That is sort of like my old Berry's Bullets 409-gr/.459" FN grease lubed bullets, except mine are plain-base, have no copper-washed/plated base treatment.
Your Ruger No. 1 is .459"-grooved like mine, I reckon. It will shoot those bullets with OK accuracy only if you keep the velocity down to about 1200 fps. Mine key-holed at higher speed too. I used 26.0 grains of AA-5744 for a 7-yard instrumental velocity of 1172 fps and 3 shots into an inch at 50 yards.
Nice plinker, barely supersonic. Accuracy will get worse until keyholing assuredly at 1500 fps instrumental.
Alternatively: Degrease them and powder-coat paint them to make them 0.460". Still not the desirable 0.461" for best accuracy.
Alternatively alternatively: Shoot them in a .45-70 with .457" grooves using smokeless loads. SAAMI spec for .45-70 is 0.456" minimum groove, so you will find them with groove diameters from .456" to .459" and hopefully no greater than that
Too hard and Too small. Too hard to bump up with powder to the rear so you will have to ride the bore at low speed. Or if your good with a Hammer, take them out to the anvil in the Blacksmith's shop and whack them with a Two Pounder until they are .460+ enough to size again. The Hammer Test 2.0
The Hammer Test 2.0
