What are the pressures on a "normal" ML load anyway? I'm shooting 80 grains of BH209 and a 348 PB, I'd guess the pressures were fairly low. The threads are deeper than other designs I've seen, and they run for about an inch and a half, look pretty stout to me.
Haven't singed any eyebrows yet, anyway.
Since shotguns shoot sabot slugs at similar speeds as a ML you could assume that working pressures might be in the same ballpark.
Obviously this isn't 100% correct but it's ballparlkish close.
