case separation

[speedgun]

I had the very first round of a batch of 25-06 loads fail to case separation. The case had been loaded and F/L resized 3-4 times. It was loaded with 55.9 gr of RL22, 100 gr Nosler B-Tip, 3.20 aol. I'm a beginning reloader and as of yet don't have a chrono. I had previously fired these cartridges with 56.9gr of RL-22, but reduced it to 55.9 because of primer flattening. Any thoughts as to culprit?

 

[mmcu]

Perhaps you are setting your shoulder back too far when full length resizing and creating excess headspace.

 

[CatShooter]

Cases only separate from headspace.

Your FL die is sizing the case too much. Back it off 1/4 of a turn.

 

[speedgun]

Should I throw all my cases that have any indication of a ring around the base away?

 

[dmoran]

Yes, I suggest to cue out the ones with obvious rings.....

Also suggest to measure the amount of setback to your sizing, so that you can adjust your die to not be excessively pushing the shoulder back, but yet pushing the shoulder back to adequate clearance.

Good Luck
Donovan

 

[speedgun]

I just reviewed the directions for the die and it says to screw die in until it touches case and then run it in an additional 1/8-1/4 turn. I think I had been running it in a 1/4 turn. What do I need to look for to know I am getting it adjusted correctly?

 

[strut64]

Another cause is that you are loading on the high end of pressure. A similar thing happened to me with 270 Win loaded at the top of the load chart. Try backing down a 2 or 3 grains. Your bullets will still be plenty fast and won't abuse the case as bad.

 

['Freak]

Backing the die out the press 1/8th of a turn will reduce the amount the shoulder setback by ~ .009”

1/12th of a turn, or same as one hour’s movement by the hour hand of a clock, will reduce the amount of setback by ~ .006”

1/16th of a turn gets you a ~ .0045” reduction

rotating the die only 5° gets you a ~ .001” change.

Read this article for the ‘how come’ of it, and be sure to follow any links.

http://riflemansjournal.blogspot.com/2010/05/reloading-case-head-separations.html

 

[K22]

Assuming the head space in your rifle is with spec which can be check by a gunsmith, you need a means to properly set up your full sizing die to achieve a .001 to .002" shoulder set back from a fired case in your rifle.

The Hornady Head Space tool is an effective and precise way to measure shoulder set back. You will also need a quality caliper to use the tool.

Most likely you're over sizing the cases causing excessive head space.

 

[searcher]

I would suggest buying a Hornady Headspace tool (about $35.00 or $40.00) which allows you to set up your sizing die correctly. It attaches to your calipers and you measure a fired case and keep adjusting your die until the newly sized cases are about .002" or so less in measurement. Many will debate how much to set the shoulder back - but yours is being set WAY to far back. This tool will tell you how much.

 

[CatShooter]

I just reviewed the directions for the die and it says to screw die in until it touches case and then run it in an additional 1/8-1/4 turn. I think I had been running it in a 1/4 turn. What do I need to look for to know I am getting it adjusted correctly?

To start, turn it down until it touches the raised ram and then back it off 1/4 of a turn...

Then fire some new cases. IF you can close the bolt on the fired case with little or no resistance, than load them, and shoot them.

At some point, they may get to the point that closing the bolt is difficult. At that time, start turning the die down a teeny amount (1/50th of a turn) and try the case again, then chamber it - if it is still hard to close, turn the die down 1/50th again and repeat - keep this going until the bolt closes with just the slightest resistance, and lock the die in place.

Easy peasy

 

[speedgun]

Thank you all for your responses. This is something of which I was totally unaware. I've learned and now I'll be ordering some headspace gauges. How dangerous was that case separation, because I'm not interested in using brass that I may have inadvertently damaged.

 

[riflewoman]

I also suggest using a Wilson case gage. The Hornady tool is OK but the Wilson is easier to use, IMO.

 

[Lapua40X]

Should I throw all my cases that have any indication of a ring around the base away?

