Just buy a pistol with the barrel configuration that you want.
The receiver tube is the serialized part. So, you are, essentially, buying another firearm when you buy a Paclite upper.
I don't think it is worthwhile to modify the Mk II.
Keep the Mk II for fun.
Use the new beater for whatever requires threading.
__________________
Don't even try it. It's even worse than the internet would lead you to believe.
|