today. Shot excellent. No idea what happened at the indoor range, but I'm going with the Oswald bullet theory.

it still doesn't like MSR. Shoots 2.5 MOA religiously with Wolf Gold. Better with Fusion.

Thanks for all the replies.

[cbx]

I took it to the range today. Shot excellent. No idea what happened at the indoor range, but I'm going with the Oswald bullet theory.

it still doesn't like MSR. Shoots 2.5 MOA religiously with Wolf Gold. Better with Fusion.

Thanks for all the replies.
Try to find some hpr 75 bthp ammo. I think you'll like it.