anyone have any stratageys if you go with qd hub mounts to prevent putting a can on the wrong caliber
I apologize in advance for not having a very helpful answer here. I've thought about implementing some sort of system like this - either having one system for smaller bore cans and one for larger cans, or having a QD system for .30 caliber cans and direct threading smaller cans. Ultimately I've just settled on religiously double-checking that every can matches the caliber of the gun that I'm putting it on.
One issue that I've run into is that when you don't have very many cans, you might want to put a .30 caliber can on a 5.56 rifle, which isn't optimal but is way better than not suppressing it at all. If those are using different mounting systems, then this becomes harder to do. If you shoot with friends, it's also nice to be able to lend them a can while you're at the range together, and that's much easier if they are using direct thread or a standardized QD system. I'll often toss my friends spare .30 caliber cans at the range and I like not having to worry about what mounting system they use and whether it matches what I use for a specific caliber.
Another issue is that as I've gotten more cans, I've had less of a clear distinction between large and small bore cans. I now have cans in 5.56mm, 6mm, 6.5mm, .30 caliber, and various pistol calibers, and I don't know how to implement a foolproof system of breaking those up that wouldn't leave me juggling too many mount types or at risk of putting the wrong can on a gun.
Ultimately I think that if money were no object, the best solution would be to have a dedicated suppressor for each gun that you own, but that's not going to be practical for a lot of people. If anyone has a foolproof system for matching suppressor mounts to guns, I'd love to hear it. As best as I can tell, it's a lot less effort to just read the number on the can and make sure that it's equal to or greater than the number on the gun.