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Posted: 11/25/2012 4:52:20 PM EDT
| Hey brothers of the AR15...I have a new Colt 6920 but having trouble getting it to zero. Using PMC 55 grain, and HSM 55 grain .223, and 62 grain military M855 in 5.56 all have the same problem. Using an Aimpoint 4S. The first few shots at 100 yards are within two inches. Then suddenly after about 15 shots the point of impact goes 6, 8, 10 inches high as the barrel gets hot. East and West stay relatively the same. I've tried using a Delta suppressor and same thing. My gut feeling is there is a problem with the barrel to receiver being torqued too much. I do not have the skill or know how to correct this so I would like your recommendations for a quality armourer or gunsmith who can fix this. Not sure of Colt's Warranty, I've owned it new for about 6 months. I might be wrong thinking it is the barrel and if you have other ideas I would like to read them. Best to all |
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Hey brothers of the AR15...I have a new Colt 6920 but having trouble getting it to zero. Using PMC 55 grain, and HSM 55 grain .223, and 62 grain military M855 in 5.56 all have the same problem. Using an Aimpoint 4S. The first few shots at 100 yards are within two inches. Then suddenly after about 15 shots the point of impact goes 6, 8, 10 inches high as the barrel gets hot. East and West stay relatively the same. I've tried using a Delta suppressor and same thing. My gut feeling is there is a problem with the barrel to receiver being torqued too much. I do not have the skill or know how to correct this so I would like your recommendations for a quality armourer or gunsmith who can fix this. Not sure of Colt's Warranty, I've owned it new for about 6 months. I might be wrong thinking it is the barrel and if you have other ideas I would like to read them. Best to all It sounds like we have the same exact problem, here is the thread that answered my questions, it might help you too. http://www.ar15.com/forums/t_3_66/591803_.html&page=1&anc=5727989#i5727989 |
| Yes it does sound similar. I tried calling Colt today. 45 minutes later and they still hadn't answered my call. I will try the cleaning idea. I have Sweets, but I think it has something to do with the barrel. Did you ever get your rifle to shoot after deep cleaning? |
| Yes I do have iron sights, but not using them. Mostly I use the Aimpoint 4s which is the most awesome sight I've ever used. I also have an Aimpoint pro, and Euotech, but the 4s is incredible. I've used the 4s on my M16A1 and gotten 3/4" groups at 100 yards so I really think it has something to do with the barrel to receiver. That is why I need a really good gunsmith to look at it. |
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Yes it does sound similar. I tried calling Colt today. 45 minutes later and they still hadn't answered my call. I will try the cleaning idea. I have Sweets, but I think it has something to do with the barrel. Did you ever get your rifle to shoot after deep cleaning? I just ordered the Sweets, but In the meantime I'll use some other bore cleaner and clean it a much as I can and will try it this weekend. |
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Question: these 15 or so rounds and then groups start climbing how fast between each round are you shooting . some rifles will shoot like this only because the point of impact changes as the barrel heats up . also try with open sights sometimes with optics as the upper rail gets warm it will move and so does your point of impact . a good cleaning and letting it cool down between shots would be a great place to start in trouble shooting :)
good luck Jim 
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Well I cleaned with Sweets several times,cleaned the chamber well. Then I shot with just a flash on the end. I got it to shoot pretty well first at 50 then 100 and finally at 7 yards.
At 7 yards all bullets were going into the same hole created by the first bullet. Then i put the can on, sighted it in at 50 then 100. Slowly. Then I tried shooting by resetting the trigger and firing fairly fast...the point of impact started climbing two inches on each shot when it was really hot to touch the suppresor. I then let it cool, went to seven yards again and shot several bullets through the same hole. Conclusion. The can is the culprit. As long as I keep the rate of fire somewhat slow it will be ok. For home defense, a can is a must, if you survive a home invasion and want to hear again. I did not try the iron sights but will on the next outing. |
| What kind of accuracy are you getting with the flash hider? I just got the same gun and wasnt thrilled about the accuracy. I am not very good with open sights st 100yrds. I was primariky shooting and trying to sightnin american eagle 55grain(black box frm walmart at 6.50ea is a deal!). I was 3moa or so. I need to miunt a scope to test it ut. I was hoping for 1-1.5 moa |
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Quoted:
What kind of accuracy are you getting with the flash hider? I just got the same gun and wasnt thrilled about the accuracy. I am not very good with open sights st 100yrds. I was primariky shooting and trying to sightnin american eagle 55grain(black box frm walmart at 6.50ea is a deal!). I was 3moa or so. I need to miunt a scope to test it ut. I was hoping for 1-1.5 moa Shooting MOA with irons, regardless of ammo, is very difficult. The target only looks so big on top of the post, so it is difficult to see any variation. If you want to know that your rifle can shoot MOA you typically need high quality match ammo, good glass, proper support, and adequate rest time for the barrel to cool. Just because your rifle may be capable of 1-1.5" at 100 yards doesn't mean you will ever shoot 1-1.5" at that distance. |
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Colt and FN produce their barrels to a standard of 3 MOA with factory ammo (M-193/M-855, depending on the twist).
Granted that most of these barrel will shoot better than this (around 2MOA for a 10 shot group), if you are looking for MOA or even Sub MOA out of any production barrel for a 10 shot group, God is going to have to really smile at you, and your hand loads, to achieve such. |
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