by w30wcf » Wed Nov 06, 2013 10:14 pm
Ok, finally had a chance to test the .44-40 ....... a few days later than anticipated. Life gets in the way sometimes .......
Anyway, the test indicates that the case head did not make contact with the bolt.
I used 2 cases with thinned rims (front) allowing for .015" headspace.
I seated the primers to stand .012" proud of the base of the case then applied 2 small clay pads on either side of the primer to the same .012" thickness.
Cases were loaded with 6.5 / Trail Boss / 215 gr cast bullet. Pressure 13,000 CUP or thereabouts.
Result:
Primer protruding .010" . Clay pads the same. No evidence that the case head touched the bolt since the small clay pads were not distorted as they would have been if the case head touched the bolt face.
I will say that the cases used were not full length sized. Just neck sized as I do all my .44-40's with a special die.
I'll post a pic in the next day or so.
by w30wcf » Mon Nov 11, 2013 11:59 am
I had added a piece of scotch tape over the case head to keep the clay from possible sticking to the bolt face.
I would expect that as pressures would increase, the case head would eventually overcome the primer thrust and reseat the primer but this is specifically a test of low / standard SAMMI pressure for the .44-40......