12 March 2007, 18:33
Paul KNecking up 416 Rigby to .475
Is there enough shoulder left to head space off of? If it has been done, wich i'm sure it has,what is it called and do i need a special reamer?
Paul K
13 March 2007, 09:53
470 MbogoThere is a big difference between a 416 Rigby being just necked up and the 470 Mbogo. It has been done before by a couple of people. On the 460 Weatherby case it's called the 475 A&M. It is listed in Cartridges of The World with some really bizzare ballistics. I still haven't figured out why they keep publishing those ballistics.
Take good care,
Dave
14 March 2007, 06:10
.366torqueSorry Dave I forgot the Mbogo has a lot more case capacity.
14 March 2007, 07:50
RobgunbuilderYou can headspace off of .010 with no issues. I have built two .470 Mbogos. they are great!-Rob
14 March 2007, 08:10
Idaho Sharpshooterhow about a 475 on the 505 Gibbs case? I just happen to have a reamer...hmmmmmmmmmmmmm?
Rich
DRSS
Rich,
To illustrate your point, some of my dummies:
Above are a fireformed 470 Mbogo and a .475/.505 Gibbs mockup aka ".475 Kifaru."
The Brothers Gibbs: .408, .475, .505, .510
15 March 2007, 14:47
gumboot458RIP ;; is that what the 408 CheTac is ,, a 505 necked to 408 ??? Quite a useful looking round...
gumboot458,
Yep, the .408 Cheyenne Tactical is a .505 Gibbs necked down for .408-cal/400-grainer and the case shortened by about 0.1" and given a shoulder that looks to be about 20 degrees like the .338 Lapua and the .395 Tatanka.

19 March 2007, 23:47
SuperSpeedI think Saeed has the 416 Rigby Improved necked to 475. On the non forum part of his site I think he has some top groups whot with.
If memory is working for me he comverted a Dakota 76
20 March 2007, 00:51
Paul Kquote:
Originally posted by Robgunbuilder:
You can headspace off of .010 with no issues. I have built two .470 Mbogos. they are great!-Rob
Thanks Rob, I didn't know just how much of a shoulder you needed to have to head space off of. I personally just want to neck up the Rigby case to .475. I think this will give me all i need. A poor mans 470.
Paul K