How good are 250 grain SMK's running at only 1000 fps? They were intended for 3 times that though. It's out there
I'm not trying to be critical because I think it is cool when people think way outside the box and want to try something different, but its a pretty darned expensive way to shoot rabbits. With a 1000 fps muzzle velocity, you'd have more than a meter of drop at 200 meters.
What the hell.... ...I have a 338-08 and people scoff at that as being a waste of time too, although I love it! build your 338-39 on a sturdy receiver and play for a while and then re-chamber in Lapua Magnum! Now that you've brought up the idea, you HAVE to try it!