I really don't have any time for prototyping these days, but I grabbed this pistol a month ago for this reason, so just needed to get it done.
100% 17-4 H900, 1.25 x 6.5", 8.7 ounces with booster assembly. Haven't metered it yet, just put a few through it out back, but my ears liken it to a suppressed .22 pistol running hyper velocity ammo. Comfortable to naked ears, quieter than your typical 9mm 147 gr. sub loads suppressed, but a bit snappier than 158 gr stuff like Fiocchi. Gun cycled well as long as I maintained a firm grip. Honestly, my biggest concern with this gun was case head ruptures, but the cases show no evidence of early breech opening.
Welding was tricky. The blast chamber is .030" wall, but the rest of the baffle skirts are just .020" wall.
The booster is a little unique in this critter, and it's one area that I plan to refine. But I did this prototype build with no drawings, and it came out quite well considering.
Time will tell if the pistol itself can handle the extra strain of running suppressed. I'll do my best to keep this updated!