Does anyone know if you can add a 5/8x24 thread 4" extension to a 16" barrel to keep the pressure so the rifle can shoot like a 20"? I have heard you loose X amount of pressure per inch of barrel and was looking to see if you could buy an extension instead of buying a new barrel. thks.
Can’t be done. Sorry. The internal dimensions are too sensitive.
The velocity difference between a 16" and 20" barrel is only iirc 150fps.
Why don’t you give it a shot then report back to us with your results.
A barrel extension can be done, but it’s not very practical. By the time the costs for labor and material were added up, it’d be cheaper to simply buy and install a replacement barrel.
Before getting too wrapped up in the project either way, what is you you want the rifle to do that cannot be done with a 16" barrel?
Sell 16" barrel then buy 20" barrel
Nyet.