Bill
I regularly make custom long range rods for my customers with longer barrels even those in the 50"+ length. Just get a 6' stainless rod from McMaster Car in 5/16 or 3/8, cut to the needed length ,thread one end ,turn wooden handle and pin the handle to the rod.They can be used as range rods or cleaning rods depending on the jag installed.
Mitch Yates