IMO, No ... the tell tail ring after that occurs near the base full length resizing can be misleading.
When I didn't have a bore scope or other method of viewing the inside of the case, I used a pick (click link below) made from a paper clip with a piece of 1/4 inch dowel as a handle to feel the inside of the case. With a little practice I got pretty good at identifying and separating cases that were salvageable from those that were not.

http://riflemansjournal.blogspot.com/2010/05/reloading-case-head-separations.html

 

[savagedasher]

Being a new to loading your tool are more the likely limited just like all are telling you over resizing your brass. The best way to fix the problem is take a case that you haven't sized back you die back 2 turns from where they are touching when the ram is up .size a case with the dies back off. That will just neck size. Load it and shoot . a couple time of doing it . the case should start getting had to close. turn you die very slow and size . Keep doing it till the case will chamber. Lock the ring and you should be good to go. Save that case and when you can afford to buy a bullet seating tool you can also use a 40 cal bullet seating tool for checking the case from base to shoulder. Larry

 

[DeltaBravo]

Speedgun,

I use Tony Boyer's method of FL sizing. Take a caliper and measure the body/shoulder junction on a couple fired cases. Lock that in. FL size the cases and measure again. If properly sized, the calipers will now slide down over the body by about 1/8" - much more than that and you're over sizing. Doing it this way will allow the bolt to chamber the case with almost no headspace, eliminating a lot of inconsistency. To make sure you've got it right, take the firing pin assembly out of the bolt and then close the bolt on the re-sized case. The bolt should close about half way or so with no force, and the rest of the way with some amount of force. I've used this method for a while now and have had no issues with chambering or firing. My brass also doesn't get a chance to grow due to excess headspace.

YMMV of course.

Dennis

 

['Freak]

A 7/8 -14 die has 14 threads per inch so it’ll take 14 full revolutions to move the die in or out the press exactly one inch. One full turn will move the die 1/14 = .0714”. The math for figgerin’ the amount of change from any sort of fraction of a turn can easily be done like this on most any cheap calculator:

(1/14) * (5/360) = .001” 5° of a revolution (360°)
(1/14) * (1/50) = .0014” CatShooter’s 1/50th of a turn
(1/14) * (.5/12) = .003” half an hour’s travel by the hour hand
(1/14) * (1/16) = .0045” one sixteenth of a turn
(1/14) * (1/12) = .006” 1/12th of a turn, or one hour to the next by the hour hand
(1/14) * (1/8) = .0089” 1/8th of a turn
(1/14) * (1/4) = .0179” 1/4th or a quarter turn
(1/14) * (1/2) = .0357” half a turn
(1/14) * (1/1) = .0714” one full turn, or 360°


“Proper adjustment of the full-length die will keep all dimensions within the tolerances and clearances needed for proper operation of the rifle - including maximum accuracy. Accuracy comes from consistency, and only a full-length sized case is consistently like its mates. Neck sized cases will over the course of two or three firings; not only becoming quite tight in the chamber, but will do so to varying degrees, leading to inconsistent bolt operation and inconsistent barrel harmonics. A fired case hits the inside of the chamber hard enough to initiate an element of the barrel's vibration pattern; do that inconsistently and your accuracy will suffer.”

Germán A. Salazar
http://riflemansjournal.blogspot.com/2010/06/basics-resizing-case-dimension-changes.html

I prefer some clearance on up to ~ .002" on a bolt gun.

 

[tmwinds]

I just reviewed the directions for the die and it says to screw die in until it touches case and then run it in an additional 1/8-1/4 turn. I think I had been running it in a 1/4 turn. What do I need to look for to know I am getting it adjusted correctly?

To start, turn it down until it touches the raised ram and then back it off 1/4 of a turn...

Then fire some new cases. IF you can close the bolt on the fired case with little or no resistance, than load them, and shoot them.

At some point, they may get to the point that closing the bolt is difficult. At that time, start turning the die down a teeny amount (1/50th of a turn) and try the case again, then chamber it - if it is still hard to close, turn the die down 1/50th again and repeat - keep this going until the bolt closes with just the slightest resistance, and lock the die in place.

Easy peasy

Just do what CatShooter says. You will get a better feel of the slight resistance you want if you remove the firing pin assembly. You can buy all the fancy tools you want later. You will be just fine if you follow CatShooter advise for now.

 

[Dgd6mm]

There is more then one way to skin that Cat. ;D

 

[CatShooter]

I also suggest using a Wilson case gage. The Hornady tool is OK but the Wilson is easier to use, IMO.

The Wilson gauge, or the Hornady tool will tell you nothing that will solve your problem.

You need to adjust your die so there is no space when the sized case is chambered... there is no magic tool for that.