The actions mentioned in the RUM line would need the least amount of work but the bolt face will need a little work because the RUM cartridge has a rebated rim it is the same as all the belted mags so a little work would be needed. Standard mag bolt face is .535 404 Jeffery is .545. The 404 will probably slide into the .535 bolt face because they build in a little play but to keep the same play in 404 you need to make it a bit bigger. Shawn I’m in the last stages of a 404 Jeffery on a standard 98. Should have it shooting by mid February and doing all the work myself except PAC NOR barrel.