Neck tension/how much?

[Hayfield]

I've been fooling around w/a Mosin Nagant the last few days. I have no dies for it yet so I've been using other dies to load the rounds. 303 collet die w/.310 and .3085 mandrills for neck sizing. 30-06 for seating just to get me started and get some brass formed. Slugged the bore and measured sized bullets closely as well as measuring the fired brass. Twice fired brass opens to exactly .311. Bullet is sized to .311...say75, not quite .312 anyway. Resize neck w/.310 mandrill and load and seat; bullet drops all the way. Resize neck to .3085 and bullet seats fine w/little or no shaving. So......I'm figuring 3 & 1/2 thou neck tension. Sound OK? Or is that too much? What's it supposed to be? Gun shoots great with it and a 314299/LLA. No crimp by the way.

[1Shirt]

If it works for you, don't fix it! 1Shirt!:coffee: :coffee:

[44man]

The actual amount of tension is not real important. What counts is that every case is the same. Much harder to figure.

[Buckshot]

...............How much effect your M die has, or the size die, is dependant upon how hard/brittle (or soft/recently annealed) the caseneck is.

A freshly annealed caseneck sized in a Lee collet die will drag on the de-capper pin all the way down. A case that has been re-sized and fired several times has been work hardened enough so that the caseneck no longer drags. Although sized, the casemouth will now be a thousandth or more larger then the de-capping stem. Springback, or workhardening is the culprit.

................Buckshot

[44man]

Yep, shoot one annealed case and one hard one and you will get two different points of impact.