THIS IS AN OLD DESIEN ITS ONLY LISTED TO SHOW WHAT NEEDS TO BE DONE TO THE DENIX. REFERENCE THE PICTURES ONLY TO GET THE BULL BARREL TO FIT..
you will need to modify your denix a bit for this to slide on correctly. But I’ve designed it to be the most basic of mods. And the inside of the bull barrel is male/female to the denix.
If if you want a bull barrel that requires less work for it to fit use this one. Link below. It just slides right into place (just not as far up)..
https://www.shapeways.com/product/EGE7UQ525/bull-barrel?optionId=61747363