Colt Ace Magazines in a Marvel

So I came across some new old stock of colt ace magazines, not sure what version or how old they are, Will they work in the newer Marvel unit 1 Steele conversions? They insert fine, and they lock back, just haven't shot with one yet. Not sure if I need to do any modifications to make them function 100% reliable. 

I just purchased a few of the new old stock mags. I had to adjust the lips to Marvels specs, but other than that they work great in my steel marvel. They do not lock back for me, but I am okay with that.

Jwhelan939 wrote:I just purchased a few of the new old stock mags. I had to adjust the lips to Marvels specs, but other than that they work great in my steel marvel. They do not lock back for me, but I am okay with that.

How do I find the correct specs on the lips and do you need a special tool? also, I loosened the slide and pushed the slide stop pin out a hair so it wasn't too tight against the frame, enough to slide a piece of paper between frame and slide stop, worked and locks back fine now, at first it didn't. Maybe give that a try.

https://guntalk-online.com/images/Marvel_Functioning.pdf This pdf gives the specs. I just use a big flathead screwdriver and then a ceramic stone to polish the lips.

Colt mags are all I use.   Used an aluminum marvel (non lock back) for years and about two years ago switched to a steel lock back model and they work fine.  I haven’t used the lock back followers yet though so my unit doesn’t lock back.  Ironically one of the features I wanted most was the lock back but I have yet to use it and don’t really miss it. I didn’t realize the mags should be adjusted to work with Marvels but my original conversion came with them so they were likely adjusted from the factory. 

John