It seems like forever but I got tired of waiting for some welding work on the .458S's forend to be finished so I went ahead a tried out the MI Blast Can on the .338 Spectre.  It has the 5.56 BC on it since the .338 is treaded 1/2 x 28 but easily clears a .338 bullet as mentioned previously.
Previously the .338 had a KX3 for a .308 on it (with thread adapter) and I am happy to report the MI BC does as good a job of directing the blast away from the shooter as does the three times more expensive, and fatter, KX3.  Plus, no need to disassemble it for cleaning since the MI BC is one piece.  It's a winner!

Well fudge, my previous plans went bust on the .458 with the Blast Can so I had to remove the welded on Blast Can and change forends.  While I ended up wasting a 12" DD forend, I prefer the MI forend anyway so other than the wallet hit I am happy with it.
For those who gives a rat's ass, here is what a 13.5 inch barrel with the MI Blast Can permanently attached to make the finished barrel length 16.250 inches.
The forend now is the excellent MI Gen 3 Keymod KL light weight, 12.625 inch.

I snagged one of these for my 7.5" SBR. Good quality.

I like it more than previous flash cans I have owned. Nicer looking and a bit more thought out. Price is competitive.
Never been disappointed with an MI product and this is no exception.

I'm guessing but quite certain that one threaded for the standard thread for 450 Bushmaster would be a big seller. There are lots of guys setting these up for hunting rifles where ear protection is not always used. I know I would buy a few.

Light, inexpensive - just about what I need.  Does anyone know if, this far down the road from the initial post, the cans are made for 300 Blackout yet?

60 day rule