After re-working my Marlin 880 (other thread) I've been shooting quite a bit of 22 lr. The wife even enjoys it, but much more so shooting reactive steel than just paper targets. My experience is you don't need any fancy steel for standard velocity lead 22 lr, 1/4" thick plate works just fine.
I convinced her to get her own gun and a couple weeks ago we picked up a Savage Mark II Laminate Thumbhole Heavy Stainless and, for now, just moved the optics from my 22 to hers. This is a topic for another thread but the gun shoots!
Anyway, back on topic. I made a deal that I would build her a gong set. We had 2 other single gongs a friend made, but we wanted a "know your limits" set. FIY, that is a set of decreasing size where you start at the largest and work your way down, stopping any time to take your points or keep going and risk loosing them all with a miss.
The frame is 3 feet wide and 3 feet high. The 7 gongs start at 2.75" and go down to just under 0.5". It is built in three parts and easy to take apart to re-arrange, transport, etc (or in case I need to fix my welds, haha). It should be just about perfect for 50 yards.
I think this is going to be a fun one to shoot. I'll report back on how it works and holds up after we get a chance to try it out, provided that there is a break in the rain one of these days.