Bass Reeves is placed in a town at a point one has unlocked most firearms and probably used them. His (old) quest line was (and apparently, still is) to introduce the use of firearms and the concept of weakspots. At this point in the story line, this is completely irrelevant. Please consider changing his quests, and general conversation, to something slightly more relevant, or move him to a much earlier point in the story line. Thank you for reading this and the great dev work.
I'm all for moving him earlier in the story. He should be the one to give you the plan for your 1st firearm. I already had the Refined Leveraction Rifle unlocked and in uise when I met Mr Reeves.