The 7mm TC/u is a necked up .223 case and is a very good cartridge, and is easy to load for.
140 and 160 grain Sierra Spirepoint boolits are what I loaded for IHMSA, 'back in the day'.
The 7mm International Rimmed was 'supposedly' created by Elgin Gates, and is very much like the 7-30 Waters. (They MAY be the same cartridge. ????) :dunno:
I had the 7mm Int'l R for a while. With 140 grain boolits, it was a screamer!!!!! It's nothing more than a .30-30 case necked down to 7mm, or a .375 Winchester case necked down to 7mm.
The .30 Herrett is a screaming little cartridge, too.
Again, the .30-30 shortened, will push a 110 or 130 grain boolit very quickly, and can take most big game in the U.S.
I had a .44 magnum barrel, that was NOT accurate with any handload that I tried, but, was very accurate with Federal 240 gr JHP and 180 gr JHP!!!!!!
(I even broke my thumb, from the recoil and the hammer extension, with that .44!)