I looked into this quite a bit because I was thinking about buying a 5.7 pistol. The problem is doing a bolt gun in one doesn't make much sense. The reason is the case isn't really viable to reload. You have such little brass around the primer. Ammo for 5.7 is pretty spendy and take away that option for the cartridge being suited to reloading and its not as cool as it may sound, all to have something that duplicates a 22 hornet more or less..
I bought the S&W, plus all the goodies needed to load for it, including the Sheridan cutaway gauge, but found the process pretty tedious, unlike the Hornet which has been about as easy as it gets for me. Now that ammo is getting cheaper, in particular the stuff from AAC (PSA), it’s not worth my time and the stress over the chance of double-charging that fast powder in the tiny case. The ones I did reload worked perfectly, aside from one case neck left in the chamber from some once-fired brass I bought. The S&W has a locked breech, so the brass shouldn’t take as much abuse as it does in the blowback guns.
So far, that pistol hasn’t lived up to my hopes about accuracy, being pretty much “service grade”, and tends to toss the first one out of the mag a bit high. Now it’s relegated to being a hi-cap house, carry, and trail pistol. It is very reliable with factory ammo and easy to rack, with a great trigger for a Tupperware®️ pistol, and makes enough noise to scare off just about anything.
