twist rate? and some others
 

I have been thinking about building a Whisper for some time and have read a few things over the last year but I have a question or two and any suggestions would be great. I have a Savage action that needs a barrel and that's why this project has come to the front agian, I have put several barrels on so I'm looking for a pre-threaded fully chambered barrel for this project. I have found one from SSS but it only comes in a 10 twist, I don't want to go thru the pain (is it a real pain?) of getting a "can" but I do want to play around with subsonic loads for pest control, plus I will be shooting supersonic as well. So how heavy of a bullet can I shoot with a 10 twist? Could it stabilize a 220 or 240 SMK for at least 50-75 yards? Any other barrel makes with a twist rate (8 twist?)for the 220's or 240's that I can get a barrel for about $300 ready to thread on? If I do want a can at a later date can I have the barrel threaded with a cap/thread protector with out any special permits? Any thing else I should consider?
Thanks-Ron

Getting a can is not really a pain. You fill out the paperwork, have the local sheriff sign it and then send it to ATF with $200. Two to three months later you can pick up your can.
With a 1 in 10 twist your best choice for a 220 bullet would be the Hornady 220 grain interlock. It is a round nose which makes it shorter that other 220 gr bullets and it will stabilize in a 1 in 10. As far as other 220 gr bullets they will not stabilize well enough to give you the accuracy needed for pest control. Pac-Nor can make you a pre-threaded barrel in any twist you want for under $300.

Douglas makes a 1:8 twist blank and if I was spending the money with any plans on a future can I would not go with anythong other then the 1:8 twist... Your silencer and hastle to get it is worth the extra effort to find a 1:8 twist blank in my oppinion...