[Sky Zero]

Originally Posted by Rick W.

I am not overly sure of what is causing the marks on the case from here.

Likewise, I am not overly sure, how brass will mar steel but I do not get out much.

The extractor that resides in the breechblock only has so much reach up the case, wants to run over the rim and lock into the rim recess of the case during charging. If the brass shavings are coming from there, looks like the rims would show the wear(scratches at least).

One might take a small file and mark the rim with a smallish cut, then put that cut straight up before firing in single shot mode. That way you would have an angular reference as a clue.

I reckon it is possible for the fired case to be marked by the sharp edge(taper crimp) of the next round in the magazine, and possibly by the ejector. Just a guess on my part. Perhaps the ejector is kicking the spent case hard to the left onto the receiver fork?

The 9mmx19 is a slightly tapererd rimless case that headspaces on the case mouth. The original crimps in reloading were so called rolled crimps, such that the front of the case mouth was actually rolled into the bullet by the crimping/seating die. The taper crimp dies actually compress the case around the bullet completely, kinda a complete squeeze, rather than just at the case mouth.

It is easy to overdo the roll crimp and effect headspace, lots of leverage in today's presses. The taper crimp can be overdone too, but a bit harder to do because of dimensional stops, but leaves a nice squarish face to headspace on. Most that do the roll crimp on these cases use only a smallish amount of roll, and the headspace is off the very slightly rolled edge. Both methods will work nicely, appropriately applied.

One finds the roll crimp moreso in the rimmed cases.

One has to have to have some crimp, from whatever type of method, just to keep the bullet from going down the case and reducing the powder cavity(higher pressures). One might note that an overly smallish expander can provide fair amount of bullet holding power on its own but can effect accuracy especially with lead bullets(lead shaving on seating).

The holdopen deal can be a puzzler at times. The spring on the holdopen tries to keep the face of the holdopen in its cavity at all times. If the holdopen lead spring is weak, then the holdopen can bounce upward and catch the breechblock early. If so, one would think that the holdopen issue would show up somewhat randomly with reference to the number of cartridges still in the magazine.

The other issue is in the magazine itself. How high does the new magazines sit in the frame. The other is the size of the magazine loading button on the side, ie diameter of said button.

One can take the one grip off and watch the things work on the holdopen versus the magazine button. The purpose of the button is to mechanically lift the holdopen up against the will of the hold open spring to catch the breechblock appropriately.

I notice some wear on the ramps; may just be the picture.

thank you for the crimping info! Now I unerstand when people are talking about it haha. Appreciate it!