Can a 500 Jeffery be built on a left-hand Ruger 77 originally chambered for the 300 Win Mag or 7mm Rem Mag ? This is not the Ruger Magnum rifle usually seen in 375 H&H, 416 Rigby, or 458 Lott. This is the shorter action available in left-hand.

Hammer

The 500 Jefferys can be built on about any standard length action, most were built on the Mauser m-98.....It requires some opinning of the action and I would suggest a drop box magazine and that requires a new stock or if you don't mind a little ugly you can use the same stock..

Hammer,
The action will need opened up to the rear to accomondate the ~ 3.56" COL of the Jeffery cartridge. Also, a new magazine box is almost mandatory. As Mr. Atkinson pointed out depth of the box should be increased, but the width of the box must also be increased to obtain proper feeding. If you do not opt for the drop box magazine capacity will most likely be 2.

You will need a magazine box with widths in the following ranges if you desire a staggered magazine, which feeds well:

Rear of box: 1.05" to 1.07"
Front of box: 0.95" to 1"

I am sure these are much wider than your current box. If you want a single stack, you still need a custom box as the stock box is too wide.

The bolt face must be opened up, which is not a big deal. Keep in mind, and this is somewhat important, since you are starting with a 300 Win mag the bolt face depth SHOULD/DOES NOT need to be altered. However, the extractor will need to be opened up. This is important since the distance from extractor to bolt face greatly influences the ejection characteristics of your rifle.

The feed rails will need adjustment, probably significantly. Again not a big deal, but can take a considerable amount of time. Remember "haste makes waste".

Feed ramp will need to be widened and blended into the new magazine box. Again, like the feed rails not a big deal, but time consuming and tedious.

Don't forget to install a second recoil lug on the barrel about 5" - 6" forward of the receiver recoil lug.

Steel bed the entire length of the action and forward up the barrel to the second recoil lug.

Cross bolt behind the receiver lug (square bolt is the best) with the lug bearing directly against this cross bolt. Second cross bolt rear between the magazine and trigger group mortises (not sure if this is possible with a Ruger M77). A third cross bolt can be installed behing the rear action screw, again the action screw should bear directly against the cross bolt.

Leave at lease a .03" clearance between the tang and the stock (visible gap). This is not bad inletting, what it is is allowance for stock compression during recoil. The magazine mortise will breath (sides bulge out) and this will allow the receiver's tang to wedge the stock if insufficient clearance is there (like splitting firewood).

I am sure I left out a few things, but that should get you started.

If you go forward with the project, I wish you the best of luck.

Scott

There is a fellow who sometimes posts on these boards who built a 500 jeffery on a rem 700. You might want to ask him what he ran into.

Personally I would save my money and get it done right on a mauser. A 500 jeff done right on a mauser will have good resale value. On a model 77 or model 700, it will have little resale value.

Would you use a left-hand Dakota Safari, a Montana 1999 PH, a Granite Mountain Arms, or some other left-hand Mauser variation ? I do have a new-in-the-white left-hand Matheui action which has a magazine block in it to make it short enough for a 375 H&H.

Hammer

I have not handled a MRC, so I will defer that question to someone who has.

But I would in an instant use a Dakota or Granite Mtn instead of a Ruger. If you are using a Dakota Safari action or a Granite Mtn, then you could fit in the 500 A-Square which is quite a bit easier to work with than the 500 Jeffery from a feeding perspective. Of course the initial investment in the rifle is higher, but the end result is far more appealing.

500grains,

I agree that the Dakota and/or Granite Mountain action are vastly superior options than the Ruger M77. Having stated that, I must disagree with your comments regarding how the 500 A Square is a more desireable cartridge than the 500 Jeffery. The 500 A Square lacks both the power, and more importantly, the class of the 500 Jeffery. Having owned, at one time or another, both cartridges I know of what I speak. BTW, the feeding issue is grossly over exaggerated. The Jeffery requires a wider magazine box, that is all.

Finally, if it comes to resale, the Jeffery will hands down beat the A Square, which is practically a wildcat, and not overly appreciated by the pocketbooks of those looking for a class act 50 caliber hunting rifle, at least not in my experience.

If one is actually hunting there is little or no actual terminal ballistic differential between them. Though the Jeffery will operate at about 10% lower pressure, for whatever that is worth.

Scott