Cracked Casings - Please help!!!

[Slamfire]

You really need a way to measure the amount you are moving that shoulder.

+1. Without the ability to measure what you are doing, you really don't know what you are doing to the case, and then the discussion rapidly drifts into philosophical arguments.

I will agree and affirm that you will be better off full length resizing your cases and setting your dies up with cartridge headspace gages. I am of the opinion that neck sizing is a very profitable fraud for the industry. In time, your cases will be over length and you will have to knock them out with a cleaning rod. Neck sized ammunition will not necessarily be interchangeable between rifles.

Having cartridge headspace gages and using them to set up your dies means ammunition will chamber and extract properly from the other rifles you own, or may own. It also means that the ammunition will chamber after multiple resizing. I am currently shooting up my oldest ammunition, just this week shot up around 80 -120 rounds of 6.5 Swede ammunition. I sized this ammunition before I purchased cartridge headspace gages. Some of this ammunition was a couple of decades ago, and had been loaded that long. I set up my sizing dies based on Swedish service rifle chambers. Size a case, put it in the rifle, see if there is resistance to closing. It turns out service rifle chambers are huge and getting those cases into this M70 required hitting the bolt handle with my palm. I believe my case lubrication was the primary reason I did not have to use a cleaning rod to knock any cases out, but, have oversized cases that are large enough, no lube in the world is going to prevent that. New cases fed in great, came out great.






These CBC cases were hard to chamber, and I had cracked case necks because the stuff had been loaded so long.



Same issue here, hard to chamber, cracked case necks, don't know if they were responsible for the nines, nines happen.

 

[Walkalong]

https://www.midwayusa.com/product/530798/rcbs-gold-medal-match-series-bushing-2-die-set

https://www.midwayusa.com/product/699314/redding-type-s-bushing-full-length-sizer-die

 

[MEHavey]

It's obvious we/the OP have a very serious headspace problem.
All other reason and/or conjecture aside, nobody blows the end of a case off like that w/o some serious room for case stretch/separation

I'm going to suggest the OP read/heed THIS very carefully.
Spend the slight amount of money for the gauge set, use it, establish the baseline, use it setting up the die each session,.... and sleep better at night.
Save your eyes, fingers, bolt face... and oh yeah... cases.




ps: I'd also run a paperclip test on all remaining cases before using them

 

[Walkalong]

ps: I'd also run a paperclip test on all remaining cases before using them

For sure.

 

[243winxb]

shoulder measurements using a 9mm casing

A 40 S&W case may give a better measurement , higher up on the shoulder. Its what i use for 30-06, 243, 308.

 

[Jim Watson]

ps: I'd also run a paperclip test on all remaining cases before using them

Post #22.
But I would not use them at all, unless measurements and trials with other brass led to correction of a fault other than weak brass.

 

[MEHavey]

If the once-fired commercial ammo cases pass the paperclip test, it only indicates that the chamber is within SAAMI Spec.
If the second firing blew the heads off, then the shoulders were grossly set back several 10's of thousandths.

Again, see this:
https://www.thehighroad.org/index.php?threads/looking-for-a-headspace-gauge.662294/#post-8202984

 

[Walkalong]

$7.00
http://www.ctstrimmer.com/case-gauges/21-case-gauge.html

 

[Nature Boy]

^^ spend the $7. End the theory and conjecture ^^

 

[243winxb]

Shipping will be more then the $7.

 

[rjs5244]

My case length gauge finally came in the mail. Out of 60 neck sized casings, no shoulder lengths were too short. 6 shoulder lengths were too long ranging from .002"-.008".

 

[jaguarxk120]

Something is still not right. Take a new case, unfired and measure it. Also the case's that measured too long, how do they chamber?

 

[Slamfire]

My case length gauge finally came in the mail. Out of 60 neck sized casings, no shoulder lengths were too short. 6 shoulder lengths were too long ranging from .002"-.008".

Did you take a fired case and drop it into the gage? Was it between Go and No Go?

If a fired case is between Go and No Go, then the rifle is mechanically correct and you are not having excessive case stretch. Then the case rupture must be due to other things.

I have seen case head ruptures that were in "processed" Scharch military surplus brass. I believe that cartridge brass was exposed to something that attacked the brass. So, find some other brass than your once fired Remington. I don't understand why there should be any problem with recently fired R_P brass, so did the brass come into contact with ammonia or some other chemicals during cleaning?

