I built some various-length cleaning rods from wood dowels and 9mm brass, threaded to 8-32 to receive standard cleaning jags and brushes. To fit 5/16-27 shotgun accessories, I used an 8-32 to 5/16-27 adapter.
Then I bought a 5/16-27 tap to fit shotgun-sized accessories directly.
You can drill a pilot hole in a .45 ACP, or a 9mm shell, with a Letter I drill.
About 3/16" of brass is revealed. This can be tapped to 5/16-27 threads easily.
The .45 ACP shell can be epoxied to a 7/16" dowel with almost a perfect fit.
Then I tried tapping a 9mm shell with 5/16-27. It works also. Lots of brass to thread. This epoxies to a nominal 3/8" dowel (actually 11/32" or a metric equivalent, or sand the 3/8" dowel to fit the 9mm shell).
These cleaning rods can be made to any length --
- 1/4" dowel rods with .25ACP brass tips threaded to 8-32
- palm-sized short with 9mm tips, for cleaning larger bore revolver cylinders and barrels like .45 Colt or .45ACP;
- medium, with .45ACP tips for 20" barrel 12-ga shotguns;
- or long, for 30" .45 Colt 1873 barrels or longer 12-ga shotguns.
Shorter shotgun cleaning rods are difficult to come by. Most are 36" long -- way too long for a 20" double barrel Cowboy Action shotgun.
Left: .45ACP with 5/16-27 threads
Right: 9mm with 5/16-27 threads
Left: 9mm shell threaded to 8-32, epoxied to 3/8" (11/32) dowel
Right: .32ACP shell threaded to 8-32, epoxied to 11/32" dowel
Finally, you can thread to 8-36 to handle milspec accessories like a AR-15 chamber brush.