Considering getting a mold for my Ruger #1 in 450/400NE to shoot a GC bullet in the 350-400gr. range.
Are there bullets that work really well? Size to .410 - .411, possibly a bore riding front design?
I realize that Gas Checks are hard to find in this caliber, but I am looking at Gator GC - are the heavy ones or the thin Lyman design preferable? Any input appreciated.

Vasa

Cannot speak to your exact caliber but in the 400 Whelen, "modern" .411/40-82 (400 whelen plus P ballistics in an 1885 Highwall) and 400 H&H the NEI 411-350-GC casts out at 375 gr in my double cavity mold and will shoot sub MOA in all.
Pushed to 1800 fps or so, it is also a fearsome killer.

Order the mold with the optional "DD" feature ( a front driving band that aligns the bullet by "biting" into the rifling)

I use .416 Hornady gas checks in a SAECO lubesizer with SPG lube.

I have shot 12" gongs out to 400 yards in all three guns, off bipods, and it's just "bang, clang".

Don't have pic of this bullet, but have the same design in 30 and 35 caliber. You can see the driving band at the front of the bullet. You might want to do a chamber cast & the 1st 1" of rifling cast with cerrosafe to see what diameter to make the driving band as your single shot has no camming power to force a too fat band into the rifling. Driving bands are nothing new and were around in the Scheutzen days when the bullet was seated into the rifling with a rod device (from the rear) followed by the unsized charged case being loaded with either a wad over the powder or the muzzle elevated.

This is the 35 and one recovered from a wet gumbo dirt bank @300 yards.



I now have No. 1s in 450 NE #2 3&1/2" and 458 Winmag and an 1885 Highwall in 45-70, so I'll be sending NEI an order soon for the 458-440-GC-DD

Their website is:
http://www.neihandtools.com/catalog.html

and go to the "old catalog" pictures.

Once you use a quality Aluminum mold, you'll sell off all your cast iron ones !

Order some 'test' bullets from Montana Bullet works or Beartooth Bullets. I use them in my 416 Taylor @ 1800 fps. Very accurate, fun to shoot and penetrate very well.

Good idea if you don't wish to cast. They have several NEI designs.

I have a Ruger #1 450/400 and shoot the RCBS 416-350-FN sized to .412, when cast from wheel weights it weighs close to 370 grains. I also have a mold from Accurate Molds, catalog #42-380B that fits the Ruger chamber perfectly and shoots as well as any jacketed bullet. When you order the mold tell Tom that you want the gascheck shank cut for a .416 check.

Check with the guys at the Cast Boolits site. They may have a group buy on Gator checks going.

Thank you for the help, Gentlemen.
I have found molds with both NOE and Accrate. Gator checks are now also available here in Canada.

Vasa

I got a 320gr WFNGC and a 400gr LFNGC from LBT, they cast about 4125 with 1/20 blend. I have had a bit of an issue with the nose sizing and being able to use the crimp groove. It really ought to be moved one band's length forward on the nose, that would solve the issue completely. My Ruger had pretty much no throat.
So, I sized the nose to 409 to allow for springback, and 411 on the body. Lbt recommended using 416 Gators on it and cut it to suit on both. Gators are avail from Dragon Bullet Lubes, think he is in Ont. He is linked on the vendor header on CGN. I also got a Lyman M die expander for a 405win from him, came with the 410/412 expander in it. Works great. Picked up a 409/411 custom expander from Buffalo Arms, and the sizer dies for the 450 lubesizer.
One thing I did try that was a bust, was a Saeco 400gr mould, would not cast bigger than 4105, and I did 5 different blends in it to get it up to size. They said it would hit 412, didn't happen for me.
Quite sure Veral can add an extra band to move that crimp forward, I just didn't feel like sending them back, to do that, at the time.