.002 shoulder bump tight in chamber

reread post #17 and then my post should make sense.

The bump at the top of the case is likely not the issue.... measure and confirm either way.

reread post #18... it is rare for there to be a significant mismatch in dimensions with modern chambers and dies BUT it can happen.

don't get caught up in the TYPE of die... measure and figure out what DIMENSIONS are necessary to properly shape that case to the rifle. You can even try other brands of dies and you might find a better fit. Dies can vary in dimensions

Have a look at the lock up of your action. You may very well need to bump the shoulder more then ideal because of the action itself but that will lead to shorter case life and other forms of grief.

So try and identify WHERE the problem lies. If a die/shellholder mismatch, that is an easy fix... if an action issue, then you have to make other decisions.

Jerry
 
I think you’re fixating on the amount of shoulder bump. Ordinarily thats not a problem; since normally it is directly reflected in the headspace. Trouble is “Normally” isn’t the same as “Always”.

If the bolt handle is meeting resistance, the headspace is functionally zero for that case/cartridge no matter what the gauge says. As long as the casehead is plastered to the boltface like a road killed frog to the highway case stretch isn’t going to be a big deal. Thats why we can fireform H&H cases into weatherbys, form AI cartridges, use the O ring trick on Enfields, form false shoulders, or sometimes just seat bullets long and move shoulders around with casual ease. :)

If you didn’t have a bump gauge you’d be happy right now. ;)
 
I will be a bit blunter than Dogleg - re-read Post #3. You "drank the kool-aid" and spent money to get a gizmo that gives you a number, and now struggle about the "number" - is NOT important - if anything, it was supposed to be an aid to fit your cases into your chamber. Don't loose sight of what you are trying to do - is not about getting a "number" or getting a "correct" number - is about getting your cases fitting "snuggly" - your die, your brass, your chamber.
 
Dogleg said:
I think you’re fixating on the amount of shoulder bump. Ordinarily thats not a problem; since normally it is directly reflected in the headspace. Trouble is “Normally” isn’t the same as “Always”.

If the bolt handle is meeting resistance, the headspace is functionally zero for that case/cartridge no matter what the gauge says. As long as the casehead is plastered to the boltface like a road killed frog to the highway case stretch isn’t going to be a big deal. Thats why we can fireform H&H cases into weatherbys, form AI cartridges, use the O ring trick on Enfields, form false shoulders, or sometimes just seat bullets long and move shoulders around with casual ease. :)

If you didn’t have a bump gauge you’d be happy right now. ;)
Click to expand...

Okay i like the way you put this, put my concern to bed.

Thanks.
 
Potashminer said:
I will be a bit blunter than Dogleg - re-read Post #3. You "drank the kool-aid" and spent money to get a gizmo that gives you a number, and now struggle about the "number" - is NOT important - if anything, it was supposed to be an aid to fit your cases into your chamber. Don't loose sight of what you are trying to do - is not about getting a "number" or getting a "correct" number - is about getting your cases fitting "snuggly" - your die, your brass, your chamber.
Click to expand...

Just a gizmo till a guy doesn’t realize he’s bumping his shoulders .010 and separates a case head.
 
Maybe want to consider that a "skinny" chamber and a "fat" die result in "tight" that has nothing to do with shoulder bump. Idea is to get snug fit. Shoulder, body, case head. Believing that only "bump" counts, overlooks that many cases taper from back to front - so, yes, a .010 shoulder bump may result in easy chambering, because brass now fits at the rear part of the body - it has been forced a bit further up that taper within the die - and you are correct - inadequate "fit" is main part of case head separation, with sane pressures - but can be more than just where the shoulder is sitting within that chamber. Issue is very much not so much about a case previously fired in your chamber - lots of hand loaders are trying to fit previously fired cases from another chamber - can be longer, shorter, skinnier, fatter than theirs.
 
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I'm not a fan of using cam over when using Redding Comp shell holders.
I make sure my FLR die is screwed in one turn beyond cam over with a std. shell holder then proceed with the +.010 shell holder on a fired case and check for case fit in my rifle. If the bolt does not close, use another fires case and the +.008 shell holder and so on till you get a bolt closure you are happy with. Then if you want to know what it is, measure that and compare with a fired case.
If you read the Redding instructions it says " The shellholder should be adjusted to make firm contact with the bottom of the sizing die during the case sizing operation." By using press cam-over it is subjective as to how much force is required. And if you understand leavers the cam-over actually goes over-center before it stops.

If your interested.
https://www.redding-reloading.com/t...a-custom-die-with-a-simple-shellholder-change

David
 
257Roberts said:
I'm not a fan of using cam over when using Redding Comp shell holders.
I make sure my FLR die is screwed in one turn beyond cam over with a std. shell holder then proceed with the +.010 shell holder on a fired case and check for case fit in my rifle. If the bolt does not close, use another fires case and the +.008 shell holder and so on till you get a bolt closure you are happy with. Then if you want to know what it is, measure that and compare with a fired case.
If you read the Redding instructions it says " The shellholder should be adjusted to make firm contact with the bottom of the sizing die during the case sizing operation." By using press cam-over it is subjective as to how much force is required. And if you understand leavers the cam-over actually goes over-center before it stops.

If your interested.
https://www.redding-reloading.com/t...a-custom-die-with-a-simple-shellholder-change

David
Click to expand...

I like using cam over, I believe it keeps my stroke more consistent, I usually load 300 rounds at a time, I know if my arm gets sore as long as I feel the pop over centre it’s even pressure every time.
 
When brass fires it conforms to your chamber. When you bump the shoulders back 2 thou - there is going to be 2 thou of clearance between your chamber and the shoulders of your sized brass.

If you are actually bumping the shoulder back 2 thou - then something else other then the shoulder is causing your issues.

Questions:

- When you say you are getting resistance, is this with a freshly sized piece of brass, without a projectile?
- Is the same brass with 4 thou shoulder bump entering the chamber with no resistance?

I would take a sharpie, mark up a freshly sized piece of brass (bumped 2 thou), and see what is interfering with your fit. Wherever the sharpie marks are rubbed off, is where your issue lies. You shouldn't have to bump the shoulders 4 thou - something else is going on.

I personally believe the problem lies somewhere other then the shoulders, assuming you are measuring correctly. Perhaps you have a tight neck reamer, or the base of the brass is not being sized enough. 2 thou should be more then enough clearance to chamber properly.
 
Also, after several cycles the juncture between the neck and shoulder will thicken.

I skim turn the necks initially and again after several cycles as chambering becomes more difficult.

This could be some of your issue (OP)
 
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