I'm in the process of reboring my 375 H&H RSM to a bigger Bore. Can anyone who has shot these rifles offer any comments on them in the feild. The Jeffery seems to be very expensive all around. (lack of factory Ammo, Lack of bullets,expensive 1" reloading dies...) If there is a big difference on Buff's it might be worth it?

Thanks

Brad

If I was going to go to a .50 cal, I would do the 500 A2...uses .460 Wthby brass, and much easier to get to feed.
I like the 450 Rigby, as it is just a beltless, standard shoulder .460 Wthby, which in turn is a belted, strange shouldered .416 Rigby necked up to .458....Anyway, you can load the 450 Rigby from mild (2100fps) to wild (2600fps) with a 500 grain bullet. It easily attains 2300fps which is what the .458 Lott does, but at much higher pressure.

If you meant reboring not rebarreling,consider the following. I don't know what your barrel wall thickness is but 375 to 45 caliber is a good size jump. I doubt you even even have the option to jump to 50 cal. If it's even feasible, you will loose quite a bit of weight in the barrel, balance, etc. goes out the window and you now own a severe thrashing machine. If you choose a 500 Jeffery, you need to get a very, very, competant gunsmith to set up a proper functioning 500 Jeffery with the rebated rim. IMO there are only three in this country I would trust to do the job, there might be more I don't know about.

the action is large enough for a 505 gibbs ... however, the RIGHT answer is the 470mbogo
www.470mbogo.com
weight will be perfect, amazingly hard hitting round, essentially a 3" basic rigby case...

jeffe

Assuming you have a first or second generation Ruger RSM go 500 Jeffery and don't look back. The fast 50's hit far harder than the 458s and that is a fact! Of course you realize that the Ruger will only hold two down in the 500 Jeffery.

We do need to know the muzzle diameter (exclusive of the barrel band front sight) of that .375 H&H RSM to be rebored.

The First (1990) and Second (~1995) Generation RSM's in .416 Rigby have a muzzle diameter of about .810" with 24" barrel.

The Third Generation RSM (circa 2000 AD or later) in .416 Rigby has a muzzle diameter of .750" with 23" barrel. That is a well balanced rifle in .416 Rigby at 9.5# bare weight.

If your .375 H&H RSM has a .750" muzzle diameter, it could be rebored to anything up to .510 caliber, but rather whippy for a fifty. It will be a light weight: 9 pounds or less for a 500 Jeffery ... you could add 1/2 pound of lead to the butt and 1 pound of lead to the forearm ... and it would be O.K.

Thanks for all the input thus far. I have the rifle at Jim Dubells shop (Delta Gun Works) he bought the reboring gear from Cliff La Bounty's operation. Jim feels confident that he can get the 500 Jeffery to work. He has offered to build a new floor plate and magazine box to accomidate 3 rounds down. He feels there is more than enough barrel material to make it work in 50 cal. The rifle is an early RSM since the front sling barrel band is in the wood. I shoot my wildcat 9.3 RUM (Rem700) which weighs in at 7.5lbs and produces aprox 5686 Foot Pounds of muzzle energy, my Rem 416 weighs 7.75 lbs so I'm not too concerned about recoil in a 9.5 pound rifle (other than splitting my stock). But I do want it to FEED like a wiz. Jim spoke with the guys who were doing the 505 Gibbs conversions but he feels that the bolt would need too much material taken off to accomidate the 505 rim. That's why he suggested the 500 Jeffery. I am well aware of the 470 Mbogo and have strongly considered it however, like the .510 Jeffery bullets 470 bullets are difficult to find. .458 bullets and 416 Rigby brass is relatively plentiful now. I am also turned off by the cost of reloading gear when you go above .458. Hornady wants $380 for 500 Jeffery dies and I need a 1" press. I love the RSM style if I didn't I would just rebarrel an action or buy a CZ. My aspiration was to rebore the RSM into a classic african caliber to shoot and someday use it on Buffs.

Thanks

Brad

quote:

I shoot my wildcat 9.3 RUM which weighs in at 7.5lbs and produces aprox 5500 FPs

Say What???

quote:

Originally posted by bulldog563:

quote:

I shoot my wildcat 9.3 RUM which weighs in at 7.5lbs and produces aprox 5500 FPs

Say What???

I think he means ft\lbs

MY BAD you are correct. I mean Foot-pounds (Ft-Lbs) sorry typing late at night produced errors. My Calculations are based on the Nosler Reloading manual.

250grn 9.3mm bullet at 3200 Feet per Sec = 5686 Ft-Lbs of muzzle energy

Thanks Brad