I recently picked up a ruger no1 in 50-140. It came with several hundred 580gr cast bullets and a few dozen brass. I would like to find load data using jacked bullets in the 500-700gr range. I was told this has a .510 bore but I haven’t slugged it yet. It did have 20 rounds loaded with a 700gr jacked spirepoint and a kodiak bonded box with same bullets. They were all .510”

I’m looking for some smokeless powders load data and any other experience some of you hopefully have with this chambering. The rifle has a heavy 22” barrel with the last 2” ported. I would have rather it wasn’t ported.

Thanks

Nice RIFLE FOR DINOSAUR !

Look up the ".510 Nitro Express" in COTW, 16th Ed., pp. 310 - 311.
Same thing as the 50-140 Sharps 3.25" but loaded like you want to do.
D'Arcy Echols built it for Bob Schneidmiller on a Martin Hagn falling block action.
Bob's data in COTW, no barrel length specified, and not to be considered starting loads:

500-gr SP/FMJ ... IMR-4895 90.0 gr ... 2337 fps
550-gr SP ....... IMR-4895 88.0 gr ... 2172 fps
600-gr SP ....... IMR-4831 102.0 gr ... 2053 fps
700-gr SP ....... IMR-4350 85.0 gr ... 1942 fps

What is the twist rate of the barrel ?

A 700-gr jacketed spire point sounds a lot like a 50 BMG bullet, usually requiring faster twist than recommended for the short 580-grain cast bullet.
I find it interesting that someone has picked a twist rate that seems to work for both.
Please do tell what that is.

A relative case capacity comparison is below.
You could use the smaller-cased 500 NE 3" starting load data with filler in your rifle,
and work upward to tolerance of you and your rifle.
40,000 PSI loads should be plenty of fun if you have brass that can handle it.

500 Jeffery 2.75": 158.6 gr H2O

50-140 Sharps 3.25": 157.3 gr H2O

500 Mbogo 3-Inch: 153.5 gr H20

500 NE 3-Inch: 147.4 gr H20

500 A-Square 2.90": 146.8 gr H2O

In my 500 Mbogo 3-Inch, I used a 777-gr FNGC hardcast (NEI mould) with H4831SC 100.0 grains >>> 1760 fps in a 25" barrel.

That would probably be a good powder charge for your 700-grain jacketed bullet. Start with 90 grains and work up to satisfaction. Use a filler too. Dacron fluff or foam wad ...

Thankyou for the information. I’ll check the twist rate. The 700gr bullet was fairly short and blunt. This is the 700gr bullets and a dummy I made up next to a 30/06 for scale.

Beautiful rifle, but get ready. You are not going to believe how hard that thing is going to kick. There IS a reason the guy sold it----

What twist barrel?

Looking forward to your experience with this rifle.
I have a #1 in 50-110 with which I’ve played with anything from pretty hot loads to NfB and even Black Powder. Jacketed, cast and paper patched.
It’s a really fun rifle but I’m thinking of rechambering to 577/500 No.2 or 577/500 Magnum and working up genuine nitro loads.

I just might have some more brass if you're interested, not much say 15 new cases

I also have some Dies but you must have some

Excellent rifle and cartridge. It should have moderate recoil with that brake.