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Chambering Issue

ldpace

Plastic
Joined
Nov 30, 2010
Location
Atlanta
I have just cut a new barrel for a 30 Br and when I chamber rounds some of them are difficult to chamber. Even empty brass, full length resized and Trimmed for proper length can be difficult. Some chamber fine, some have a stiff bolt closure but some require the bolt to be Pushed Forward and a definite "Click" can be heard before the bolt will close, you can feel the bolt move slightly forward before the bolt will close, but it is stiff. This is with the firing pin, extractor and ejector removed. Head space is fine, checked and double checked. The chamber looks fine, although I do not have a bore scope. Is there a fix or should I just move the chamber forward a thousandth and reset headspace? Thanks for any help.
 
If the cartridge you are working with is 303 Brit, the headspace is determined by the rim thickness. I am not sure what 30 Br is. Regards, Clark
 
Thanks Clark, the 30 BR is a benchrest caliber derived from the 6 BR cartridge, necked up. It head spaces off the shoulder.
 
I have removed the extractor from the bolt to eliminate that possibility, But to answer your question it is a BAT 3L. I have used the same action on a different barrel for years, I cut the chamber on that barrel with the same reamer. I am not sure where to look.
 
I am using the same Redding Competition FL neck Bushing Die that I have used for years on other barrels cut with this reamer and using the same action.
 
I had basicly the same problem on a 6 BR. I got a Wilson case gauge and found they were not sized down enough even though the shell,holder was bearing on the bottom of the die. Started measuring shell holders and found quite a variance in the height. I set up and milled .005 off of the top of the holder making my cases perfect in the Wilson gauge, and making for a sweet bolt closure. Just my experience. dae
 
Start measuring the brass that goes in easy at various places on the case then compare the readings with the brass your having a problem with. Sounds like you have some variations in the brass
 
I'm pretty sure a little bit more room in the chamber will fix this. So, yes, just ream it a couple thou. deeper.
 
Sometimes when you cut a chamber to the minimum head space, the sizing dies will not push the shoulder enough to chamber easy with out modifying your die or shell holder. Gary
 
Cut the neck and shoulder of the chamber into a scrap of barrel. You should have a 1" minimum length piece laying around from this one, right? ;-)

Face the opposite end nice and square, and use it to measure headspace of the cases. I like to face them until they read 'zero' on the GO headspace gauge. Exact length doesn't matter, just that the needle on the dial caliper is on zero. If you use digital, just zero it. Gives you some idea of how the fired cases, and your chamber, relate to the headspace values.
 
All great ideas. I have a hornady gauge that mounts in the calipers to measure how much you bump the shoulder back. Though I usually only bump the shoulders back .002 I have bumped some of the brass back .005 and it still hangs up.
 
The stem is backed off one eighth of a turn per instruction. That is the way I have always sized that brass.
 
The distinctive click before they chamber with extractor removed would have me measuring case head diameters.

This^^^^
Measure the cases in front of the extractor groove. If they are multiple times fired, they may be springing back and end up a little big at the base. A cerrosafe casting of the chamber will help you understand what diameter they need to be. Headspace setback on the brass is easy to measure with the Hornady tool. If you are getting variation, it could be how you are setting up the sizer, or the brass might want to have the shoulder annealed.
Do you have the problem with new unfired brass?
 
had a similar experience with a 220 swift Ackley. Redding dies came with the gun and I happen to know a fellow that worked there.He suggested i provide 3 spent shells and he took them in and measured. turns out the dies needed to be cut 20 thousands. the chamber reamer used was wore down and did not cut to Ackely specifications. no problem after dies were corrected.
 
I have just cut a new barrel for a 30 Br and when I chamber rounds some of them are difficult to chamber. Even empty brass, full length resized and Trimmed for proper length can be difficult. Some chamber fine, some have a stiff bolt closure but some require the bolt to be Pushed Forward and a definite "Click" can be heard before the bolt will close, you can feel the bolt move slightly forward before the bolt will close, but it is stiff. This is with the firing pin, extractor and ejector removed. Head space is fine, checked and double checked. The chamber looks fine, although I do not have a bore scope. Is there a fix or should I just move the chamber forward a thousandth and reset headspace? Thanks for any help.

Blue the fit. Then you know where the interference is, then you can fix it.
CarlBoyd
 
If the base is oversize, he'd have to be knocking them out with a cleaning rod with no extractor installed. Is (are) you?

If that's the case, brass expanded oversize, could be the first barrel had an oversize chamber and the die won't bring them down enough to work in the new one. Yeah, same reamer, but maybe an alignment problem when it was cut leaving it oversize at the base.

Still have the old barrel? A quick test dropping one of the tight cases in both might show something. It could be only a thousandth, and you'd probably have a hard time measuring that with calipers. Gauge pins would be a better bet. Or measure the diameter an 1/8" in and turn up a plug that size. See how far it goes into each barrel.
 








 
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