I can't believe there is actually a debate on whether or not the bp express is a custom muzzleloader or not. Marketing or not, it is being touted as the worlds best custom muzzleloader. Why would you call it a custom muzzleloader repeatedly (look at the website, its all over) if it is not a custom muzzleloader? Is it because he wants to look like a liar? I think not. It's probably because He believes it's a custom muzzleloader, go figure.
We can use word play on the words "custom" and "production" but i think it is common sense that the bp express is not a production muzzleloader in the usual sense of the word. It is a production muzzleloader in the sense that is was produced...thats as far as it goes. Just because they are all built the same doesnt mean squat. The gun is made of a hodge podge of parts and is made per order. Using another gun factory's action, an aftermarket barrel, and your own breechplug system, and then throwing it all together on an order by order basis certainly is a custom.