Starrett has never made parallel punches with a cup tip. WTF?. IF they made them, I would own them. The cup tipped ones are tapered nail setting punches to be re-purposed as "starter" punches to get the domed head pin moving for a few millimeters.
Now however, most of Starrett mfg. has been...
You can fabricate small cup tipped punches from Brownells replaceable pin punches, which are essentially hard ejector pins. A Dremel ball tipped bit to the end of the punch. Done.
IF you cannot easily source them, you can modify a common punch to complete the task. Either a brass or steel parallel pin punch host with Dremel ball to create the "cup tip" OR use nail finishing punches that have a cup tipped surface.
FYI- Most of the S&W & Beretta punch shafts are so small...
I have the M&P 22 Compact with 6500 rounds; purchased 2015; no issues whatsoever.
I have two M&P22 full size;
MP22 #1 Purchased 2015
Firing Pin Spring fractured @ 10,905 rounds
fabricated a brass guide rod for spring to prevent its buckling which was the cause of fatigue fracture
Ejector...
Last year I acquired this new-old-stock no dash M57.
Historical letter indicates a 1981 shipping date to a well-known sporting goods store in Jackson Mississipi. Completely disassembled and cleaned.
"But I would much rather have a 590A1 than a Shockwave."
No worries for me.
I am quite familiar with the Rules. They are registered with BATFE as SBS's; $200 / each.
No Tax $ now!
The 14" 590A1.
Have it your way.
Just an amateur but this is how I do it.
Pretty easy to do. It's a simple hand-driven cylinder chamber chamfering tool with a caliber specific pilot. After the primary chamfering, polishing with a burnishing bob and finalized with a Spyderco ceramic cylindrical polishing tool. Here's a M65-3...
There is supposed to be trigger stop rod in the M57.
Maybe the rebound trigger spring is not the correct one, i.e. too long? supposed to only have 17 coils; maybe it is solid stacking.
Maybe cut 1-1/2 coils off the existing rebound spring.
Measuring the dovetail width is easy. Just need two identical gage pins and accurate calipers or inside micrometer.
This is how I do it and the science behind it.