caz41 Posted April 1, 2011 Share Posted April 1, 2011 I have a JP 18" .223 barrel with JP bolt and LMOS carrier on a BM upper receiver. The barrel and JP parts have at most 500 rounds through them. It all worked flawless from the start and then this past weekend when I went to unload a chambered round I was unable to pull the bolt back. I had to put some elbow grease to it and the round ejected. Working the bolt back and forth and I don't feel any resistance or anything grinding in there. When I chamber another round same thing happens. Upon inspecting the round after it kicks out there are some fairly deep gouges in the bullet. I know that the barrel lugs will put some minor scratches in a bullet but these are much deeper. It does this with MG reloads, Hornady reloads, XM193, etc... I case gauged the rounds, and the length is good also. I cleaned the hell out of the chamber and barrel lugs and it still does it. I looked with a light in the chamber and can't see anything that could be causing this. Here are some pictures. Any suggestions? Link to comment Share on other sites More sharing options...
Graham Smith Posted April 1, 2011 Share Posted April 1, 2011 (edited) Are these your own reloads? It sounds as if they have not been properly sized and trimmed. Have you checked them with a case gauge? Edited April 1, 2011 by Graham Smith Link to comment Share on other sites More sharing options...
caz41 Posted April 1, 2011 Author Share Posted April 1, 2011 The round pictured is federal xm193. It does it with factory and my reloads. I checked them all with a JP case gauge, all good there. Also length is good. Link to comment Share on other sites More sharing options...
benny hill Posted April 1, 2011 Share Posted April 1, 2011 Throat may be to short. Have it reamed about .020 Link to comment Share on other sites More sharing options...
caz41 Posted April 1, 2011 Author Share Posted April 1, 2011 This morning I was playing around with it, it again locked up on a chambered round. Again putting some elbow grease into it to open the bolt, when it did so the casing ejected, however the bullet stayed in. I am not sure exactly how far the bullet was in the chamber/barrel because the next round in the mag hit against it and may have pushed it further in. Link to comment Share on other sites More sharing options...
boomfab Posted April 1, 2011 Share Posted April 1, 2011 If it's pulling the bullet out of the case, your chamber needs work. Send it back to JP, they'll fix it. Link to comment Share on other sites More sharing options...
caz41 Posted April 1, 2011 Author Share Posted April 1, 2011 If it's pulling the bullet out of the case, your chamber needs work. Send it back to JP, they'll fix it. It only did it once so far. That is the plan at this point, no worries about them fixing it just wanted to see if there was something I was missing before I did so. Thanks. Link to comment Share on other sites More sharing options...
mpeltier Posted April 1, 2011 Share Posted April 1, 2011 My bet would be the ammo. If it was fine for the first 500 rds its doubtful the chamber changed. I would try some commercial ammo, not handloads or millsurplus. How does it function when shooting? Link to comment Share on other sites More sharing options...
caz41 Posted April 1, 2011 Author Share Posted April 1, 2011 My bet would be the ammo. If it was fine for the first 500 rds its doubtful the chamber changed. I would try some commercial ammo, not handloads or millsurplus. How does it function when shooting? It seems to function fine when shooting. The first 500 rds were with the same ammo (XM193 and handloads) and I did not have any problems during that time with that same type of ammo. Link to comment Share on other sites More sharing options...
M ammo Posted April 1, 2011 Share Posted April 1, 2011 My bet would be the ammo. If it was fine for the first 500 rds its doubtful the chamber changed. I would try some commercial ammo, not handloads or millsurplus. How does it function when shooting? It seems to function fine when shooting. The first 500 rds were with the same ammo (XM193 and handloads) and I did not have any problems during that time with that same type of ammo. If you are loading the ammo,,, are you using a Small base die???? I made the move to small base on all that I re-load,, test,, black marker the whole round,, put in in a mag, and chamber it in the gun,,, if it will fit,, pull it out,, then inspect the round,,, you will have your truth,, Jim Link to comment Share on other sites More sharing options...
BlueOvalBruin Posted April 1, 2011 Share Posted April 1, 2011 +1 about the throat being too short. Call JP. Link to comment Share on other sites More sharing options...
