Need Help With Contender Carbine/ Barrel Problem I Think

[HuntinNut]

 Awhile back I bought my son a Contender carbine (not G2) for youth deer season. I decided on a 6.8 barrel thinking it would be a great deer round. Anyway I cannot get the rifle to fire 100% without misfires. Ive polished the lugs, put another washer in the stockbolt, cleaned it & tried three kinds of factory ammo. I even got it to fire about 30 rounds of my primed brass with just two misfires and thought it might be the hard primers in the factory stuff, but after reloading some its back to 3-5 will fire and 2-3 wont. Im at a loss of what to try next. Im a DOD armorer so I know alittle something about firearms, but this one has me stumped. Anybody have any suggestions??

[cwlongshot]

How is the head space?  If you seat a round in the chamber does it sit below flush?
Also have you used any other barrels on the frame? Does it do it with any of them?
 
CW

[Keith L]

How about hammer spur extension?  If you have one on try removing it.

[David D.]

Only two things have ever caused me to have a misfire. Lock up and head space. Head space to short and have misfires. Head space to long and this creates a lockup problem leading to misfires, lock up can also be a problem from the locking bolt. Normally a case to long you can snap the gun closed and the misfires go away. But when I have done this so has my accuracy went away.

[HuntinNut]

cwlongshot.... The headspace looks right to me with the brass sticking just above flush. I dont have my other Contender here right now. I loaned it to a buddy for his son to use for youth deer season. Ill be getting it back this week though so I can swap some parts around to see if I can figure something out.
Keith L.... No hammer ext
 
 
 
 
 

[cwlongshot]

cwlongshot.... The headspace looks right to me with the brass sticking just above flush. I dont have my other Contender here right now. I loaned it to a buddy for his son to use for youth deer season. Ill be getting it back this week though so I can swap some parts around to see if I can figure something out.
Keith L.... No hammer ext

That is NOT correct! This is a head space problem! Either your shoulder of your case is too far forward, or the chamber of your barrel is not cut deep enough. OR maybe the brass is from a different rifle with this problem and your dies have not moved the shoulder back to SAMMI spec.
 
Is this a reload or a factory loaded cartridge?

 If you eliminate any interference from the extractor, the brass should drop in the chamber and sit flush with the breech.. In other words, drop the loaded bullet into the chamber and then check it with a steel straight edge. there should be ZERO GAP across the complete width of the barrel. Having the steel in 100% contact with the steel of the barrel AND the brass of the case. NOT above and NOT below.
 
CW

[HuntinNut]

 I just checked it again with a loaded Hornady round and its flush. I checked it before with once fired SSA brass. I could see a problem if the chamber was too deep causing the brass to sit in too far and it not allowing the firing pin to hit it fully, but if the chamber was alittle to short and the barrel was fully locked up it would basically bump the neck back for you.  Either way the headspace is right..

[jbrown]

I recently had a similar problem with my 45/70. I replaced the hammer spring and all is well. The old hammer spring didn't look well once removed. Mine would shoot some ammo sporatically, and just dent the primer on others.

[HuntinNut]

OK so I switched the barrel out today to another frame and tried to refire some of the dented primer ammo. Ten of them would not fire. I didnt try to fire any other ammo, but will try tomorrow. I think its in the barrel so what should I be looking for now??

[cwlongshot]

Sorry my friend I am at a loss... I don't know the 6.8 very well.
I feel its a headspace issue with the ammo or something in the way that barrel is locking up on the frames...
 
Wish I could help..
 
CW

[David D.]

Sorry my friend I am at a loss... I don't know the 6.8 very well.
I feel its a headspace issue with the ammo or something in the way that barrel is locking up on the frames...
 
Wish I could help..
 
CW

I agree!!!!!

[OK hunter]

I have the same problem with my 6.8.  Headspace has always been a bit of a mystery.  I couldn't ever get my hands around it until Cvlongshot explained it.  Thanks for that.  I had some significant issues with S&B ammo.  Not as much with SSA ammo.
I'll now know how to check the headspace.

[hoghunting]

but if the chamber was alittle to short and the barrel was fully locked up it would basically bump the neck back for you.

 The problem is your barrel is not fully locked up. I had the same problem with 7-30 Waters cases formed from .30-30s. I was getting light primers hits on some of the cases and others worked just fine. The cases that required a harder slam to lock the barrel had the light primer hits. The longer cases kept the barrel from fully locking and letting the hammer go completely forward. Bumping the shoulder back when resizing corrected the problem and the barrel didn't require a slam to lock.

[Dezynco]

Try taking out the locking lugs and give them a good polishing with a stone or fine sandpaper, just in case the lugs are not slipping into the frame securly.  This can be a problem more often than you would think. See the sticky about fitting an old barrel to a G2 frame.
 
As far as the headspace...
If the chamber is a little too short, even a couple of thousandths, the case will sit too far out of the chamber.  When the hammer strikes, the case will be driven forward into the chamber, thus causing a misfire.  This can also be caused by the shoulder of the case being too far forward.  The forward movement is causing a "cushioning" effect.  This can even happen with factory ammo - factory ammo has been known to be less than perfect.
 
Try firmly closing the gun, open it then firmly close it again.  This may crush the cartridge into the chamber and allow the gun to fully lock up.  Worth a try.  I'm still betting on the locking lugs.
 
Wouldn't hurt to install a heavy locking bolt spring and a heavy hammer spring.  I installed both and misfires are a thing of the past.

[Preacherman]

I have a 6.8 MGM pistol barrel if you don't close it with authority it will sometimes misfires.
I vote not locking up.
Preacherman

[David D.]

If the barrel locks up without a round in the chamber without slamming it closed the locking lugs are not the problem. If you have to slam it closed with a round in the chamber then it is a headspace issue. Slamming closed a round will push the shoulder back, but can still cause the barrel not to get a full lockup causing misfires and sometimes the gun popping open upon firing.

I shoot an Encore in 22Hornet that we all know is a thin case. I had this same thing happen with it.  For some odd reason I didnt get all my cases sized the same. Some would require slamming to get them to fire. The slammed closed rounds were also no where as accurate as the ones I didnt. Head space is critical to proper operation of the TC's.