Commander Slide
Howdy Ma Deuce,
The COmmander slide will physically mate to a 5-inch frame, assuming compatible dimensions in the rails, and it will function...after a fashion.
Gettin it to run right usually takes a little re-engineering, though.
The GM frame rails are .90-.100 inch longer than the Commander's, and
the slide travel is also reduced by that amount. When you try to mate
the short top end to the GM frame, you lose about .150 inch of travel,
and that can bring on some problems.
You'll need an extended ejector, and you'll have to play with the length
a little to find the sweet spot that will eject the brass in the right direction
and still allow live-round ejection. You'll probably also have to open up
the front of the port to allow you to leave enough length on the ejector
to do both.
You can recover a little of the lost slide travel by reducing the thickness of the recoil spring guide rod head...but there's a limit of about .045 inch
reduction before the slide hits the frame rails instead of the head when it recoils. (Lathe required)
The other route is to send the frame to be altered...which is the right way,
but a little expensive unless you plan to turn the gun into a Commander,
AND...you figure that it's worth the cost. Unless you happen to have a
Commander top-end and a GM frame lyin' around not earnin' their keep,
it's probably cheaper and simpler to just buy a Commander.
To make it look right, you'll also have to shorten the dust cover to line
up with the contour of the Commander slide at the front...at which point,
the gun won't work with a 5-inch top-end any more because the recoil
spring will be exposed.
I've done the swap a few times when I've had a decent frame but no slide...and a decent Commander slide but no frame.
Hope this helps!
Tuner