Have just finished up my 375 RUM build the way the cartridge should have been originally introduced. As a lefty I am a bit limited but was able to find a LH M70 CRF in 300 Win and have my smith convert it. Ended up with a #6 Krieger barrel finished at 24” with Sunny Hill bottom metal and restocked in a nice piece of Turkish by Al Lind. Swaro 1.7-10 sitting in Talley QR adds a lot of versatility on optics and dummy rounds feed through it like it was designed for it. Gun is a bit heavier at 10.9lbs but extra weight offsets the recoil and makes it fairly comfortable. Had the rifle throated with 350gr Barnes TSX’s at about 3.580” in mind or even the 350 PP Woodleighs, but 300gr TSXs will work fine if my load development doesn’t work as planned. The main goal for the rifle is to mimic the classic 375 H&H 300gr 2500-2600fps “all around” combo ballistically, but with 50gr. more bullet weight putting it on par with the 416 Rigby. Kind of a “one rifle for all” concept. Has anybody done any development with the RUM/350gr. combo? Quickload is pointing to RL26/VVN560/MRP/7828 SSC for higher velocity (2550-2600) and H4350/H4831SC for lower end 2475-2500). I have N560 and H4350 on hand and will likely start there but wanted to see if anybody had notes to compare first.