Besides th 7mm-08, H&R also offers a 7mm bore in the 280 Remington and has offered the 7x57 and 7x64 Brenneke in the past, none of them are small enough to convert to 7-30.
The 6.5x55 I'm having done is on a Shilen match barrel, my gunsmith, Wayne York of
Oregunsmithing is going to weld an underlug to the barrel from a donor barrel I sent him.
Another option for converion would be a barrel stubbing where the chamber and underlug of a donor barrel is threaded to accept a threaded barrel.
Any way you look at it, to get a caliber not offered by H&R is going cost $250 minimum for the conversion work, Wayne charges about $300 for a rebore, plus any ejector/chambering work.
As far as rimmed vs rimless, it's a moot point with current production as all are extractors which don't have the stuck case issues the ejector did, although with a properly cleaned and functioning ejector, they aren't a problem either. I've got a bunch of them, the only time I have a problem is if the load is too hot or the chamber/brass is ontaminated with fouling or oil/solvent. Even my 280 Improved with too hot of loads doesn't stick brass.
laOtto222, not a problem, that's a common mispelling, and I've been called much worse!!!
Tim