A homegrown gun maker who is not getting federal subsidies is not directly comparable.
In Raich and Stewart, Congress has decided to completely extinguish the interstate market in cannabis and in unregistered machine guns, respectively.
A homegrown gun maker who is not making NFA weapons is not directly comparable.
Wickard vs Filburn
That case is not going away, and it makes two important points:
1. The power to regulate interstate commerce extends to the regulation of those things that affect interstate commerce, even if they occur entirely within one state. (The Substantial Effects Test.)
2. The fact that one guy with a few acres of wheat really doesn't affect interstate commerce does not matter if there are lots of other people who are similarly situated, and if their combined actions, taken as a whole, could affect interstate commerce. (The Aggregation Principle.)
So do you agree that under Wickard
that the federal govt can regulate the manufacture and sale of firearms even if the firearms are manufactured and sold entirely within one state?