I'm afraid we may have stolen the word custom from the automobile industry. A vehicle rolls off the line, just like the last one, and the next one, but the owner takes it to a person who adds custom features, from the word customer, to make it personalized. That's it. Nothing complicated, and it's simply a personalization thing, and mostly prestige. And it certainly doesn't matter...unless someone is purporting a custom made rifle, that isn't. He, he, he...