M&P Gen 1 experts needed, to answer barrel compatability ?

[arakboss]

I am thinking about picking up a Gen 1 M&P 40C pistol. Will Gen 1 M&P full size barrels fit and function in the Gen 1 compact?

Will M&P 2.0 Compact barrels fit and function in Gen 1 compact?


Supposedly it worked for this guy's pistol but others have said the full size barrel won't work in the compact.





Source: https://www.mp-pistol.com/threads/m-p-full-size-barrel-in-a-compact.36232/#lg=thread-36232&slide=11

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[arakboss]

Looks like I will be answering the questions myself. I pulled the trigger on buying the 40C in combination with a rifle today. If I had waited and bought them separate, I don't think I would have gotten as good of a deal. And it was the only used 40C they had left in stock. I should be able to pick it up tomorrow but will have to dig around in my piles to find the Gen 1 full size barrels and the 2.0 barrels both full size and compact. Might not happen until Sunday.

 

[FATAL125]

I am thinking about picking up a Gen 1 M&P 40C pistol. Will Gen 1 M&P full size barrels fit and function in the Gen 1 compact?

Will M&P 2.0 Compact barrels fit and function in Gen 1 compact?


Supposedly it worked for this guy's pistol but others have said the full size barrel won't work in the compact.


View attachment 1811662


Source: https://www.mp-pistol.com/threads/m-p-full-size-barrel-in-a-compact.36232/#lg=thread-36232&slide=11

Looks like I will be answering the questions myself. I pulled the trigger on buying the 40C in combination with a rifle today. If I had waited and bought them separate, I don't think I would have gotten as good of a deal. And it was the only used 40C they had left in stock. I should be able to pick it up tomorrow but will have to dig around in my piles to find the Gen 1 full size barrels and the 2.0 barrels both full size and compact. Might not happen until Sunday.

Sorry I'm not gonna be any help with the original question...

However, I am curious why you're wanting to run a full size barrel in the compact? Are you looking forna slight velocity increase? Is the full size barrel threaded?

 

[arakboss]

Sorry I'm not gonna be any help with the original question...

However, I am curious why you're wanting to run a full size barrel in the compact? Are you looking forna slight velocity increase? Is the full size barrel threaded?

I already own factory 9mm and 357 sig full size Gen 1 barrels and a storm lake 40 to 9mm full size conversion barrel. I didn't want to have to order more barrels for a gun that will be shot very infrequently.

 

[arakboss]

Preliminary suggest that M&P 2.0 barrels will not work in Gen 1 compact slide. They appear to share a similar lug pattern but with some differences around the barrel circumference near the chamber. I installed the 2.0 barrels in the Gen 1 slide and the slide would not slide back far enough for the slide lock to engage in the slide. It was close but need another 1/8th inch or so of travel for the slide lock to engage. I think I will give up on the idea of using the 2.0 barrels and search for Gen 1 compact barrels in 9mm and 357sig. Maybe one day in retirement I will attempt to modify the barrel or slide to make the 2.0 barrels fit but I don't have time or motivation to deal with it now.

 

[arakboss]

The 2.0 barrels are on the left and middle, Gen 1 barrel is on the right. I believe that 2.0 barrels could be ground down to share a profile more similar to the Gen 1 barrel but I don't know if that would prevent them from functioning in the 2.0 slides? Probably better to buy some Gen 1 Compact barrels instead.

 

[arakboss]

Problem has been solved!

I found a factory 9mm Gen 1 full size barrel that I picked up from @JohnH many moons ago. It shares the same lug pattern and barrel shape as the M&P 40C barrel. I installed it and it fits great. It locks back fine and is fairly tight in the barrel hood area where it fits in the slide. Accuracy shouldn't be an issue.

I have a M&P Gen 1 full size 357 sig barrel around here somewhere and it should work as well.

 

[arakboss]