Turn around time is now pretty long.
Just wait.
You will like it when you finally get it!
I've had a M1S 300-221 upper for a couple of years & am VERY pleased w/it.
You need to load a short COAL as it is not exactly the same throat as 300 Whisper.
It will shoot sub 1" groups if you do what you should.
http://www.quarterbore.net/forums/ph....php?photo=452