Update. Thanks to a gentle reminder PM from vapodog today. I of course have been busy being retired, and having a good life, so this project has been a little farther down the priority list than a few others, one of which is keeping an eye on wildfires a bit south of us. I've decided I have to get going on it soon though.
While up in the big town a week or so back I picked up a couple of jugs of suitable powders. And after vapodog's machined bullets arrived, I ordered some of the 67gr Hammer bullets too. Will compare them against the machined TTSX ones once I get going.
Picture shows vapo's machine work on the left, a couple of ones with tips intact, one without, a dummy round I quickly put together to check fit and function, and three of the Hammer version. On my little scale , vapo's averaged about 68-69 gr without tips, the Hammers right about their stated 67 grs.
Here's the dummy in a Model 62 magazine, the case mouth is right at the upper edge of the last relief groove on the TTSX without the tip. Only a mm or two space before I run out of room, so that might be all I can get as far as length and not using too much powder space (shouldn't be an issue with the small charges). You can also notice the larger hollow point in the Hammer version.
sorry for the crappy cell phone pics, but I did this just a little while ago after getting the evening dog walks in, and taking care of the evening "chores", such as they are for a retired guy.
Along with fitting in the Marlin mag, I've got to dig out the revolver tomorrow, after we get back from the 2+ hour drive (each way) and appointments tomorrow in the Big Town. I want to make sure the round as it sits now will fit in the revolver cylinder and not interfere with rotation etc.
Once this is all done, I'll work up a dummy .25-20 round to check things out too, although that might wait until I test a few .256WinMags out at the range.
vapo, thanks for making up the bullets and the reminder today. pointer, thanks for the reminder to check with Hammer. You other guys, thanks for your input too. If these don't work I'll be looking into some of the other suggestions.
I'm sure hoping one or the other of these work, as I'd like to see how they work on a jackrabbit or two, and hopefully a chicken stealing coyote.