Someone help me understand something:
Assumptions: Head Spacing is important because it effectively sets the primer depth and if the case moves in the chamber that effects accuracy? Breech thrust is the case head pushing back against the face of the frame where the firing pin protrudes, and the under lug pushes against the hinge pin to keep things in place?
If that is the case, why is it when I fire a revolver that the case heads are not pushed up against the frame, and do not appear to have moved at all, and in many cases are snugged up inside of the cylinder? I'm missing something somewhere....
Kendall
HEAD SPACE is haw a cartridge fits in its chamber. The primer backing out is sometimes a telltale sign of a head space problem, but not always. Straight walled cases react entirely differently than bottle-necked cases. Also anything below a 40-45,000 CUP threshold are entirely different then anything above this.
The brass is very "springie" (tech term.
) and upon firing becomes tightly pressed to the walls of the chamber. Now the primer, if sufficient pressures exist, isn't held in place as tightly and will be pushed back to the recoil shield or breech face. Then as pressures drop the brass releases, there is still enough pressure to push the case back, re-seating the primer. Now excessive pressures and very lite pressures can entirely change things and give wildly false results.
Primer powdered, wax bullet loads are a good analogy of protruding primers in a revolver. BUT simply drill the flash hole to say 1/8" and the protruding primers disappear!! GO FIGURE!!!
CW
