:-D
A personal opinion only...
First of all, my apologies to anyone out there that really likes this particular cartridge. I think it's a piece of crap!
I reloaded this for a "friend" who had purchased one of those Thompson Center Contenders in this God-forsaken caliber.
Why he couldn't pick a cartridge that had factory brass available for it, I'll never know. Why I accepted his challenge to load for this abomination, I'll never know!
First step was to get a bunch of .30-30 Remington brass together. Then came the running of that brass through a set of RCBS full-length resizing dies, in several distinct steps, AT 1/16TH OF A TURN OF THE DIE BETWEEN EACH STEP, so as to not crumble or crush the cases, or screw-up the headspace!
After each adjustment of the sizing die it was necessary to get an RCBS trim die, and a damn good hacksaw blade, and cut off a mile-and-a-half of excess neck brass. Naturally, it was then necessary to file the edges fairly smooth with one file, then apply another finer file to get all the burrs out.
Try the case in the Thompson to see if the action closed, and when it didn't, run the brass through the resizing die, turned down another 1/16th of a turn, saw off the excess, file the edges twice, and do it all over again ... until the action closed!
And the case forming story goes on...the final steps were to chamfer the inside and outside edges of the cases.
All this work, and not a single grain of powder was dropped...I had cuts, bruises and calluses on my poor young hands!
At the time I did this, there was extremely limited loading data available on the .30 Herrett (this "friend" had to be the first kid on the block with almost everything), so since I had a bunch of Winchester 680 lying around that I was never gonna use, I figured that this would be a good start.
I started my loads at 15 grains, being conservative, and worked up to 20 grains in 1 grain increments. Every load sucked! Maybe it was the bullet my friend insisted I use...the 150 grain Sierra round nose!
There were no pressure problems at 20 grains so I went up to 24 grains, at 0.5 grain increments (wasn't gonna push my luck). When I got up to 23 grains there were some signs of pressure, and the cases fell in love with the chamber of that Thompson and refused to leave it!
I then started the process all over again, at 20 grains and stopped at 22 grains, working in 0.5 grain increments. It made no difference what the powder load was in that range! Velocities were all over the place, and there really wasn't anything I could call a "group" at 100 yards. The best was 5 shots that measured around 5-inches with 22 grains. So that is where I left it!
My friend was most impressed...according to him that was "good enough" for deer. (geesh!)
I offered him some advice as to what to do with that firearm and that caliber, and if he took it, I hope that the proctologist had as much fun with it as I did!!!
For loading data,
http://stevespages.com/page8c.htm