View Full Version : rechambering a Ruger #1?

Deja vu
May 30, 2012, 11:41 AM
I have been dreaming about a 550 magnum (the round not the gun). Do you think a Ruger #1 could be re-chambered and have a new barrel on it so that it could shoot the 550 magnum round?

Magnum Wheel Man
May 30, 2012, 01:55 PM
you could probably put any barrel on it... the critical points would be the barrel thread size on the reciever ( it would have to be big enough ) I'd suspect it would be of sufficient size on a #1... & also that the bolt face is large enough... I'm not really familiar with the 550 magnum, but also suspect that there is room there as well...

so long as both are big enough, then likely the hardest part is finding someone to do the work... & of course paying for it...;)

just did a custom rifle in 416 Rigby myself ( re-read that, & sounded like I did everything... in reality, I did the planning parts sourcing, & paying parts... my local retired machinist buddy did the hard part )... anyway... I always wanted one :)

May 30, 2012, 02:58 PM
I suppose it could be done. Since I value my shoulder, I think I'll let someone else shoot it though

Clifford L. Hughes
May 30, 2012, 04:38 PM
Deja Dvu:

What is the 550 magnum and what diameter bullet does it shoot?

Semper Fi.

Gunnery Sergeant
Clifford L. Hughes
USMC Retired

May 30, 2012, 04:55 PM
The .550 Magnum is a wildcat based on a blown-out straight-walled 460 Weatherby case. It fires a .550" bullet weighing from 600 gr to 700 gr.

May 30, 2012, 05:37 PM
I don't think there is enough room. That's an awfully big case.

May 30, 2012, 06:45 PM
Considering the #1-H aka Tropical is currently available ine 450/400 Nitro aka 400 Jeffery Nitro express, you have an action that can have from the factory a .613 breechface, a 3" long chamber, and .545 base diameter. Also considering that the #1 has been offered in 416 Rigby in the past (the parent of the 378 / 460 WM) you can easily handle the brass part of the cartridge. If I were to go this route, I would look for a Rigby version as the breech is already set for that diameter rim. The #1 has never been accused (to my knowledge) of being incapable of handling lots of bolt thrust. If a CZ 550 can handle this round, so can a #1.

May 30, 2012, 08:00 PM
I believe Ruger #1's have different extractors which have to fit the extractor cut in the barrel. It isn't so much a bolt face issue, as the bolt is a falling-block.

I think one extractor fits a "range" of calibers, and if you can get a Ruger #1 set up for something with a similar head diameter, a properly cut barrel should permit the extractor to work. If not, you may be looking at a replacement extractor as well as a new barrel.

(At least, that's what my gunsmith said.)

May 30, 2012, 08:58 PM
I've looked into this a little. The No. 1 will work fine, you will need the 416 Rigby ejector. The 550 Magnum case is essentially the same as the 416 Rigby with a belt. All No. 1 actions are the same, however some have more clearance than others when the block is lowered. You may find after the conversion that the belt hangs on the top of the breechblock when you eject the case (mine did very slightly).

Now the bad news: having owned a No. 1 in 460 Weatherby I can tell you that recoil with anything approaching full power loads will be unbearable. A No. 1 is a light action and due to the required barrel contour it's really hard to make a heavy No. 1 (did you ever wonder why the Tropicals have such heavy barrels and still weight under 9 lbs?). The classic stock is not designed for heavy recoil and the stock pad is a joke. But those items can be changed.

Before you spend any money I suggest you shoot some full power 458 Lott loads from a No. 1, then re-evaluate the project. If you still want to move forward good luck!

May 30, 2012, 11:57 PM
Second that advice, I've fired mine in .45/70, .458 Magnum, .405, and .450/300 Nitro, and tried another in .416 Rigby. I can handle the recoil, but it's not something I want to do more than 5-6 rounds at a time...

May 31, 2012, 12:18 PM
I would also look in getting an ATF letter for a sporting exemption to the DD rules before building it, with a rifled barrel over .50 it falls into that classification.