My question is are these rounds safe to shoot?
As long as the powder charge is not over pressure, you won't blow up your rifle.
Here is an image of a case gage, these are extremely helpful in setting up sizing dies. This one has a cut out so you can see what is going on. Of note, if the case neck protrudes up into the throat area, that is dangerous. If the case neck is pinched by the throat, that will pinch the bullet, and that will raise pressures. Before I learned that the first firing of any cartridge results in the greatest case length expansion; I assumed I could size several times before the cases needed trimming. I was wrong, this resulted in blown primers and excessive pressures because the case neck was pinched, as it protruded into the throat. If you notice, I have lots of clearance between the throat and my case neck. Trim length is a safety consideration.
I am of the opinion that pushing the shoulder back about 0.003" each time when full length resizing, is desirable. I am of the opinion that one of the most important considerations in a magazine fed, or even a single shot fireman, is the ability to chamber and extract a round. Not everyone sees it this way, particularly Hatcherites and Ackleyites, but I want the fired case to extract. Those knuckleheads want the maximum case to chamber friction, actually believing that the case is supposed to cling to the pores of the chamber, flow into the cracks, sort of like ivy on a brick wall. I want the case to come off the chamber walls without any clinging, or crack flowing at all. Having clearance between the case and chamber before firing, will likely lead to a clearance after firing, assuming the cartridge is not over pressure. You can more or less see this in this diagram.
If you start with a crush fit case, after firing, you are likely to have a stuck case. While this is not "dangerous" in terms of pressure, it does convert your magazine fed repeating rifle into a magazine fed, single shot. Probably requiring a ram rod to extract the case. I noticed the range tower at CMP Talladega had a cleaning rod, enough shooters, like myself, had a stuck case, and for got their cleaning rod. I usually have one in my scope stand, but I did not bring that scope stand that day. I cannot count the number of shooters, who during a rifle match, needed that cleaning rod. because they had a stuck case.
