30.06 case failure after 3 reloads - it pays to inspect brass closely

[zambezi]

if the down stroke on resizing process has been hard as long as you've reloaded these cases

Re-read my post: the down stroke is easy. Lifting the arm up again [i.e. drawing the expander ball up through the neck] is the hard part. And that is consistent with where/when I now see case damage: it is a split which is initiating where neck first meets shoulders, which is where expander would first jam into neck as it rises back up through the case.

not knowing your annealing process maybe it's not part of solution but part of problem

I brought my OCD to this too and have rehearsed best method I can achieve using propane torch. That said, the AMP chap is quoted in that thread as saying you cannot "over-anneal" brass. You can clearly make an error by annealing too far toward the case head, but he states that were you to anneal the neck twice [for instance] it remains as annealed after second run as it was after first.

I know my annealing process is conferring ductility as there is a clear difference in how easily a fired piece of brass and an annealed piece of brass are sized.

Are you shooting dry or lubed necks?

Dry

What about pressure signs..., it was that brittle and the primers were always flat or blown.

I use two loads. The 180gr load does produce slightly flatter primers [no blow outs], but no difficulty extracting nor any head swipe marks.

 

[jthyttin]

Re-read my post: the down stroke is easy. Lifting the arm up again [i.e. drawing the expander ball up through the neck] is the hard part.

To clarify:

Sorry, I made the same mistake in post #10. Whole time I was meaning the downward motion of "piston" in press i.e. up-stroke of handle.

Cannot really appeal to being non-native speaker, whole time I knew what I wrote but somehow mixed it up...

 

[Jagged77]

So then what might be issue? Running out of ideas.

My guess, potential over annealing and lack of case lube in the neck causing damage resulting in the failures you’re seeing in that area.

 

[Ginc]

Re-read my post: the down stroke is easy. Lifting the arm up again [i.e. drawing the expander ball up through the neck] is the hard part.

I experienced the same issue with 30-06Spr S&B brass and Hornady FL die. Switched to Lee FL die and problem solved! Hornady die has tighter neck.

 

[JohnCZ]

I experienced the same issue with 30-06Spr S&B brass and Hornady FL die. Switched to Lee FL die and problem solved! Hornady die has tighter neck.

I am not a fan of those Hornady dies, tried them a couple of times now and always return to RCBS. (Plus the die box is stupid).

 

[JohnCZ]

Re-read my post: the down stroke is easy. Lifting the arm up again [i.e. drawing the expander ball up through the neck] is the hard part. And that is consistent with where/when I now see case damage: it is a split which is initiating where neck first meets shoulders, which is where expander would first jam into neck as it rises back up through the case.



I brought my OCD to this too and have rehearsed best method I can achieve using propane torch. That said, the AMP chap is quoted in that thread as saying you cannot "over-anneal" brass. You can clearly make an error by annealing too far toward the case head, but he states that were you to anneal the neck twice [for instance] it remains as annealed after second run as it was after first.

I know my annealing process is conferring ductility as there is a clear difference in how easily a fired piece of brass and an annealed piece of brass are sized.



Dry




I use two loads. The 180gr load does produce slightly flatter primers [no blow outs], but no difficulty extracting nor any head swipe marks.

Maybe try some dry lube (graphite works well)

 

[zambezi]

always return to RCBS

My die is F/L RCBS [part 14801] . And it is difficult to lift press arm. So this die is definitely swageing neck inward pretty far/hard before expander ball sets ID by pushing back out again.

As I said, my Redding die set is much easier to operate on 6.5x55mm Sako brass. So, same maker's brass, but a more sympathetic approach to neck sizing. I think this is my direction of travel from here.

 

[zambezi]

I decided to recheck the cases with borescope lest incipient failure is masked on the outside of the cases. All good but expander ball's raking signature is very evident too.

And, for completeness, herewith image of clean Sako 30.06 rifle chamber .

 

[Laurie]

the down stroke is easy. Lifting the arm up again [i.e. drawing the expander ball up through the neck] is the hard part

Neck expansion in a conventional sizer die is a brutal process, especially if the inside of the case-neck isn't lubed. Allied to heavy / over-downwards sizing which many standard factory dies impart, neck brass is massively stressed reducing its life. I measured the various dimensional changes through the firing / sizing / bullet seating cycle on Lapua 308 Win brass sized in a Lee die and fired in an FN Special Police Rifle, that allegedly had a 'tight' chamber and it added up to some 44 thou' total movement. For many, many years now I have never sized a case without lubing the inside neck surfaces, also normally use mandrel expanders (cases still lubed) which impart far less stress as well as reducing case-neck runout. (Or the Lee Collet neck-sizer in conjunction with a Redding 'body die' to get the full-length size.)

