>>64223785
Shotguns work on low pressures and also have all the space in the world for a big fuckoff locking lug somewhere.
It's also not so much that it's impossible to make a Magnum topbreak, it's that older designs from 120+ years ago with older metallurgy and older casing styles won't be strong enough to tolerate it.

Now, arguably your frame and lockup would need to be more beefy than you'd really like it to be if you wanted a topbreak which could rock Buffalo Bore loads like it was a Ruger Redhawk, but it's not like it needs to either, normal loadings of .44 Magnum aren't exactly meek stuff.

>>64223771
You can always get a Wrangler or Rough Rider for an inexpensive .22 cowboy gun, they're damn fun.