brent's bore gophers are working great in the .40-65 sharps.
FWIW, the components i use are ...
dewey nylon rifle brush ~ .416" ~ 8-32 thread ~ $1.59 each at BACO
mcmaster-carr ...
neoprene washer ~ No. 12 ~ 0.195" 0.438" ~ 0.078"-0.108" ~ Durometer 55A ~ part #90133A021 ~ $10.93 (100 count)
brass narrow hex nut ~ 8-32 1/4" 3/32" ~ part #95130A130 ~ $5.13 (100 count)
VFG weapons care felts ~ .40/10.3mm ~ $50 (500 count)
one felt twists on the front end of the brush, up to but not past the brush's bristles. to get a felt onto the back end of the brush, i open up the felt's hole with bbq bamboo skewers - 1/8" and then 3/16" - grease the skewers with black powder lube. use the same lube on the brush's screw threads and shank. push and twist the felt onto the brush, past the threads and onto the shank. slip on a washer, screw on a brass nut, then another nut. about 3/16" or so of the threads will show - use side cutters to lop off, file off the burr smooth. i've had no need to loctite the nuts. these are small brass nuts that are 3/32" thin and 1/4" wide. using larger nuts won't allow the washer to bend and makes pushing through the bore a chore - been there, done that.
back from a day at the range ...
https://i.imgur.com/BtDSEUb.jpg
