There is a FS .45 slide, barrel, and guide rod on an auction website for a very good price. Will it fit on my FS 1.0 & 2.0 MP .40 frame?

I'm not sure 45 is interchangeable with 9/40. And I don't think the 45 mags would fit in the 40 frame. I've never seen a gun where 45acp mags fit into a 40/9 frame. This is one of the reasons why in the Sig 250/320 you can change from 40 to 9 but 45 you can only make full size down to sub compact

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One of the knocks on 45ACP weapons was that the grip size (front/back) was too large for those with smaller hands to grasp well. When the 40S&W was designed, it had an overall cartridge length that would fit in 9mm-size grips. So it's a virtual certainty that a gun designed for 9mm/40S&W will NOT have a grip frame long enough front to back to take the 45ACP round.

Simple answer is NO

The simple answer and the 100% true and factual answer!!

9mm and .40 slides can be interchanged and the long slides and 4.25" slides go on the same sized frames but .45 is .45 and thats all she wrote!

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