The next is how do you weigh powder, how do you calibrate your scales, and how do you deliver it to the case? When defective materials and mechanical failures are ruled out, what is left is too much powder. Pressure is exponentially proportional to powder charge weight, that is the pressure curve is exponential. If pressures are high, then too much powder.


I find the charge of 49 grains IMR 4064 not unreasonable, I recently chronographed some loads I created from 1987.

M70 30-06 24" barrel

168 R-P Core Lokt (greased) 48.0 grs IMR 4064 thrown, R-P cases CCI 200

Loaded 1-1989

13 Oct 2017 T=78 °F

Ave Vel = 2504
Std Dev = 53
ES = 167
Low = 2418
High = 2585
N = 14

Notice the high extreme spreads. Newly loaded cases are around 50 fps. This is what happens with old powder: burn rate instability. Also, old powder caused case neck cracking, old gunpowder out gasses nitric acid gas. How old the powder? Is this 1970's, 1980's, 1990's?

 

[MEHavey]

Take a new case, unfired and measure it

^^^^^THIS^^^^^
what's an unfired commercial round measure vs your once-fired/sized case?

 

[WVRJ]

I would be among the first to say headspace is the problem,and it may well be.I wonder about turning brass with a drill using steel wool to remove the burn marks.How much brass got displaced,and how hot did the brass get?How old is the brass,and how long was it loaded before it was shot?IMR 4350 in a 30-06 should be very stable,but then,4064 should be too.Interesting problem,I want to watch this one and see what it winds up being.

 

[cougar1717]

This is the lee collet neck sizer. The shell holder pushes up on the slotted sleeve that is guided by the die body. The sleeve then contacts the short tapered cylinder that compress the slots on the sleeve and compresses the neck of the brass. That compression is stopped when the inside of the neck of the brass contacts the mandrel (the mandrel also deprimes the brass). There are no adjustments on the actual sizing process. The die needs to be turned a minimum of 1 full turn after contacting the shell holder. The die can be turned in further than the 1 full turn with no effect on how this die will size. I confirmed this information with the engineers at lee precision.

OP, others have posted a lot of good info. After reading through all this, as long as you are sure that it isn't the headspace of the rifle, IMHO, it's either a bad batch of brass or you have the collet die adjusted so tightly that it has yielded the case with starting loads. Most posters want you to start over with the full-length sizing die from the Lee set and a way to compare shoulder setback - I think that is where I would start. Get rid of any case that you see is wrinkled - it's already compromised. I use a Lee collet die and have had good results with it. It's just that the collet die takes "touch" to work properly and the thing that stuck out to me about your description was that you repeated the Lee collet die adjustment instructions verbatim. I think your issue may be in the adjustment of the collet die.

If you want to try the collet die again, here is how I would go about using it:
1. With the die apart, measure the mandrel. The brass will spring back from this diameter.
2. Put the collet die in the press, extend the ram so that it just touches the bottom of the die.
3. Remember that the ram's pressure against the bottom of the die moves the collet against the mandrel (with the brass in between) and that the window between the collet being fully open and fully closed is short.
4. Make sure the case that is going in isn't wrinkled in any way - the die can't fix compromised brass.
5. Measure the inside diameter of the brass case neck before collet sizing (it may not be completely round, but it will be more than .308")
6. Adjust the collet die down incrementally about an 1/8th of a turn, put the brass in the shellholder and run it into the die.
7. Measure the inside diameter of the neck.
8. Repeat 5&6 on this setup case until there is about .0015 - .002" difference between the bullet diameter and the inside diameter of the case - your neck tension.
9. If at any time it feels like you are putting too much pressure on the ram, you probably are. It's hard to describe this as the pressure is less than what is needed for a lubed case in a full length sizing die.
10. Load a dummy round (bullet and brass only - no primer or powder) to check neck tension and OAL. It's usually loaded long so that you can measure the maximum length that your reloaded cartridge can be.
11. Test the neck tension by holding the dummy round and trying to push the bullet into the case with a piece of scrap wood. Don't try to hammer on it, but if you can budge it with hand pressure, you need more neck tension - repeat 5&6.

Good luck and hope this is helpful.