Has anyone rechabered the 416 rem to the 416 rum?
What kind of velosity was gained?

I have never rechambered but I have built a .416 RUM and they run about 150fps faster. Not worth the 15-20 additional grains of powder if you ask me.

I had one built like Idaho CTD, 300RUM 416, On a long Rigby length so I could seat bullets out. Made up brass out of 375 RUM cases. I got 2620 FPS with 400 grain A Frames and 2400 fps with 450 grain woodleighs. I used 416 Dakota (essentially the same cartridge) and H4831 SC powder. I used a BP-Tec brake/compensator and it came back fast, straight back, actually with a little downward muzzle flip. Very accurate. PacNor stainless barrel. the Olympic Ultra Mag action the smith used was an absolute disaster, so the barrel is now a Waffenfabrikhein getting a new action on it. I really like the cartridge, and think It's the ideal 416 case. It performed really well at 3.6" or at 3.74" Overall length. Cheap brass, and maybe the optimum case size for the 416. to many peoples way of thinking Where in the Yukon do you live? I grew up in Haines just south of your border. Wayne

Walex
I shoot a 416 Hoffman (416 rem Imp )
91g of w.w.760 gives me 2500 f.p.s. with 400 swifts. I to shoot the BP-Tec break & love it. It is the only break that I shoot with no ear plugs contary to what all the nay sayers on this fourm spout about the increase in noise level. When Richard Lemmer & I were charged by a cow buff we both shot at the same time he did not know I had fired also till I showed him my empty hull !!We were both shoting 416 rem & were about 6 feet from each other.We both hit her but not a vital hit from either of us but did manage to turn her Was the high light of my trip as Saeed guest. Again thank you Saeed

the 416rem to rum is a good wildcat...see fred zeglin at http://www.z-hat.com/ look under ultracats

one of the best things about the idea is getting a stainless action...virtualy non existant in rigby length

Well, AEBE, you'll get a little more speed or a little less pressure. If you're looking for a fast 416, there are bigger cases, but if you're one who thinks the Rem at 62k or whatever is too hot for you, you can do the same a little cooler, which might be worth your money. If you Did like Walex, and put it on a magnum action, you could definitely get closer to Wby performance, with four down. My M70 gets 4 404J cases down. You could rebarrel a 300RUM and not have to deal much with the feeding. Maybe find someone to lengthen you out another .15" in the back....