Cylinder swap -- 940 9mm cyl into 340 M&P

[dmobrien2001]

I have a spare 940 9mm cylinder that I would like to swap into a 340 M&P (not yet owned) or some other 340 model to effectively create a airweight/scandium 9mm snub. Is this plug n play? Or need minor fitting/timing?

I've read of others using a 642 for the swap in, but the pressures of the 9mm round are in the 357 mag range.

Thoughts?

TIA!

 

[HEADKNOCKER]

The cylinder for the 340M&P will be the magnum lenth J frame cylinder were the 9mm 940 will be the 38spl lenth cylinder..
I have heard that S&W made a 940-2 with the magnum lenth 9mm cylinder but have never seen one..
The 940 & 940-1 cylinders are of the short variety..
That's why I used a 642 No Dash for my convertion to 9mm..
Good Luck!!
Gary/Hk

 

[dmobrien2001]

The cylinder for the 340M&P will be the magnum lenth J frame cylinder were the 9mm 940 will be the 38spl lenth cylinder..
I have heard that S&W made a 940-2 with the magnum lenth 9mm cylinder but have never seen one..
The 940 & 940-1 cylinders are of the short variety..
That's why I used a 642 No Dash for my convertion to 9mm..
Good Luck!!
Gary/Hk

Ok, it is what it is. I'm disappointed. I'll stop chasing this rainbow. Thanks!

 

[WC145]

Ok, it is what it is. I'm disappointed. I'll stop chasing this rainbow. Thanks!

You could always have your cylinder rechambered. That's what I did with my 360J, it'll shoot 9mm, .38 Super, 9x21, 356TSW, 9x23, and a couple of others.

 

[dmobrien2001]

You could always have your cylinder rechambered. That's what I did with my 360J, it'll shoot 9mm, .38 Super, 9x21, 356TSW, 9x23, and a couple of others.

Will it handle the full moon clips?

 

[WC145]

Will it handle the full moon clips?

Yes, the moonclip conversion is part of the job since there's no ridge for the cases to headspace on. I had mine done by Mark Hartshorne/Pinnacle High Performance, he charges $225 for a J-frame. You use the same moonclips as a 940, I've bought mine direct from S&W.

 

[dmobrien2001]

Yes, the moonclip conversion is part of the job since there's no ridge for the cases to headspace on. I had mine done by Mark Hartshorne/Pinnacle High Performance, he charges $225 for a J-frame. You use the same moonclips as a 940, I've bought mine direct from S&W.

Very nice. NOW I have a new project! Thanks!

ETA: I contacted Mark via his web page and will report back.

 

[WC145]

I suggest you call Mark, he's terrible at returning email. When you talk to him, tell him Scott in Maine sent you!