Thanks for the replies. I finished the rifle yesterday and fired it today. (gotta love retirement!)
I took one of my Axis skinny bbl 223s and put on a new 22" Skinner bbl in 300 Blackout. Varmint profile. It measured .970" where it exited the front of the stock. I didn't think there was any way this would fit and not look like a kluge. Using a die grinder, a carbide burr and a hook type deburring tool, it took many trial fits. I finished it off with a 1" piece of bar stock with 150 grit sandpaper.
Not only does it look 'factory', it is free floated from the recoil lug forward. Next time I take it apart, I'll reinforce the forend.
The 300 was so easy to headspace, it seemed TOO easy. Putting the same scope back on the rifle and firing 220 gr sub sonic loads, it took just a few vertical clicks to put it back on center.
The Skinner bbl was very, very nice, and had a threaded muzzle and thread protector.

ron