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oldandslow
05-30-2018, 09:47 PM
Greetings,

Thanks to all who provided input on the "lead-pot brass annealing" thread. The purpose of annealing is to provide longer neck and shoulder case life and more consistent neck tension. So far after 10 full power 30-06 reloads and three annealing cycles the case necks and shoulders show no pitting or cracking.

What I didn't count on is a new failure location at the lower case body, 0.5" up from the case base. I had a complete case separation and upon inspection of the other fired cases about a third of the test cases had signs of impending separation- either external grooves or bright lines all at 0.5" above the case base (see pictures).

https://i.imgur.com/PvGTNnH.jpg
https://i.imgur.com/PvGTNnH.jpg


All cases had been full length resized. Measurements of the case widths at 0.5" above the base are listed below.

1. New unfired case with FL resizing- 0.462"
2. Four times fired and FL resized- 0. 464"
3. Nine times fired and Fl resized- 0.465"
4. Ten times fired and unresized- 0.466"
5. Ten times fired and full head separation 0.466"

So it seems that despite full length resizing that the base of the case grows and once it reaches 0.465-0.466" that one gets case fatigue and failure with my particular 30-06 rifle.

It would appear that to avoid lower case body failure that I can:

1. neck-resize only (to avoid work-hardening the body)

2. just trash the cases after a set number of firings

3. measure the case widths and trash when approach 0.465"

4. do a better job of seeing the impending case failure lines
(which may be too subjective to call)

I'd be interested in other's opinions if possible.

best wishes- oldandslow

JimB..
05-30-2018, 09:52 PM
How is the head space? If you bump the shoulder a couple thou less, assuming everything still works, does this problem still develop as quickly?

plainsman456
05-30-2018, 10:58 PM
Yep i would think headspace might not be kosher.

OS OK
05-30-2018, 11:49 PM
Cut one of those cases with the shiny ring in half and see what is going on...I've heard tell that you can make a paperclip feeler gauge to feel the thinning on the inside of the shiny ring. It's a paperclip straightened out with a little 1/4" x 90* bend in the end.
I wouldn't full length resize anyway for a bolt gun...just neck size or just bump the shoulder back a couple thousandths so they close in the rifle without undue pressure on the bolt.

mehavey
06-02-2018, 04:38 AM
All cases had been full length resized.All normal chambers have a acceptable headspace range (10 thousandths in the case of an `06). And unless you have MIN headspace, Full-Length resizing sets the shoulder back to the point that repeated firing/stretching is going to cause head separation... period.

- Get yourself a Hornady Case Headspace Compatorator (https://www.amazon.com/Hornady-HK66-Lock-N-Load-Headspace-Gauge/dp/B000PD5VN8)
- Resize a case in small increments to the point that it will juuuuuust barely chamber/bolt close w/o force.
- Measure the case headspace dimension and subtract 0.002" -- Write it down
- Resize to that measurement for that rifle from now on.

As an additional case stretch preventer, polish the cases and/or leave a touch of case lube on them.
Any added bolt thrust is negligible relative to a mirror-polished case.

McFred
06-02-2018, 09:20 AM
You only need to FL size such that your cartridges fit your chamber reliably. A hard press cam-over might meet the minimum SAAMI headspace spec, but that is not required for a dedicated set of brass for one rifle.

To minimize eventual case-head separations, I went to neck sizing until the cases no longer permit easily closing the bolt. Then I body size with a die that I can control the shoulder bump. Redding has a set of graduated shell holders that will allow you to precisely control shoulder bump with a hard cam-over on a single stage press.

Between a strict neck-annealing, neck-sizing and a .0015" shoulder bumping regimen, I get a lot more full pressure firings on rifle brass before the case head separation tell-tale shows. On some brass cases I get more than thirty 60ksi reloads before I get cracked necks.

ShooterAZ
06-02-2018, 10:57 AM
It does sound like a headspace issue, likely shoulder bump. Another "work around" on this is to use the RCBS X-Die. Used correctly, it practically eliminates case stretch. I have got more than 20 firings in my 30-06 cases, with both jacketed and cast, with no trimming and no stretch. It's a little spendy, but worth it in my opinion. Neck sizing is another option, but sooner or later you will still need to FL size and trim. Using the X-Die your cases will last a long, long time with absolutely minimal trimming.

https://www.midwayusa.com/product/1011737083/rcbs-x-die-full-length-sizer-die

higgins
06-02-2018, 11:04 PM
I have dedicated FL sizing dies for a couple of rifles that will allow the bolt face to just kiss the case as the bolt handle seats, as described in mehavey's post above. Die sets for common cartridges like 30/06 come up frequently on sale boards and can be had for cheap, especially if they have a little external rust or damage. The good news is that the sizing lube protects in inside of the sizing die in most cases even if the outside has light rust.

oldandslow
06-05-2018, 06:58 AM
Greetings,

Thanks for all the useful tips. What started out as a simple way to extend case life by annealing is morphing into a time and money intensive chore if I start shoulder bumping and neck sizing. It may not be worth the effort when I can buy easily obtainable 30-06 cases. The results so far allow me to extend case life from approximately 5 firings with full-length resizing (until I get neck cracking) and no annealing to 8-9 firings with annealing every three firings until I get case head separations. That's a lot of work for three extra firings with annealing. I've just moved the case failure location from the necks to the case head-body junction with annealing.

That said- reloading hasn't always been about the easiest way to do things. I've started researching Forster and Redding shoulder and neck sizing dies and may make the purchase when I'm having a weak moment.

thanks again- oldandslow

mehavey
06-05-2018, 07:39 AM
Annealing had nothing to do with the the case separation.
That was all due to over re-sizing.

Get the Case Headspace Comparator and Bump the shoulder 0.001"-0.002" as noted above, anneal every 8-10 firings (not every 3).

