Unchained Preppers
General Category => Security & Survival => Topic started by: Grudgie on March 12, 2013, 01:38:45 AM
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Wierd. Well did you scrub the shit out of the bore with a wire brush? See what comes out. Your average gun owner dosent know guns arent self cleaning. Too much fouling will cause accuracy issues. Maybe theres a point when it does this too.
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Many times, key holing is the result of barrel twist matched to bullet weight. My guess is your barrel twist is to slow, e.g. 1/12 or 1/13 rather than 1/8 or 1/9 that most AK 's are (I think).
Using a jag attached to a cleaning rod push a patch down the barrel to the breach. Mark the rod. Pull the rod out slowly till your mark on the rod has made one revolution. Then measure how much of the rod you pulled out to see how many inches in one turn your barrel is
If that doesn't make sense you may find on YT.
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I was thinking twist rate also, dude. My AK doesn't even keyhole with the heavy 154-grainer soft points (At least not that I've seen).
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You are probably going to have to send it to someone who can press out the old barrel and install a new one. It's going to be a bitch to fix.
Never seen a 7.62x39 keyhole. In the 5.45 guns it's caused by installing a barrel with the improper twist rate.
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Seems like the twist rate would have to be extremely slow for it to cause instant keyholing at such a close range. Its a .30 caliber light bullet. A .308win with 1/12 twist rate stays stable to 1000 yards and beyond with a heavier bullet. Its gotta be something else. Im not a ballistics expert by any means but something dosent sound right. Id clean the shit out of it. But maybe the barrels just shot out.
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Thanks for the tips so far guys. Here is an update. I tried your method Johnnymac and the jag failed to make a complete turn in the barrel. Infact, it only made a 50-60% rotation which would translate into something like a 1:30 twist. This could either be crud build up in the rifling grooves, shot out rifle grooves, or an out of spec twist rate which I doubt.
Tonight I will plug the barrel with a bullet and let it soak in straight hoppes no. 9 overnight.
If this doesn't work I will start looking into checking headspace and throat erosion. Also I'm going to do the twist rate test in a different barrel to make sure I am doing the test right.
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Based on terrain association, what is going to be your longest shot?
For example for me Urban, suburban and (my) rural is really close. If used effectively and properly then by definition the shotgun is probably my areas best weapon. What I'm getting at is. If the distance isn't to great in your area and you can still hit a torso at 100. Then don't waste time and money on it. Put the project on the back burner unless everything else is squared away.
However, not many people have terrain like mine lol. So I could be pissin into the wind here.
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Try the cleaning rod thing again with another patch added on, it could be that there just isn't enough contact but from the look of that crown I am suspecting that rifle has seen some use.
BTW great advice JMac +1karma for sure.
On a side note make sure that bullet you plug the barrel with gets put in the 'training only' pile.
Oh an stop it Reaver, you know better. Mission dictates equipment and lord only know where work will send you.
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Try the cleaning rod thing again with another patch added on, it could be that there just isn't enough contact but from the look of that crown I am suspecting that rifle has seen some use.
BTW great advice JMac +1karma for sure.
On a side note make sure that bullet you plug the barrel with gets put in the 'training only' pile.
Oh an stop it Reaver, you know better. Mission dictates equipment and lord only know where work will send you.
All I'm saying is. If it hits a torso at 100 yards. And other things need your time and money then make the other things happen first.
I personally would just off load it on some other Schmuck and let him deal with it. But I'm an asshole so it works for me. :P
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If used effectively and properly then by definition the shotgun is probably my areas best weapon.
[URL=http://www.smileyvault.co Shotgun = AR/AK worst nightmare. Stick your head up while i send 9 rounds at you at a time, i dare you. Or even at trade meets/close interactions gone bad, the shotguns taking 3 of the AR/AK with him.
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I'm a #4 buck man. 27 rounds at you at one time. :))
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I'm a #4 buck man. 27 rounds at you at one time. :))
Yeah i know you like that #4 buck ;D
i was thinking today. How hard would a 3.5" loaded with 21 #00 pellets be. Thats 2 5/8 ounces of hurt lol
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I bet none would keyhole ???
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I bet none would keyhole ???
lol i bet your right.
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I have some build experience in AKs, maybe I can chime in. Do you know the origin of the barrel? If it is Egyptian, the Maddi has two production classes, one for military (well made) and the other, low grade commercial. If it is a recent build, more than likely it is a US made barrel and judging by the results of your target, it is most likely to be the wrong twist rate for common 123 grain rounds witch is causing your problems or an over sized bore. You can find your twist rate by placing a piece of tape near the handle of a cleaning rod with a brush or mop installed on the rod. Push the rod in the barrel until the tape makes one complete revolution. At this point, mark the rod at the muzzle end with a sharpie then remove the rod from the barrel. Measure from the end of the brush or mop to the line you marked and this will give you your twist rate ( Ex. 1:7,7 being inches in length to complete one revolution). If the bore is oversize, you can measure with with a 32 cal lead ball(buck shot works well for this if that is all you have. Only one is needed) by slugging the bore and measuring with calipers. Use wood dowel rods and a mallet to push the ball through. It should come out to be .310-.311. If you are having excessive head space issues, you would have seen case head separation with a stuck case in the chamber by now. To be sure, I would pick up a no go gauge to test the head space. If it closes on the gauge, don't shoot the rifle anymore until it is fixed. I think the easiest fix if you want to shot with any real accuracy beyond 50 yards, is re-barreling it with a quality in spec barrel. Ak-builder produces his own and I would recommend his because he knows what he is doing and makes a good barrel and find a competent builder or gunsmith to do the work for you.