As far as I know, KAK doesn’t make 450B barrels. Maybe it’s a custom order for that particular company, but I would figure they would go another route. As to KAK quality, it’s ok. I have a 7.62x39 barrel from them that has worked out pretty well, however I wouldn’t use them for much else than a beater barrel.
I had a chance to look at Moriarti arms, it appears to me they are using quite a few Bear Creek Arsenal barrels. It definitely looks that way for the 450B. Bear Creek is about the same as KAK in my opinion. The 450B is pretty forgiving, so the Bear Creek barrels seem to do pretty good. Just a heads up, you might have to play with a few things to get it to run 100%, the few that I have seen needed to.
Thanks for the input everyone. Another .450b noob question. Is there any advantage of the 18 inch vs. the 16 inch barrel? I know its only 2 inches but it would add a little weight and some length. This gun is going to be used mostly for brush hunting hogs and deer.
Comparing barrels that are the same, just different lengths, there is only about a 100-150fps or so difference between a 16" and a 20" using factory ammo. Looking at different brands, there can be as big a difference in velocity. For a brush gun, you could use a pistol length barrel, and still be effective.