Brass alloy quality and sizing kit dimensions aside, these failing 30-06 cases may also have unusually thin necks. Without a tubing/case-neck micrometer, the way to ascertain if this applies is to measure the O/D of the neck on a loaded round and compare the reading against another from a different make of case. Back in the 1980s my local gunshop sold a large batch of Norma 150gn PSP 308 Win ammunition at an absolute bargain price, cheaper than the primer / powder / bullet cost for handloading. The factory had turned out excessively light/thin cases weighing some 160gn (compared to 175 and up as the norm) with necks that were 11-12 thou' thickness (compared to 15 for Lapua). Fired in run of the mill (slack!) factory sporting rifle chambers of that era, these cases produced small neck splits after at most two or three firings/reloadings. As Boxer-prime 308 brass was scarce / expensive in those days, many purchasers of factory ammo only did so on the basis of a decent life involving multiple reloads. Parker-Hale the then UK Norma distributor withdrew this production lot as a result of the complaints and sold it all to York Guns very cheap on the basis of it being unsuitable for reloading. I bought 600 rounds and pulled most of them at the time, since using the cases in match rifles with tight (minimum SAAMI) chambers and sized /expanded as described above. I'm still loading the final 50 or 100 as 308s (despite having also necked many down to 7mm-08) and have never suffered a neck split despite multiple firings.

 

[zambezi]

Neck expansion in a conventional sizer die is a brutal process, especially if the inside of the case-neck isn't lubed. Allied to heavy / over-downwards sizing which many standard factory dies impart, neck brass is massively stressed reducing its life. I measured the various dimensional changes through the firing / sizing / bullet seating cycle on Lapua 308 Win brass sized in a Lee die and fired in an FN Special Police Rifle, that allegedly had a 'tight' chamber and it added up to some 44 thou' total movement. For many, many years now I have never sized a case without lubing the inside neck surfaces, also normally use mandrel expanders (cases still lubed) which impart far less stress as well as reducing case-neck runout. (Or the Lee Collet neck-sizer in conjunction with a Redding 'body die' to get the full-length size.)

Brass alloy quality and sizing kit dimensions aside, these failing 30-06 cases may also have unusually thin necks. Without a tubing/case-neck micrometer, the way to ascertain if this applies is to measure the O/D of the neck on a loaded round and compare the reading against another from a different make of case. Back in the 1980s my local gunshop sold a large batch of Norma 150gn PSP 308 Win ammunition at an absolute bargain price, cheaper than the primer / powder / bullet cost for handloading. The factory had turned out excessively light/thin cases weighing some 160gn (compared to 175 and up as the norm) with necks that were 11-12 thou' thickness (compared to 15 for Lapua). Fired in run of the mill (slack!) factory sporting rifle chambers of that era, these cases produced small neck splits after at most two or three firings/reloadings. As Boxer-prime 308 brass was scarce / expensive in those days, many purchasers of factory ammo only did so on the basis of a decent life involving multiple reloads. Parker-Hale the then UK Norma distributor withdrew this production lot as a result of the complaints and sold it all to York Guns very cheap on the basis of it being unsuitable for reloading. I bought 600 rounds and pulled most of them at the time, since using the cases in match rifles with tight (minimum SAAMI) chambers and sized /expanded as described above. I'm still loading the final 50 or 100 as 308s (despite having also necked many down to 7mm-08) and have never suffered a neck split despite multiple firings.

Thanks Laurie. That is a very comprehensive overview.

The Sako brass is definitely thinner than the Lapua. I compared 22 rounds assembled using 3x fired Sako brass and there exists a range of neck OD values between 0.333" and 0.335. Whereas sample Lapua dummy rounds using unfired brass are all sitting at .337".

Could you suggest a mandrel-type expander I might buy?

 

[JohnCZ]

Thanks Laurie. That is a very comprehensive overview.

The Sako brass is definitely thinner than the Lapua. I compared 22 rounds assembled using 3x fired Sako brass and there exists a range of neck OD values between 0.333" and 0.335. Whereas sample Lapua dummy rounds using unfired brass are all sitting at .337".

Could you suggest a mandrel-type expander I might buy?

Sinclair neck expander mandrel (0.002"), works a treat and provides great runout too.

 

[zambezi]

Decision made. I have bought the Lee Ultimate dies. Collet type neck sizer. Should be gentler than the RCBS dies...

 

[cjm1066]

Had some Winchester factory ammo, perhaps 5% split neck on first reload, rest lasted for years and many many reloads.

 

[phaedra]

One thing springs to mind, are you re-sizing after annealing?

This seems to be the current preferred method for getting the correct amount of stress relief for the most consistent neck tension.

There was a very detailed video (I think by AMP) posted somewhere showing the diffence between annealing then sizing and sizing then annealing.

This is what they say,
If, as we recommend, annealing is done every reload, the brass is always soft enough in the neck and shoulder to resize accurately either before or after annealing. We have, however recorded consistently more unifor hardness test results by annealing before resizing, and we therefore recommend that sequence.

 

[zambezi]

are you re-sizing after annealing?

Yes.

That is now my preferred sequence: de-prime, anneal, ultrasound clean, primer pocket brush, bump/resize case depending on cartridge, trim, chamfer.