Amigo, screw on a .375 barrel 24" long with either 1x12 or 1x14 twist and have it chambered for the 375 nitro express 2.5 cartridge
with the rim. I think you can rework the hornady 405 winchester brass by cutting it down to 2 1/2". Can shoot a 270 grain bullet at 1900feet per second. Will definitely be different, try and locate one of the winchester rear barrel mounted sights like they installed on the .375 and 458 caliber rifles. Course if you are plinking you could use the speer 235 grain bullet or since its a .375 rifle cast your own bullets with weights up to 300grains and have fun. I have/had a ruger #3 in 45/70 that I had converted to a cast bullet rifle in 30-30 wcf. Way to heavy for hunting but its fun at the range. Ix14 twist should be able to handle the 300 grain bullest and should be a good stopper. Fairly low pressure about 31,000 or in that area. Brass should last. Frank