Author Topic: question on gun jam  (Read 3794 times)

79takjr

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question on gun jam
« on: January 20, 2009, 06:49:57 AM »
So I went to the range the other day with a batch of .223 reloaded on  Dillon 550.  Hodgdon H335 powder, 55grain projectile FMJ.

I fired about five rounds and all was well, group wasnt great, but acceptable, next round misfed and had a hung round.  Cleared the round and tried to continue to fire, every round after that would not fully seat in the barrel. Im firing a Colt AR-15 HB.

I tried the forward assist to no avail and attempted 6 other rounds, all to no avail.

Nothing was stuck in the chanber or barrel or the bolt carrier.

when I got home, factory rounds would load as well as the reloads!!

Any ideas?

Ken




1979 W72 Nocturne Blue

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Re: question on gun jam
« Reply #1 on: January 20, 2009, 08:12:55 AM »
I'm not a gun guy, but maybe too much heat build up?
Larry


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Re: question on gun jam
« Reply #2 on: January 20, 2009, 08:15:26 AM »
Ken, any chance the round is sitting too far forward in the throat of the  barrel and the pin not hitting it? i remember you saying you had issues with the bullets moving in the crimp. Just a possible area to look into.

taman76

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Re: question on gun jam
« Reply #3 on: January 20, 2009, 08:35:10 AM »
Lots of things could cause this. 

Check your primers.  Are they getting really flat?  If so, you have too much pressure and need to reduce the load a bit.

Check your crimp.  Too much or too little crimp on the bullet.

Check your case length.  As you size the brass, it gets longer.  You  may need to trim them after sizing and before loading

Check your bullet seating and depth.

Lastly, did you de-lube the shells before seating the bullets?  Case lube is actually gets kind of sticky.

Lastly, how cold was it out.  Amazing how cold weather affects mechanics.


Rick

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Re: question on gun jam
« Reply #4 on: January 20, 2009, 08:51:43 AM »
Temperature shouldn't be an issue for the weapon itself.  The Colt AR-15 is a fine weapon and your use of it is well within the intended envelope of operation.

From what you're saying, it is correct that the cartridges wouldn't allow the bolt to close, but when you got them home the very same cartridges would seat OK?

That suggests that there was something in the chamber interfering with the cartridge seating, but it came out before you tried it at home -- but you say there wasn't.  Another possibility is that as suggested there was some excess lube on the case that got sticky in low temperatures, but either warmed up or got wiped off when you got home.

If the cartridges chambered OK at home then the overall length must be OK, but it would still be worthwhile to check that.  A cartridge gauge is a nifty tool to have around, even if infrequently used.

From what you are describing, the rounds that hung up were never fired, so it doesn't sound like a primer problem.  But I may not be understanding what you mean with that.

Re: question on gun jam
« Reply #4 on: January 20, 2009, 08:51:43 AM »

Rick

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Re: question on gun jam
« Reply #5 on: January 20, 2009, 11:33:40 AM »
Cold temps are always an issue with semi-autos if there is an oil film or lube. 

Inappropriate lubrication is always a problem, regardless of whether it's in regard to temperature or other factors.  My point is that the Colt AR-15 is designed to work across a rather broad range of temperatures so if Ken's in US territory he shouldn't be outside of those limits.  Using the appropriate lubrication, I really can't think of many places where it would be a problem for the design of the AR-15.

Some oils change change viscosity pretty quickly over a small temperature range, and when they thicken they become grease-like.

Rick

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Re: question on gun jam
« Reply #6 on: January 26, 2009, 08:21:04 PM »
Any more developments on this problem?  I'm always interested in hearing if the root problem was discovered.

Milly

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Re: question on gun jam
« Reply #7 on: January 26, 2009, 08:43:12 PM »
Have you tried completely different ammo? My semiauto Ruger Mark III .22/45 pistol won't shoot a whole 10 round magazine without a jam or "stove pipe" if I'm using Remington ammo but it will spit out Winchester ammo all day long without a misfire. Just a suggestion.
John
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Re: question on gun jam
« Reply #7 on: January 26, 2009, 08:43:12 PM »
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