MILDOTS Posted April 2, 2011 Share Posted April 2, 2011 Is it clean? I just shot my rifle in a match a couple of weeks ago. I had nothing but problems. I ran a bore snake down the barrel and thought it was good enough. Turns out it wasn't. I cleaned the chamber and the bolt recess and lugs . Now it shoots like it always did. I got lazy and paid the price. Link to comment Share on other sites More sharing options...
caz41 Posted April 2, 2011 Author Share Posted April 2, 2011 My bet would be the ammo. If it was fine for the first 500 rds its doubtful the chamber changed. I would try some commercial ammo, not handloads or millsurplus. How does it function when shooting? It seems to function fine when shooting. The first 500 rds were with the same ammo (XM193 and handloads) and I did not have any problems during that time with that same type of ammo. If you are loading the ammo,,, are you using a Small base die???? I made the move to small base on all that I re-load,, test,, black marker the whole round,, put in in a mag, and chamber it in the gun,,, if it will fit,, pull it out,, then inspect the round,,, you will have your truth,, Jim I am using the dillon .223 dies. It does the same with factory loads and reloads. Also all the rounds pass the JP case gauge. Link to comment Share on other sites More sharing options...
caz41 Posted April 2, 2011 Author Share Posted April 2, 2011 Is it clean? I just shot my rifle in a match a couple of weeks ago. I had nothing but problems. I ran a bore snake down the barrel and thought it was good enough. Turns out it wasn't. I cleaned the chamber and the bolt recess and lugs . Now it shoots like it always did. I got lazy and paid the price. Clean enough to eat off it. Link to comment Share on other sites More sharing options...
Patrick Sweeney Posted April 2, 2011 Share Posted April 2, 2011 Stop torturing yourself, send it back to JP and let them pull out the heavy-duty inspection tools. Not a bad idea to send photos and sample knarfed rounds with the rifle. Link to comment Share on other sites More sharing options...
finch6013 Posted April 2, 2011 Share Posted April 2, 2011 Mine acts similar with xm193. But factory .223 chambers fine. Link to comment Share on other sites More sharing options...
caz41 Posted April 2, 2011 Author Share Posted April 2, 2011 Stop torturing yourself, send it back to JP and let them pull out the heavy-duty inspection tools. Not a bad idea to send photos and sample knarfed rounds with the rifle. Monday morning it goes to JP. Just hope it's back in time for Blue Ridge! Link to comment Share on other sites More sharing options...
kz45 Posted April 2, 2011 Share Posted April 2, 2011 I'm sure he can bring it to Blue Ridge Link to comment Share on other sites More sharing options...
whistlepig Posted April 7, 2011 Share Posted April 7, 2011 In ref to it firing fine, think about the mechanics. When u are chambering the round (reload or factory) it is chambering and the bolt is locking, so headspace is within specs. That is why the rounds are passing guage check. The issue is that the bullet, the projectile itself, is being jammed into the lands of the rifling. (what the previous poster was saying about the throat being short) and what u are seeing as marks at the ogive of the bullet. upon releasing the charging handle to first chamber a round the resistance of this is undetectable to you, and when the round is fired, it works as advertised, albeit with higher pressure. If you decide to maually unchamber a round, the bullet is resisting your pull, as it is "jammed" into the lands and the neck tension/crimp is pulling on the jammed bullet. If you are pulling the charging handle, the handle pulls the Bolt Carrier Assembly, which forces the bolt to rotate and unlock, then moves rearward and using the extractor, pulls on the rim of the case. The case is then pulling on the bullet. Either the case neck tension/crimp wins and the case comes out with bullet (and land marks) or the lands win and u get empty case and powder spillin every frickin where. Send it back. They will fixee. And send some sample bullets with marks. Link to comment Share on other sites More sharing options...
kamikaze1a Posted April 7, 2011 Share Posted April 7, 2011 Did you get that stuck bullet out? If you did, would be interested to see what it mic'd to above and below the cannelure... Link to comment Share on other sites More sharing options...
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