Sac Peterson. Got them ordered for these new 90's too!

Let’s see what I can add.  The early USPFA frames were Uberti.  The hammers featured the floating conical firing pin.  No recoil plate, just a hole in the frame to accomodate the firing pin.  USFA would later start to drill the frame and add a recoil plate.

 For the most part, USFA (US) hammers featured a cone shaped fixed firing pin.  The recoil plate had a slightly larger hole to accomodate the pin.  38 special was the normal caliber on USFA (US), not 357.  HOWEVER, as Pangea noted he has a US made revolver in 357 and that’s true.  If it was built correctly it should have a conical shaped fixed firing pin and with a recoil plate with a slightly smaller hole because the conical firing pin is smaller in diameter.  The Lend Lease guns were were done in 45 ACP or 357 Mag.

Not to muddy the water, but there are a few USFA (US) single actions out there in 32-20 with and extra 32 H&R, and 32 mag cylinder.  These also have the conical firing pin and smaller holed recoil plate.

Most of the above is but there’s more exceptions that escape me at the moment.

The cylinder and barrel look Colt.  It does not look like a Forehand & Wadsworth.

What I thought. A Winchester. https://revivaler.com/winchester-1883-prototype-revolver/

When Colt announced the Colt Burgess lever action rifle, Winchester in return announced that they were going to start making that revolver.

I beg to differ, but I have one in 357 magnum in the 28XXX serial number range. Also has a 9mm cylinder with it, 5 1/2 inch barrel.

More than likely a special run. As the common guns they were only offered in .38 Special after they became USFA.
I wish Gary G. would come on this thread and enlighten us. 

I sent a PM to Gary G. maybe he can give us some answers.

Got my 2nd 1890 today, matching the one I got last month!