Need an old-timer's help here...

I posted a long time ago about my first gun, an Iver Johnson Sealed Target 8, Second Model. She's a super-fun plinker and pretty darn tight for her age.

My question is, given its fairly robust construction, what types of .22 rounds can I load into it? The cylinder seems long enough to accomodate WMR, but this pistol predates the inception of that round, so I have no data to go off of.

Does it stand to reason that it would be better to have the tip of the round closer to the barrel, rather than travelling unsupported down 1/3 of the cylinder? Or am I just asking too much of an old wheelgun?