S&W has a kit for you Honcho!
I have one myself.
For around $300 (I paid $330) you just buy the M&P22 part.
Next, put your .40 M&P in the safe, and pull out the M&P22.
It takes .22 bullets, comes with a magazine, and feels much like the M&P40.
The best part is with this kit, you can have two people shooting at the same time!!
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