Good for you!
my Dies and brass arrived yesterday so I will be forming some 221 into 300 whisper and trying my loads as well. Paperwork still hasn't come thru for Can so unsuppressed for now.
On another board someone suggested if you were getting blow back from the charging handle area the quick fix was JB Weld or Silicone in the last little bit of the channel (from hook area to end) in a wedge shape to force the gas into the buttstock tube.
And it was suggested to put on a good solid brass catcher if your getting too much gas out of the ejection port. they used some sticky insulation tape to keep gas from flowing back towards the shooter.
Threaded Mode