Truing the Enfield Receiver Ring

Below photo shows a stripped 1917 Winchester Enfield action with the truing mandrel.

Below photo shows the action mounted on the truing mandrel and set up between centers in the lathe. The tool bit will be moved out, 90 degrees to the axis of the receiver, as the action is rotated. This faces the front of the receiver ring flat and at a 90 degree angle to the action, and later installed barrel, centerline.

Below photo shows the bottom of the Enfield action and several 50 caliber cartridges and bullets. The cartridge in the action opening is a 50-110 case with a 535 grain Woodleigh seated. COL is 2.935”. Note this is a softnose bullet with the exposed lead turned off, giving a flat nose bullet.
Cartridges below the action: 450 Rigby with the bronze solid. 460 Weatherby with 500 grain softnose. 510 A-Square with a 600 grain cast lead bullet.
Cartridges above the action: 500 Nitro 3-1/4” with another trimmed Woodleigh. 500 AHR with 535 grain Woodleigh SA. 500 Jeffery with 535 grain Woodleigh SN.

Bullets to the left of the action: From bottom: The trimmed Woodleigh, now weighs 505 grains. Then a 535 grain Woodleigh SN. Then two 535 grain Woodleigh PP. The next two are cut down 50 BMG bullets with the base now used as the front. One is solid bronze at 400 grains with bore diameter grooves cut into the shank, the other is a lead core steel jacket, moly coated, at 500 grains. Top bullet is the original 50 BMG moly coated.

Details on the cartridge on the action: With the bullet seated as shown, this case holds 103 grains of powder. At 15 feet from the muzzle, velocity was 2486 ft/sec, with a pressure of 59,313 psi. Energy was 6958 ft/lbs. So you can see why I terminated the project, this cartridge will chamber in a 1886 Winchester and other old weak 50-110 rifles!

You will note the opening in the action is longer than the cartridge, actually around 3-1/2 inches. This is the original unaltered 1917 length. Back when I was doing this work I was thinking of using a 500 Nitro case, trimmed a little, to give me a COL to match the action opening. My QuickLoad calculations gave me over 8000 ft/lbs with this combination, all with a 22 inch barrel. So there is a lot of potential here. If I get back into this project, I will run the numbers with the 500 AHR case, as it has a very large powder capacity. The problem with using a trimmed 500 Nitro case is it would chamber in a 500 Nitro double Rifle if the rim was maintained, and I would have the same problem as with the 50-110 cartridges: Instant gun wreck if the cartridge fell into the wrong rifle! The 500 AHR or the 500 Jeffery likely would be the best cartridge for the bolt action. Maybe the 510 Wells or A-Square.

The problem as I see it with these big bullets at over 2400 ft/sec is the recoil gets to be quite stout.

Anyway, lots of room here for experimentation. I may return to this project in the future, but my gun building backlog now has too many projects!