Ruger RSM Rebarrel

[Shawn.54]

The actions mentioned in the RUM line would need the least amount of work but the bolt face will need a little work because the RUM cartridge has a rebated rim it is the same as all the belted mags so a little work would be needed. Standard mag bolt face is .535 404 Jeffery is .545. The 404 will probably slide into the .535 bolt face because they build in a little play but to keep the same play in 404 you need to make it a bit bigger.
Shawn
I’m in the last stages of a 404 Jeffery on a standard 98. Should have it shooting by mid February and doing all the work myself except PAC NOR barrel.

 

[geoff rath]

case diameter is the big bugbear on that one, unfortunately...

 

[ActionBob]

Instead of a Ruger RSM in 375 H&H, would it make more sense or at least be a little easier to rebore a Ruger RSM in .416 Rigby to 404 (which is really .423)?

I think the chamber would be an issue.

 

[ActionBob]

For $2700, this nice CZ in 450 Rigby, currently on GB , can be yours: https://www.gunbroker.com/Item/736233034

View attachment 213882

I saw 2 of those at a Cabelas for $1900 each... might be one of the same

 

[sandman0921]

Patience and persistence is key to finding a M70 in 300 RUM

That is for sure. They are very difficult to find. Occasionally see one from time to time on various firearms classifieds, but overall a pretty rare bird....

Before I decided to have Wayne build an AHR custom 404 Jeffery, I searched for weeks trying to find a Winchester M70 in 300 RUM, but to no avail...Ultimately I went with Wayne's DGR utilizing a CZ550 Magnum Action and I couldn't be happier....

 

[AZDAVE]

I had pac nor rebarrel the 375 RMS. the problem is as mentioned here the 1/4 rib is machined into the barrel, and the 375 and larger RMS's have a under-rib that you have to fabricate to work with the additional recoil lug system built in the stock. (If you remove the action from the stock you will see difference) You would same money and time to either have Pac-nor or barrel maker of your choice rebarrel a WIN 70. Or just buy a CZ from the factory set up from the start in 404 Jeff. You can make a RMS work but is not an easy project.

 

[sierraone]

I had pac nor rebarrel the 375 RMS. the problem is as mentioned here the 1/4 rib is machined into the barrel, and the 375 and larger RMS's have a under-rib that you have to fabricate to work with the additional recoil lug system built in the stock. (If you remove the action from the stock you will see difference) You would same money and time to either have Pac-nor or barrel maker of your choice rebarrel a WIN 70. Or just buy a CZ from the factory set up from the start in 404 Jeff. You can make a RMS work but is not an easy project.

Hi Dave, I hope your family medical issues are just history now! I could not be happier with the RMS 404 project you started and I acquired, then had a smith finish it to my desires! It will see Africa in July and with a little luck will be draw blood for the first time!

 

[ChrisG]

I would think it would be possible have the rifle rebored and rechambered. That would retain the on piece quarter rib. I don't think you would have a problem going from .375H&H to .404 J. Usually a reboring specialist will tell you that they need to have some meat in the barrel for the drill to bite into. For instance, you couldn't go from .416 to .404 because there isn't enough to remove and the bit would chatter and wander as it went down the bore.The only issue I can think of is that I believe Ruger barrels are really tough steel due to the hammer forging process. I have seen disclaimers on websites saying that it is possible that the reboring process isn't successful due to the hardness of the metal. The company would be able to talk you through it.

 

[geoff rath]

Dave, may I add my prayers for resolution of those medical issues, and good luck with the rechamber job. Changing from 416 Rigby to 404 Jeffery (did I spell it correctly?) is a no-no. the body of the Rigby is quite a bit larger than that of the 404.; the back end of the barrel would need to be removed; a real waste. try to step up from 375 H&H to 404; mucho bettero. Sierraone; I still owe you beers, or something; gotta make the 2019 AH dinner . . .

 

[BC.Pat]

RSM in 46 Rigby rebored to 450 Rigby;

did this, let me know if you have questions.
cheers
Pat

 

[BC.Pat]

That would retain the on piece quarter rib

this was the biggest hurdle in my build.

 

[ActionBob]

did this, let me know if you have questions.
cheers
Pat

Who did you get to re-bore/rechamber?

 

[BC.Pat]

I rechambered to 450 rigby from 416 rigby, I used a krieger barrel and my ginsmith machined a new quarter rib for the new barrel, so I could switch back to 416 R if i wanted to.
The gunsmith said the most involved part was the manufacturing of the rib to perfectly match the action.

Pat

 

[ActionBob]

Anyone know where to get an expanded floor plate for a RSM?

I have the one chambered in 505 Gibbs and it only holds 2, would be great to stuff three in the box.

 

[BC.Pat]

I have the one chambered in 505 Gibbs

was this difficult?

 

[BC.Pat]

expanded floor plate for a RSM

id be interested in this as well?
thanks
Pat

 

[Rick Cox]

Details on converting the RSM .375 to .404 J ? Contact AZDave, although he is having some family medical issues I believe. He had the rifle re-barreled by PacNor. I ended up buying the rifle, had my smith make some changes to meet my preferences and now have a gorgeous high end rifle which is more accurate than I am, and will be used on buffalo this July. Can't really help you with M 70 or CZ conversions to .404 JView attachment 213439

but I believe the M 70 .375 HH action is too short for a .404, where the RSM action is not. There are several other rifle actions that can be converted with other forum members knowledgeable about how to do so! Good Luck!

Nice rifle and man I love to see groups like that!

 

[sierraone]

Nice rifle and man I love to see groups like that!

Yea, I'm convinced that if I get my chance at the Buff cow in July and she doesn't go down pretty fast, if will definitely be me and not the rifle!

 

[geoff rath]

Sierraone, may I ask which bullets you'll be using? Good hunting . . .

 

[sierraone]

Sierraone, may I ask which bullets you'll be using? Good hunting . . .

Bullets....400 gr Barnes TSX, other load data from my son, (I don't reload)
powder...72 gr IMR 4064
Primer...CCI 250
COL...3.50 in
Hornady Brass
2150 FPS
Nosler factory 400 gr solid ammo shoots virtually the same except at 2300-2350 FPS