Shot my Herter's .401 Power Mag today.

[TonyRumore]

I had a Power Mag back in 1992 (pre-internet) and was unaware that the bore size was .403 at the time.  After cartwheeling 10mm auto bullets into the target, I promptly sold it.
Fast forward 27 years, I picked up another one, and this time loaded it with Reed's .404" 210gr bullets and all is well.  I also slugged the bore and found it to be .4025".

19.5gr of 300-MP pushed the 210gr HP to 1355fps from the Power Mag's 6.5" barrel.  The cases drop free from the cylinder.

I could probably heat up the load a bit, but I hate to loosen the primer pockets on my limited supply of scarce Herter's .401 brass.

Tony

[The_Shadow]

Interesting info there Tony!  Having that big of a bore size I can see the inaccuracies you experienced with the 0.4000" bullets.
Those cases are treasured for sure...
Thanks for sharing the info! 

[Jim Bridger]

That is a very interesting post. I think the Power Mags were made by JP Saur & Sons? I knew the Herter's . Col. Herter set up Gen Patton's mobile reloading Unit that followed his fast moving Army. His son Jaquez "Jack" Herter Jr. was the young man in the catalogs. He owned and operated a Mental Health   Clinic  in Casper, Wyoming. Dr. Herter would be 80 years old. I talked to Col. Herter before his passing. Please excuse my post. But the Herter .401 revolver brought back many memories.