What models of Busse/Swamp Rat/Scrap Yard knives do you need to own in order to have a complete collection? Obviously, this answer will vary. But in my view, you need to have AT LEAST four knives to consider your collection complete:
1) A chopper, 9"-10" (e.g., Dog Father/Battle Rat/Battle Mistress)
I have a bunch in this category - Battle Guard, Dog Father, and (while not technically in the family, more like a distant relative) a Ranger RD9.
2) A camp knife, 5"-7" (e.g., Scrapper 6/Camp Tramp)
I have a Camp Tramp. WOuld definitely buy an S-7 if Scrapyard releases one.
3) A fat-bellied skinner/slicer, 3"-4" (e.g., Howling Rat)
I have a howling Rat.
4) A thin-bellied skinner/slicer, 3"-4" (e.g., Street Scrapper 4/Bandicoot)
I have a Bandicoot and a Scrapper 4.
And possibly a fighter, 6"-7" (e.g., Pure Bred Fighter/Satin Jack/Mini-Mojo).
I don't think that's really necessary. Any of the above could be used for that purpose.
And at least ONE of those knives has to be manufactured by Busse Combat.
I'd love to get a "real" Busse someday, but the Swamp Rats and Scrap Yards are more in my price range.
