Got a head-scratcher going on.

by Hoot , Diversityville, Liberal-sota, Thursday, November 13, 2014, 08:05 (3668 days ago)
edited by Hoot, Thursday, November 13, 2014, 08:11

A while back, I picked up a sporterized 1888 Commission rifle which has gone through the arsenal refurbishing to accept the .323" 8x57 cartridge. I have a couple hundred 8mm cast bullets and my thought was to make this a cast projectile flinger. This thought was in deference to both the age of the rifle as well as the (probable--haven't slugged it yet) ~.318" bore.

So, armed with 16 cases loaded with a modest charge of 4198, we head to the range. I managed to get off exactly 1 shot (did hit the paper) only to find the extractor will not remove the fired case. Of course, a well prepared shooter would reach into his kit and pull out a cleaning rod and poke it out. Me? Yeah, I cased it up and brought it home as that issue was not anticipated nor even considered.

At home, the fired case popped out readily and the extraction issue was immediately evident. The spent primer was about 0.100" proud of the rim, which pushes the rim too far out to be grabbed by the extractor. OK, the charge was too modest then. The remaining cartridges were disassembled and set aside.

Yesterday, I went to load the cases for another go at it. Going to bump the charge a bit--there's plenty of room to move. But first, let's examine the fired case relative to a full length sized, unfired one and see if there is anything odd going on in the chamber.

Much to my surprise, the fired case is shorter by approximately how far the primer has extruded. Overall case length and as near as I can measure to the body-shoulder and neck-shoulder junctions are all that same ~0.100" short. Body and neck diameters are not significantly different fired to unfired...about what I'd expect from firing.

Since that discovery, I have been trying to understand what might have happened to shrink that case but it hasn't come to me yet.

Any thoughts?

Thank you,
Hoot