Brass click part deux - same reamer

S

savet06

Mike Suhie
Since the cone depth wouldn't likely cause the clicking issue - the same reamer was used to cut this chamber as multiple other barrels, same sizing die and fireforming process was used though done in a different barrel with COW.

Given the consistent procedures and equipment would simply cutting a tighter chamber have done this? Would fireforming in a slightly longer chamber and then needing to bump the shoulders back .002 after the first firing have caused this brass to take a set?
We have 200 pieces of brass prepped for this gun and I obviously don't want to replicate this problem.
Sorry guys, but my mind doesn't tend to let go of a problem until I have a good idea of what caused it in the first place. This one is holding tight and living rent free at the moment.
Mike
 
Is the brass new, only fire formed? If so, then yes, I think you're on the right track to finding the cause. A tighter chamber can cause click. Classic bolt click is typically comes from the base end of the case being to tight when fired. The fire form bbl, if even slightly fatter chambered, can be the root problem. The brass develops a memory and wants to go back to its largest ever state when fired. You can try a smaller die or polish the chamber a bit. Either will likely help but I'd lean toward polishing the chamber because the smaller die will likely only help for a while.

As to length, it can also cause issues but is more controllable by bumping a tad more. But again, in both cases, the brass wants to go back to its largest(and longest) ever state.
How much longer is the fire form chamber? If only a couple of thou or so, I don't think it'll be a big problem but if several thou long, it will...IME. Brass that's too long when fired doesn't give the classic click of the brass that's too fat. It'll give heavy bolt lift from the start upon raising the bolt. Classic bolt click is mostly felt at the top of the stroke, where the primary extraction cam surfaces begin pulling the case from the chamber. Just my 2 cents. Hope it helps.
 
Thanks, Mike, it does help a lot. I have done maybe 15 or 20 barrels at this point and have not come across this in any of the 30br chambers. My first clue was the that brass from another gun that I did for my friend would not fit in this chamber after being full length sized. We moved forward because we hadn't had any issues before and why would they start now....well they did.
The brass in question was only fireformed in a different chamber from the same reamer to be clear (lot of brass flying around in this post!). After 4 firings in the "tight" chamber the click started.
 
Mike, a couple of thoughts after working with a 30BR having issues as you describe:

-Have you tried a light stress relieving of the 'clicker cases' at the body/shoulder junction before f.l. sizing?
-When pushing the shoulders back during sizing, the body/shoulder junction diameter can actually get larger.
-How do the sized cases feel when you chamber them with a stripped bolt?
-How are you measuring the shoulder 'bump' back and what are the before/after sizing 'bump' dimensions?

Good shootin' -Al
 
Unfortunately, this is my friend's gun though I can confidently say he is meticulous with his prep and measurements. Not sure if he anneals/stress relieves after necking up or sizing initially, but for sure after fireforming.
Cases with the click will size well, and the bolt handle goes down about 3/4 and then a light touch. He had been sizing a little extra to try to reach down a little further, but still had a click on the majority of cases.
Measures headspace with a bump gauge and digital mitutoyos.
There was something different about this chamber from the beginning as other brass he had used would not even start to go in.
 
So....is the 'click' right at the top of the bolt opening where the camming starts? Just heavy bolt lift as soon as the bolt is opened and all the way through the cycle? Or both? -Al
 
I ran into this once I started cutting properly sized chambers. ;) I had to make a body die to 'fix' the brass when used in the tighter chamber. Tired brass simply expanded enough that I needed the body die at each loading so that got tossed. Once-fired didn't have that issue. This was in a magnum case.

There's been discussion on a number of forums about the 65 PRC. It seems current sizing dies do not size the base enough if the chamber is tight resulting in clickers after a couple reloads; some even after the first firing. Alex Wheeler came up with a reamer with a larger base that has solved the issue. I've cleaned up by hand a number of folks' chambers and all their issues disappeared.
 
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I have often seen

the recommendation on here to open the ass of the chamber up a couple of thou using some emery on a dowel. They all say it works. I've meant to do one of mine to see but never think to do it.

Pete
 
Pete Wass said:
the recommendation on here to open the ass of the chamber up a couple of thou using some emery on a dowel. They all say it works. I've meant to do one of mine to see but never think to do it.

Pete
Click to expand...

Pete, I just order my reamers with a fatter base and my reamers for my sizing dies .003 smaller at the base and .002 at the shoulder.
 
Sounds like

Butch Lambert said:
Pete, I just order my reamers with a fatter base and my reamers for my sizing dies .003 smaller at the base and .002 at the shoulder.
Click to expand...

The right thing to do. As cases are shot, they grow and get harder and harder where they aren't suppose to be annealed so one has to do something.

Pete
 
Butch Lambert said:
Pete, I just order my reamers with a fatter base and my reamers for my sizing dies .003 smaller at the base and .002 at the shoulder.
Click to expand...

Yes sir! I do the same or close to it, depending on the cartridge. I like .003 at both places on my Grendel based stuff but most of these issues come from the web area rather than up top.. Splitting a fine little frog hair there, though. But yes, IME, polishing the chamber does the same thing. Sometimes we take things to extremes and try to be too perfect, if there is such a thing, and cause ourselves more trouble rather than less. Spec'ing reamers too small is a good example of that. I've never found a reamer that's a thou or so smaller at the base shoot better than one that is not quite that small. But I've seen clickers from such a setup, a lot of times. A few years back it was common to spec reamers very close to virgin brass dimensions. I think that fad has mostly passed, but there are still a lot of those reamers and chambers out there. IME, they do nothing but cause trouble. Once a piece of brass is fired, it then becomes about the relationship between the chamber and the sizing die...as it should be. As much grief as Kiff catches of late, he's still a wealth of knowledge in terms of knowing what die makers like Redding are using to make their dies. This knowledge allows us to spec a chamber reamer that works great with an off the shelf bushing die. Nothing wrong with custom dies but imo they are just an unnecessary added cost, if the chamber is cut for a Redding or similar die. The end result should still be the same...That being, sizing of the brass just enough to work RIGHT. That can be done with the die or the chamber reamer. Something to keep in mind is, the die has to be smaller than the chamber and just because the die is say .003 smaller doesn't mean the brass comes out that small due to different springback at the base and shoulder areas. In my grendel and ppc stuff, .003 smaller die yields about .0015 clearance at the shoulder and about .0005-.0006 at the base on brass that has 2-4 firings on it. That's key because as it work hardens, that clearance becomes slightly less and less due to the brass not wanting to stay put when sized.
 
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