Thread: Incipient head seperation and a possible mitigation method.

I should also have explained that I set the resizing high for the 8mm neck expansion process and also for partial down sizing to 308 at the final stage. Same with bullet seating die so ad not to accidentally stuff up the new shoulder.

Originally Posted by Dicko

I just adjust my fls die so the case fits in the chamber with a soft touch required on the bolt.

My cases last as long as my unbelted 06, .270, .308 brass.

Ignore the belt and size to the chamber or have I missed something?


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The issue is more pronounced in the belted cases due to the hard spot where the belt finishes becoming a natural place for the thinning to start. Once it has started, the flow is concentrated in the same place so tends to show the cracking earlier than brass without the stress riser where the case wall abruptly narrows at the place the belt stops.

Lee collet dies are perfect for this. I use them for .303 and have got 11 or 12 reloads and counting. Some people only get 3 reloads when full length sizing.

The idea is soley for first firing of virgin brass.

My brass (7RM and .300WM) last well. Normally case life end due to cracking necks, loose primer pockets.

Be interesting to see how much of a issue it is with loaders more broadly?


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Originally Posted by Dicko

I just adjust my fls die so the case fits in the chamber with a soft touch required on the bolt.

My cases last as long as my unbelted 06, .270, .308 brass.

Ignore the belt and size to the chamber or have I missed something?


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This has always been my approach as well regardless of belt or non belted case, in belted cases I have found that you will get decent brass life providing you don’t hot rod the shit out of your load. Over pressure loads will kill brass in 1 firing as I found out recently, I was given a bunch of once fired Sako rem mag brass by a mate and it had been loaded so hot the cases had expanded just above the belt and could not be sized back down.
I've also seen rem mag brass ruined in 2x firings by over sizing (bumping the shoulder too far back).

In short forget the belt, bump your shoulder till your brass just chambers and don't exceed pressure. Your brass will last fine, also annealing helps increase case life as well, I anneal after every firing with magnum cases.

Originally Posted by dannyb

I was given a bunch of once fired Sako rem mag brass by a mate and it had been loaded so hot the cases had expanded just above the belt and could not be sized back down.

Some Sako & Tikka chambers are so big, it doesn't take much of a hot load to experience that problem especially on the third or fourth firing once the brass starts to get hard

Once sized it can develop a double belt & brass shavings, this can easily make it impossible to use in another rifle, especially if it has a nice chamber

Even once fired secondhand brass can be a lottery in any cartridge, especially belted magnums

Originally Posted by Woody

Yes, i've of that Larry Willis die and gave it some thought. My rifle is 308 Norma mag from 1960s era and the only brass is from Norma. Howevet, I figured I may ad well try a low cost solution as an experiment. The rifle shoots sub moa so well worth looking at extending case life. Thanks for yr input though.

Greetings @Woody,
Have not heard of the .308 Norma Mag for a while. Some time ago my friend had developed a burning desire for a .300 H&H but could not find anyone with a reamer but found someone with a .308 Norma Mag one. He had a Parker Hale magnum action and had scrounged up an old .308 target barrel so the Norma would need to be it. He also scrounged up some cases which unfortunately would not chamber even after FL sizing. The tight spot as you will likely know was right in front of the belt. Bugger. This was in the days when bulge buster kits were not available so after a bit of head scratching a stripped .300 Win Mag die was tried. This was better but not much so the next step was to size the case with the case on top of the shell holder which allowed it to enter the die just that little bit more. The cases needed to be tapped out of the die with a rod but it worked a treat.
Regards Grandpamac.

Yes. Most of the older belted magnums can be formed from the HH parent case. There were certainly variations in the american made reamers in the old days when they converted 30-06 actions to 7*61 and 308 Norma mag nums.

maybe you should neck size only less stress on brass i run pmc brass in 7RM havent had any brass issues so far