Resizing and brass acting weird

[mshelton]

First off using Lapua brass, 6br .265 neck, brass has 2 firing on it.

Die is set up so that a sized empty case will just barley hold up the bolt handle with the firing control removed.

Problem, sized all the cases (50) and on checking them, halfish of them required a lot of force to close the bolt, the other half are fine. Tried running them through the sizing die once more and the same results. Had to rotate the die almost a full turn to get the problem brass to show minimal resistance on closing the bolt. Cases were cleaned with a Krazy cloth and lubed with imperial wax before sizing. Checked case length and the problem ones were within .003 of trim length, checked the necks and they were fine, checked the die for debris, inspected the cases and found nothing out of the ordinary but the brass just didn't want to act right. It's almost like they had a butt-ton of spring back.

Ended up just over sizing everything and firing the rounds, haven't gotten around to prepping the brass after that so it may have cleared it up but has anyone encountered this or have a clue what might be causing it?

 

[jonbearman]

It almost sounds like annealing is in order.Are they from the same lot?

 

[BoydAllen]

First of all, I would suggest that you get some type of tool that is designed to facilitate measuring shoulder bump in thousandths of an inch. (when you take the initial measurement of a fired case, I suggest that the fired primer be removed or re-seated below flush.) Secondly, I would like to know how much the base of your cases are being reduced by sizing, measured at their larges diameter above the extractor groove. The weakness in using bolt feel to gauge sizing is that if the die is a little too large at its base, case shoulders may have to be bumped back too far to get the feel that you are looking for. The only solutions to this problem are to get a die that is smaller at the back. or to polish out that area of the chamber.

 

[243winxb]

Had to rotate the die almost a full turn to get the problem brass to show minimal resistance on closing the bolt

The shoulder has now moved forward. It can take 3 or more firings, when only neck sizing, for the brass to form to the chamber. With your orginal die setting, i would guess the die was not contacting the shoulder. Now it is.

 

[amamnn]

This is the cure:

http://www.lewilson.com/casegage.html



or better yet:

http://www.redding-reloading.com/uniquely-redding/111-instant-indicator-headspace-and-bullet-comparator

 

[BoydAllen]

Having used several methods, I find this tool perfect for the job. http://www.hornady.com/store/Lock-N-Load-Headspace-Kit-With-Body-1-Each/

 

[Johnboy]

What it really boils down too is the fact of the brass itself never will be the same from case to case.One will be this the other this.So now as said 25 or so cases not resizing as the others.This just says one or two things to me. 1) the brass is thicker than the others in the neck/shoulder area.This alone will cause the brass to anneal differently from the others.It will all so cause the brass to work harden different from the others.( as said by you the spring back in brass ) 2)the metal chemistry will or never will be the same from case to case.( close but never the same )Now with that said yes,a said lot to lot will never be the same, we all can understand that pretty well.BUT even though say 2000 cases came from the same coil of copper doesn't mean that its all 'the same.The process to make the coil will change all over the board ( coil ) making it different all through the coil.The cooling the heating even the rolling process will change the chemistry of the brass through out the coil making it different.One other thing even the punching and drawing of the brass to make it a case will change the chemistry of the brass from case to case.

So I too see this all the time when reloading for a rifel.All I do is just adjust the die to push the shoulder back to resize the cases to where they are needed.( but only the ones that need it a little more ) not the ones that already fit the chamber of a rifel I'm loading for.Now the rest of these guys have given you really great info to a better way of bumping the shoulder back.For me I too use the way you said in your post but will add that I do not match shoot or need the accuracy these guys need.Maybe my thoughts or idea to your problem isn't 100% but its my thinking from what I have learned from making bottles and working with steel over the years.

 

[gunsandgunsmithing]

I made this gizmo for a good friend. Maybe he'll see this and post his thoughts. You simply drop the case into the fixture and set the indicator top on it, before and after sizing, to accurately check shoulder bump. Pretty slick tool!--Mike Ezell

 

[mshelton]

Mike that is a slick little tool, out of curiosity, what would something like that set someone back?

I think I may have found the problem, the brass may be from separate lots, shouldn't be but I have an idea of how it may have gotten mixed up. If it did it would have been 18 pieces, I resized and checked them last night, 18 were tight as the dickens going in the chamber, 30 just fell right in and 2 were semi tight, so I don't know if there was a mix up or not. The barrel in on a competition gun and only has 150 firings with this brass so I'm leaning towards just using all new brass, have one more box of the old cardboard box stuff, might have to turn the necks on that tonight and call it a day.

 

[gunsandgunsmithing]

Mike that is a slick little tool, out of curiosity, what would something like that set someone back?

I think I may have found the problem, the brass may be from separate lots, shouldn't be but I have an idea of how it may have gotten mixed up. If it did it would have been 18 pieces, I resized and checked them last night, 18 were tight as the dickens going in the chamber, 30 just fell right in and 2 were semi tight, so I don't know if there was a mix up or not. The barrel in on a competition gun and only has 150 firings with this brass so I'm leaning towards just using all new brass, have one more box of the old cardboard box stuff, might have to turn the necks on that tonight and call it a day.

I'd be happy to make you one...pm incoming--Mike

 

[243winxb]

Another cause can be spring in the press because the shell holder is not contacting the bottom of the FL die. Use the Redding competiton shell holder set. Makes every die a custom die!

Now you can control headspace. The new Redding Competition Shellholders are packaged in five piece sets in .002” increments (+.002”, +.004”. +.006”, +.008” and +.010”). Each shellholder has a distinct black oxide finish and is clearly marked to indicate the amount it will decrease case-to-chamber headspace. You can now easily adjust the shoulder bump to customize cases to your specific chamber.

 

[BoydAllen]

Before a friend got set up to anneal his .22-250 brass, he was working with other methods to reduce the variance of shoulder bump, within a given lot of brass, at one die setting. He uses a Rockchucker, and found that having the die touch the shell holder helped. He did this with aRedding Competition shell holder. Evenness of lubrication, and dwell time at the top of the ram stroke also influence bump. When he finally got around to annealing, THAT was the big change that really resolved his bump and neck tension variance issues. He uses a Hornady kit, with a metronome, and cordless drill.

 

[Zia Hunter]

I set up the dies for bolt and single shot rifles to bump the shoulder .001-.002. In most instances this precluded the die from contacting the shell holder in my Rockchucker which resulted in inconsistent sizing. Most instructions for setting up dies instruct you to contact the shell holder plus 1/8 of a turn. Although this will result in brass meeting specs, it may be oversizing the brass for a particular chamber. I switched to a COAX press and no longer have an issue.

 

[GSPV]

Mike made that bump gauge for me. It is the slickest thing since sliced bread. He put a lot of thought into making it easy to use and idiot proofing it.

I just de-prime the case, drop into the gauge chamber, and put the top on with the tip of the indicator on the same spot on the case head. Voila, you have a good, consistent measurement.

Mike's gauge was pretty much instrumental in isolating what was causing my inconsistent bump.

With the gauge, and a set of Skip's bump shims, you can get in the right ballpark without a lot of frustration.