I recently purchased a Browning hi-power Barrel from Brownells. There really is no shoulder on the threads. I have a coastal 9 mm ultima can. Any ideas on how I can make this work? I contacted Coastal but they never got back to me.is it ok to just tighten it up until the threads bottom out? I tried it this way and poi shift was terrible. No baffle strikes but off the target completely.

Under header of '...for what it is worth..":

Putting a threaded barrel onto a pre-War
FN Hi Power, it incorporated a stainless threaded steel
machined annular disk that served as a shoulder.
Tight and aligned. Then can kept its perpendicular
orientation.

Shall hunt for note on actual measurements if desired.

If you have a lathe so much the better as you can thread
a rod, part it, and voila.

Could you post what barrel you posses and dimensions.

Best.