What are the differences between the FMAP and DWM 1909 Argentine actions; mechanically, metallurgically, and/or in terms of quality?

I inspected 4 of these actions recently and they were extremely smooth and well made. Don’t know about the metallurgy but they appeared to have fired a lot of rounds with no setback whatsoever, only thing was the firing pin holes had worn quite a lot to one side. Couldn’t figure out why. I was thinking of re- bushing them but decided to let them go. Still, they were butter smooth and tight and definitely comparable to the German 09’s although the markings are not as sexy.

I always thought they were equal to the DWM ones; good for standard cartridges as is, but not for magnums. Firing pin hole erosion is due to bad ammo leaking primers. Yes, the markings are not as cool.

I've built two rifles using them, a 7x57 and a 257 Roberts. Other than the markings, no difference.

Coincidentally, my favorite 7x57 is built on an FMAP receiver.

I've probably built an even number of rifles on the DWM and FMAP actions. On the whole, I've seen more DWM's with setback than FMAPs. I think the DWM's are better finished.

Thank you, guys.

I recall a comment by Tom Burgess that the metallurgy of the FMAP’s was a little different than pre-war German receivers, and they took a little longer in to recarburize. Don’t see this as a bad thing.