Nate,
I've had two .22 HP's, both the original Savage 99 take-down model. They both shot well with the right .224 bullet, but one of the other "problems" that can plague .22 HP's of that era is the rifling twist. Savage used sine-bar machines, which could result in somewhat variable twists. Have owned old 99's that had twists an inch (or a little more) different from the "listed twist."
This can cause interesting problems with bullet stability. One old .250-3000 actually had a 1-15 twist, rather than the then-standard 1-14, and would NOT shoot any lead-cored 100-grain bullet accurately, even here in Montana at 4000+ feet elevation in summer. Even the 100-grain Speer Hot-Cor grouped into 3-5".=, when it had grouped very well with other slow-twist .250's, Finally had to go to the 87-grain Hot-Cor (which was apparently originally designed for the 1-14 twist) to get decent groups.
The problem can be compounded with .22 HP's because the most commonly available bullet supposedly made for the cartridge was the 70-grain .227 Hornady Interlock Spire Point. However, from what I understand this was actually made for the Euro-equivalent cartridge, the 5.6x52R, used over there in break-action rifles for shooting smaller big game. They usually have about a 1-10 twist, not the nominal 1-12 of the .22 HP Savage 99's.
Consequently the Hornady bullet doesn't always shoot very well, because its length is marginal for a 1-12 twist. In fact neither one of the .22 HP 99's I handloaded for would group it worth a darn either--though the first one (purchased long before the 60-grain Partition appeared) shot pretty well with the 60-grain .224 Hornady spitzer.
