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Most welcome - I should have noted, I use the same proceedure of case forming and fireforming for my Oberndorf 9.3x62.

I also learned a long time ago, to use a decent, normal load for fireforming - ie: a moderate to just max (if worked up prior) for fireforming. The pressure generated will actually be slightly less than the same load in a formed case.

This is due to the absorbsion of energy in actually forming the brass to fit at the shoulder and body. Do it right the first time as if it takes repeated shots to form the shoulders sharply, there will be stretching at the web - exactly what you do not want.

The closer the case is to fitting tightly, both sides and shoulder, as in my 9.3x57 picture expample, the less will be the pressure and velocity drop once the brass is formed. In this round and my .375/06IMP, the difference is only a 34fps drop. Typically, with this method of case forming, you can sight in and hunt with ammo the first time it is load. By this I mean, you can hunt with fireforming loads as long as you don't mind a bit of 'crush' when chanbering.

Further, if you run all your ammo for fireforming through the action first, chambering and closing the bolt completely (crush fit), they will then chamber more easily the second time as the shoulder as the act of chambering them has moved the shoulder to exactly fit the chamber, instead having to move 'some' brass as the first time they are chambered.

If the cases always chamber with a bit of 'feel' on closing the bolt, the headspace of the brass will remain unchanged. This is why I never touch the shoulder. I've never had to 'bump' a shoulder. To me, having to 'bump' a shoulder as the bench rest shooters say, means the elasticity of the brass has been exceeded by the load developing too much pressure. They typically use what we call an excessive load - right at the hairy edge of case body extrusion.

If the bolt closes sloppily as with a factory case (normally up to .007" slop depending on the chamber), I'd not fire it until I checked it's headspace.

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Daryl

"a gun without hammers is like a Spaniel without ears" King George V

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