I have some photogenic cartridge cases. I love wildcats, but I don't like other peoples' screw-ups but I have both in a project I've taken on.
The belted 300 Weatherby case necked down to accept .264" bullets or the 6.5-300 WBY or originally the 6.5 Wright-Hoyer, which wasn't a WBY double ogee shoulder, but this beauty is. I received this gun with some "fireformed" brass and some new brass. Some loaded ammo and some formed brass, (and a couple of oops! cases that showed that the previous loader was in trouble.) along with an RCBS two die set of reloading dies and a two die set of case forming dies. This is about $450 of dies.
Well the "fireformed" cases were fireformed in a W-H chamber and were originally 300 H&H brass and they didn't fit the chamber of the Weatherby. The formed cases had the shoulder pushed too far back in the #2 case forming die, and they didn't fit the chamber. The sizer die was well matched to the chamber but the form dies are more generic and "over formed" the shoulder. Firing one of these, with a moderate charge and a 100 grain bullet, resulted in a seperated case. The belted end came out easily but the front end of this big case stayed in the chamber of the rebarrelled Ruger #1. I use an easy-out bolt extractor to get these out and it doesn't usually take much effort just the right diameter tool.
Back to plan B. I pulled the bullets from the loaded rounds and dumped the powder and the holofil sleeping bag insulation from the cases. I then loaded the cases with about 70 grains of RL-25. That's the powder that was in the hopper and it was of the correct type to fire form with. I like to use the course extruded powder. It is quite hard and about the texture of creek gravel. I then load this over magnum primer without a bullet. Point the rifle upward, chamber a round and fire. This went on for forty cases on Sunday.
The heavy charge of powder is launced down the case and slams into the shoulder of the case and pushes it out agains the chamber. As the charge is ignited, it bushes back against the case head (recoil) and pulls the whole case back agains the recoil face of the rifle. If there was a bullet in the case it would have buit pressure up and pressed the case against the side wall then pushed back enough against the case head to stretch the case just ahead of the belt causing a thin ring of brass at this point. This will surely result in a seperated case at the next firing. (It had just done that with the the only shot of the day Saturday) This technique is a modification of Ken Howells inert material (corn meal) fireforming. It cannot really be called inert even though most of the powder is not ignited, it is merely launched down the tube. This hard extruded powder works better than corn meal in cases that have not been annealed (softened). This is a simple and expedient way to form cases and requires only the expense of powder and primer and a good clean up after. Anyway I now have some pretty nice formfitted cases for this wilder than normal cat and will rely on Beartooths expertese and experience with this caliber (re: his 257-300 Weatherby) for more appropriate load data with bullets this time.
These rounds are quite loud and there is a significant recoil form the load. This is for those who don't think the powder charge should be in my recoil equation. The load of powder generates Newton 3rd law recoil and the exiting gases generate Bill Lear recoil. I love this job.