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  #1  
Old 05-20-2019, 03:17 PM
NickMarciano NickMarciano is offline
 
Join Date: Oct 2009
Location: Struthers,Ohio
Posts: 43
Default Puzzling problem with Match AR

I shot a high-power match yesterday with my Bushmaster AR. I've used this rifle for 5 years and have shot this year monthly. Yesterday
after the 5 sighter shots there were not hits ANYWHERE on the 200yrd. target. The next two stages were the same. Before the match I thoroughly cleaned the rifle as I did before other matches this year. I checked the rifle and found no loose sights(they were in the same setting as earlier matches).


Does anybody have any ideas about this? Has it happened to anybody? The gun has about 4000+ rounds through it.


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  #2  
Old 05-20-2019, 03:59 PM
Ryan V Ryan V is offline
 
Join Date: Jan 2010
Location: South West, MI
Posts: 841
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i had a bushmaster float tube come loose during a match, still on paper but groups opened up.
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  #3  
Old 05-20-2019, 06:08 PM
jsudduth jsudduth is offline
 
Join Date: Jul 2012
Location: Melbourne, FL
Posts: 338
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Quote:
Originally Posted by NickMarciano View Post
I shot a high-power match yesterday with my Bushmaster AR. I've used this rifle for 5 years and have shot this year monthly. Yesterday
after the 5 sighter shots there were not hits ANYWHERE on the 200yrd. target. The next two stages were the same. Before the match I thoroughly cleaned the rifle as I did before other matches this year. I checked the rifle and found no loose sights(they were in the same setting as earlier matches).


Does anybody have any ideas about this? Has it happened to anybody? The gun has about 4000+ rounds through it.


Nick10Ring@aol.com
Get to a range you can shoot it at about 25 yards. Put up a big target. Like a sheet of cardboard or something. Figure out where the shots are going then use that info to help diagnose the problem.

With the info you’ve presented it is almost impossible to offer assistance with diagnosing the issue.

Jim
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  #4  
Old 05-20-2019, 08:40 PM
champ0608 champ0608 is offline
 
Join Date: Sep 2010
Location: Arizona
Posts: 88
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I've had a few barrels that start ripping the jackets off bullets at higher round counts. Whether its a carbon ring, or a jagged gas port, or some other issue, I don't know, but that's been my experience. Especially bad with Hornady 75 bullets.
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  #5  
Old 05-20-2019, 09:10 PM
TLB TLB is online now
 
Join Date: Jul 2010
Location: Midwest
Posts: 2,097
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Similar issues with a M14 pattern rifle when the flash hider came loose..
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  #6  
Old 05-22-2019, 09:54 PM
lapriester lapriester is offline
 
Join Date: Oct 2009
Location: Cobb, N California
Posts: 16,361
Exclamation

It's very possible that the barrel nut has worked loose or possibly even cracked. If so, continuing to shoot it will do irreparable damage to the upper receiver and you'll be replacing it. It doesn't take long for a steel barrel extension to round out or damage an aluminum receiver. If everything else is tight that's about the only thing left that it could be. I've also seen a small piece of the rifling at the muzzle break off that caused the rifle to start shooting in a shotgun pattern all of a sudden of about 4-5 MOA. To check that will require removing the muzzle device. That damage can be very difficult to see. It took inspection with a magnifying glass to see the one mentioned above and only one land was chipped very slightly.
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  #7  
Old 05-22-2019, 11:34 PM
Whitpusmc Whitpusmc is offline
 
Join Date: Nov 2016
Location: Nashville, TN
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I second the barrel nut, I’ve had one work loose and the group went from tight to shotgun in 20 rounds.
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  #8  
Old 05-23-2019, 08:19 AM
ceresco ceresco is offline
 
Join Date: Oct 2009
Posts: 7,498
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How does a barrel nut work loose with the gas tube acting as a lock?? Good Shooting. .....
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  #9  
Old 05-23-2019, 08:23 AM
Whitpusmc Whitpusmc is offline
 
Join Date: Nov 2016
Location: Nashville, TN
Posts: 585
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There is some play in the width between the barrel nut points and the gas tube.

Needs to be to facilitate installation with proper torque, to prevent rubbing or possibly disturbing barrel harmonics (unsure of the last but you are trying to free float).

Mine loosened up just enough to allow a slight rotation and the group size went to hell.


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How does a barrel nut work loose with the gas tube acting as a lock?? Good Shooting. .....
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  #10  
Old 05-23-2019, 06:20 PM
Louisxllx Louisxllx is offline
 
Join Date: Oct 2009
Location: Austin, Texas
Posts: 249
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Once, I saw a barrel extension that came loose. That caused a "drop off" in accuracy.
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