Move chamber away from bolt ?

[Gregg C]

If I'm wanting to head space on the shoulder with a belted case, how much room for the belt would the chamber need ? Would lapping the bolt be an option? Some cases are hitting the top of the belt in the chamber. NOT conducive to accuracy, I think. Thanks.
Gregg

 

[ShtrRdy]

I don't know the "correct" answer for this but I suspect a gunsmith could cut the groove for the belt a little deeper with a single point cutter without touching the rest of the chamber.

 

[Gregg C]

I don't know the "correct" answer for this but I suspect a gunsmith could cut the groove for the belt a little deeper with a single point cutter without touching the rest of the chamber.

Wow, I had not even thought of that. Thank you, sir.
Gregg

 

[Rich Coyle]

I think you don't need to give it any thought. Fire your brass a couple times, measure the head to shoulder and use a gauge to set the brass back about .002". The belt will miss the chamber.

 

[Gregg C]

I think you don't need to give it any thought. Fire your brass a couple times, measure the head to shoulder and use a gauge to set the brass back about .002". The belt will miss the chamber.

Sorry, I'm not understanding what you're saying. Are you saying bump the shoulder back?
My issue is that the top of the belt is getting shined up and the base is showing drag marks from the bolt. It isn't every case. Seems like my chamber is a tiny bit short. Looking for how much clearance to give the top of the belt, and the best way to go about that.
Thanks.
Gregg

 

[Edd]

The best way to make it the correct size is with a reamer and a headspace gauge. The chamber needs to be the correct size. Your method of brass sizing doesn't change this.

 

[MudRunner2005]

If I'm wanting to head space on the shoulder with a belted case, how much room for the belt would the chamber need ? Would lapping the bolt be an option? Some cases are hitting the top of the belt in the chamber. NOT conducive to accuracy, I think. Thanks.
Gregg

The only way to headspace off the shoulder with a belted cartridge is to neck-size your brass after fire-forming them the first time they're shot, and your cases will be headspaced on both the belt and shoulder.

Most likely scenario, is if not all your brass are showing this issue, it is a brass-related issue. Measure a case that fits fine with your calipers, including the belt height (from top to bottom), and then measure the same measurements on a case that is exhibiting the problem you describe. If the measurements are not conducive to one another, then that will determine the brass to be the problem.

Also, one more question...Do you mix your brass? Do you use mixed headstamps and mixed batch lots of brass? Sometimes with the cheaper factory ammo, you get large swings in brass quality control, and this can happen.

If the brass proves to be the problem, buy some brand new high-quality brass, like Nosler. It's been very consistent for me with all my belted cases, and nary a problem.

 

[Gregg C]

The only way to headspace off the shoulder with a belted cartridge is to neck-size your brass after fire-forming them the first time they're shot, and your cases will be headspaced on both the belt and shoulder.

Most likely scenario, is if not all your brass are showing this issue, it is a brass-related issue. Measure a case that fits fine with your calipers, including the belt height (from top to bottom), and then measure the same measurements on a case that is exhibiting the problem you describe. If the measurements are not conducive to one another, then that will determine the brass to be the problem.

Also, one more question...Do you mix your brass? Do you use mixed headstamps and mixed batch lots of brass? Sometimes with the cheaper factory ammo, you get large swings in brass quality control, and this can happen.

If the brass proves to be the problem, buy some brand new high-quality brass, like Nosler. It's been very consistent for me with all my belted cases, and nary a problem.

Thanks for your response. I may be chasing ghosts. The one case I have left that did that, I turned into a dry fire case. Of the original 40 cases I started with, only 15 are left, and none of them exhibit this. The second forty cases I got, all chamber fine. I measured the one , and it only measures bigger than a new case in one spot. It is +.001 right above the belt. Belt is actually shorter than new by about .001. Diameter is smaller, head is smaller....gotta be the dreaded belted case bulge I have heard about . It still closes tho, and its retired, due to neck splitting. As to lots , I don't know, I did not know enough to check . Its Weatherby head stamped brass, so, Norma, I guess. And its the big Weatherby, so I guess it will Always be Norma. This morning when I posted this question, I thought I had had an epiphany-Now it looks more a brain fart, instead. Thanks for the post, helped alot.
Gregg

 

[AZShooter]

Nice to hear the issue was the brass. Far easer to deal with that than the chamber.

If the belt still bothers you, if you had access to a lathe you could remove the belt. I once did that for a 1000 yd bench shooter who had his rifle chambered for the 300 weatherby improved with a reamer that didn't cut a belt. Used a collet chuck and cut close then fine sanded to match body. I know it sounds crazy but it worked.

Ever read some wildcat books? IIRC PO Ackley's book talked about wildcatters back in the day that were creating belts on beltless cases! Now that was some crazy stuff.

 

[Gregg C]

Nice to hear the issue was the brass. Far easer to deal with that than the chamber.

If the belt still bothers you, if you had access to a lathe you could remove the belt. I once did that for a 1000 yd bench shooter who had his rifle chambered for the 300 weatherby improved with a reamer that didn't cut a belt. Used a collet chuck and cut close then fine sanded to match body. I know it sounds crazy but it worked.

Ever read some wildcat books? IIRC PO Ackley's book talked about wildcatters back in the day that were creating belts on beltless cases! Now that was some crazy stuff.

Interesting post, thank you. I have actually thought of that ! And how did he do, do you remember ? I haven't read much of that which you speak but I think I will, as I think it sounds fascinating. Custom reamer, eh ? So , lose the belt , less body taper, no radiused neck.....hmmmm.
Thanks
Gregg

 

[Rich Coyle]

Below is a photo of a Jamisen 9.3X64 Brenneke, a Norma 7 Rem Mag with the belt turned off, and a fireformed Norma to 6.5 SLR. I used a bunch of the 9.3X64 cases. When I wanted to order more I couldn't find any so hired a local machinist to turn the belts off and cut a new rim in the Norma cases.

 

[Gregg C]

Below is a photo of a Jamisen 9.3X64 Brenneke, a Norma 7 Rem Mag with the belt turned off, and a fireformed Norma to 6.5 SLR. I used a bunch of the 9.3X64 cases. When I wanted to order more I couldn't find any so hired a local machinist to turn the belts off and cut a new rim in the Norma cases.

View attachment 87112

Ok, my head is spinning really fast now.
Gregg