With medium loading/bolt action you can get 2-dozen cycles out of a case.

MostlyLeverGuns
06-05-2018, 09:40 AM
I use the Redding Competition shellholders +.002 - +.010 to determine full-length sizing needed for each rifle. You can carefully adjust a full-length size die to minimize sizing. AT one time I would set-up a full-length size die for each rifle, minimizing required case sizing. I found with the Rdding shellholders many rifles readily accept +.006 sizing and a few +.008. I haven't found a rifle that needed cases sized more than +.004 so most standard shellholders and 'standard dies' set case shoulders back 'excessively' shortening case life. I also have the 'practice' loads sized +.008 that chamber with maybe a touch of resistance for half of the cases, I then switch to a +.006 for easy chambering hunting cartridges. When hunting, I run every cartridge carried through the magazine and chamber for function. Just one rifle in caliber adjust the die, more than one use the Redding shellholders, the Redding shellholder does 'square' the case with die compared to backing off the die from the shellholder. I've gained 4-5 full-power loadings per case 4-5 Savage 99's in 300 Savage, same for another half dozen Savage 99's I play with. I do keep cartridges separate for each rifle.

MT Gianni
06-06-2018, 01:14 AM
Get a cheap drill motor and an adaptor to go to a 1/4" drive socket. Buy a 1/2" deep socket in 1/4" drive and place a case in it. Anneal by heating the top 1/3 or less of the case in a lp torch flame until it is no deeper in color than a dull orange. Invert the drill causing the case to fall into a bucket of water. Repeat the test again with cases that have and have not been annealed this way. If you are depending on a sight process where you cannot see the experiment you cannot duplicate it.
Along with the others I believe this is a sizing problem from the location of the break rather than an annealing problem.

oldandslow
06-07-2018, 03:32 AM
Greetings,

Thanks for all the input.

Mehavey- I wasn't thinking that the lead-pot annealing was directly causing the case-head separation but that with the longer case life (from 5 firings without annealing due to neck splitting) this allowed the case to fail in a different location.

So it looks like I have several options to decrease my overly generous headspace given by the full length sizing dies.

1. I can measure the difference in headspace between a fired and unfired case with a Hornady headspace comparator and bump the shoulders back 0.002" with a Forster neck-bump die ( price $80-100) and then neck size.

2. I could neck size only the fired cases and then full length size them when they become difficult to chamber in the rifle.

3. I could send three fired and unresized cases to "whiddengunworks" who will make a custom full-length sizing die for $118.

I'm thinking there may be another option- if I measure the excess headspace can I raise my RCBS full-length sizing die from its present cam-over position to a higher position where it will just bump the shoulder back 0.002"? This would save me from spending several hundred dollars on new dies and accessories.

thanks to all- oldandslow

OS OK
06-07-2018, 09:53 AM
Greetings,

Thanks for all the input.

Mehavey- I wasn't thinking that the lead-pot annealing was directly causing the case-head separation but that with the longer case life (from 5 firings without annealing due to neck splitting) this allowed the case to fail in a different location.

So it looks like I have several options to decrease my overly generous headspace given by the full length sizing dies.

1. I can measure the difference in headspace between a fired and unfired case with a Hornady headspace comparator and bump the shoulders back 0.002" with a Forster neck-bump die ( price $80-100) and then neck size.

2. I could neck size only the fired cases and then full length size them when they become difficult to chamber in the rifle.

3. I could send three fired and unresized cases to "whiddengunworks" who will make a custom full-length sizing die for $118.

I'm thinking there may be another option- if I measure the excess headspace can I raise my RCBS full-length sizing die from its present cam-over position to a higher position where it will just bump the shoulder back 0.002"? This would save me from spending several hundred dollars on new dies and accessories.

thanks to all- oldandslow

Give this old gunsmith a listen . . . https://www.youtube.com/watch?v=yDE84oOuz0c

Elkins45
06-07-2018, 11:01 AM
I don’t believe I saw where you mentioned the kind of rifle you are loading them for. Unless you’re shooting in an autoloader then you really should consider turning your sizing die out half a turn or so until the bolt closes with a small bit of resistance on an empty case. See if that doesn’t solve the problem.

country gent
06-07-2018, 12:17 PM
It is SOP for NRA high power shooters to size so that the shoulder is bumped back .002-.003 from fired dimensions. This gives clearance for easy functioning and feeding but cuts down greatly on the stretching that happens. When I rebarreled I would make a simple gage with the reamer of shoulder and neck 1" long. This gave me a "gage" to use to measure thee shoulder and set back when sizing. It wasn't an actual measurement of size but a comparative measurement. IE if fired cases average 1.570 with the gage then I set the sizing die to size to 1.567 - 1.568 measured with the gage.
I also think the semi autos speed up the head separation issue due to the stronger faster extraction. Garands and M1As/M14s can get pretty strong extraction cycles as can the ARs.

AS mentioned above a paper clip can be used to feel the groove inside the case. I file a point on the end and then bend 90* 3/16"-1/4" end. This will catch in the groove. A bore scope can be used to see the actual groove. Another way though it is destructive to the case is to cut the case inn half length wise so you can see the interal groove, pick a case with a very visable ring. You will be surprised at how heavy the groove is in the case. clean up the saw cut with a fine file and sand paper and you can see how this it is also.

mehavey
06-08-2018, 11:15 PM
if I measure the excess headspace can I raise my RCBS full-length
sizing die from its present cam-over position to a higher position
where it will just bump the shoulder back 0.002"Yes, that is exactly our recommendation.

osteodoc08
06-09-2018, 06:23 PM
Larry Gibson has a nice article on the X Die and his use in the 308. Do a search and you’ll find lots of data he collected and put together