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[DRH]

xyz

[ccandgc]

[paratroop]

Check the inside of the tube for marks where the hammer might be hitting on the top. Does the trigger group pass a function check? Did you smooth any of the parts out? If the "disconnector" is not working, it will let the hammer ride forward. Sometimes, I guess the bar has to be shimmed one way or the other. Mine had to be shimmed in the center. Also make sure the block the disconnect spring goes into is not moving. It should be welded in place.

[grossekatz]

The case bulging is normal for these things. The bolt does not lock it just smashes the round into battery. Seems to be because of its open bolt design. If the hammer is not resetting its probably in the trigger pack. There were lots of issues with the ones in our group buy. Most could be solved with hand fitting. Pull the pack apart and re assemble on the outside of the fire control box. You should be able to see where the problem is when operating it by hand.

[grossekatz]

I would think that a little case bulge at the rear might be normal for an unsupported case sticking out of the barrel but I can't imagine it shortening the brass pre-ignition like that is normal or safe. I have a three other blowback pistol caliber carbines and they don't do that. I am thinking I either need to cut the drive spring down to reduce the force or ream the chamber slightly so the bolt face contacts the rear of the barrel before it crushes the cartridge. i have no idea which would be the better or correct choice. Maybe I need to do a little of both?

Remember these guns were fixed firing pin open bolt so they do not really headspace, they would just feed forward until the case mouth bottoms out on the chamber and fire. I have hundreds of rounds through mine and not had a single case failure. All the other m31's I've seen do it to some degree. I am fairly certain its normal for these screwy rifles. I would not recommend cutting the spring because that is integral to keeping the bolt closed just long enough for the pressure to drop. if it really bothers you that much you could probably ream it but, I think the bolt smacking the barrel with that much force would cause problems fast.

[grossekatz]

I am near you in Castaic. let me know if you want me to take a look at the trigger pack. I can show you what I had to do to mine.

[GUNNTZ]

Grosskatz, give the OP and the rest of us some info. Mine is doing something similar. The real iffy thing for me is that I'm getting a burst of two then no lock up. TNW sent me a pic and some instructions, but it makes me wonder if it is that simple.

[sd_shooter]

I had to file the top of my hammer and shim the trigger bar. Make sure the plug at the end of the main spring is on the right way, it should not be crazy tight like that.

[grossekatz]

Grosskatz, give the OP and the rest of us some info. Mine is doing something similar. The real iffy thing for me is that I'm getting a burst of two then no lock up. TNW sent me a pic and some instructions, but it makes me wonder if it is that simple.

I had to enlarge the slot in The disconnector to get the bar to travel far enough forward as well as re cut the engagement surface on the hammer. That worked for me but I have seen some that the holes were not drilled right. Those trigger boxes went back to tnw. They are pretty good about replacing problem parts.

[GUNNTZ]

I will post up the pics/info they sent me

Edit:
Here's what TNW sent me based on how I described my issue to them. I have yet to pull it apart and check/modify it, just no time.

[Aaron707]

It looks like too tight of headspace may be causing the cases to compress. Do you have any gauges to check it with?

[AJAX22]

Definitely short chambered

Probably run real good with 380 though

Get a gunsmith to ream it to a prop per depth

[mrlonewolf]

Easy fix.....

I've encountered the same scenario many times before.






PS. Forget about about filling,.... do you have a welder????, PM if you would.

[ColdDeadHands1]

Easy fix.....

I've encountered the same scenario many times before.






PS. Forget about about filling,.... do you have a welder????, PM if you would.

Well, what is the fix? No need to PM, many of us are watching for the same information.

[mrlonewolf]

Absolutely.

Please allow me a few minutes to take and upload pics.