I want to give a shout out to the OP (DMcBB) for inspiring me to try the 9/40 conversion.

I knew the 5906TSW and 4006TSW barrels would interchange but I never shot it that way.

Anyway, Sunday was a colorful fall day up on the ridge, so I decided to shoot my as yet unshot (by me) CHP 4006TSW.
(The CHP shot it plenty! )

I remembered I still had an unmodified 5906TSW barrel and tried it in the CHP 4006TSW.
It fit and dropped out with no hood stoning.

So I loaded the CHP mag with Federal 180 gr FMJ and loaded a 5906 mag with Federal 115 gr FMJ and went out to the back yard.

Shot the mag of 40 with no problems, then switched the barrel and magazine to the 9mm components and shot the mag of 9mm no problem.

They both shot to the same elevation just left of POA at 11 yards.

I have plenty of 9mm pistols and have absolutely no need for this conversion (or for that matter, practically all of the other conversions I have done) but the Dr. Frankengun within me just could not resist and doggone it, IT WAS FUN!!!

John