Dear All,
I've just started casting for my NEF BC in 45-70. This is my first BIG BORE rifle. I've casted for my 45 ACP and 44 Mag for years using Lee molds, with great results.
I made a sort of personal commitment to only ever shoot cast projectiles, preferably my own, in this firearm. I melted those super soft stick-on WWs [almost pure lead?] in a Lee bottom pour furnace. I did the obligatory mold smoking preperation, but still had a little trouble getting a decent fill-out in both 405gn Hollow Base and 500 gn Gas Checked Lee molds. Normally I'd just crank up the heat and keep both molds going, then cull the suspect looking projectiles.
Instead, I decided to try pressure casting [correct term?], by placing the sprue plate fill hole right up against the pour spout when filling the molds. I'd done this before with the other molds, but experienced indifferent results. Not this time! Pressure casting for these big molds produced excellent results, and very few reject projectiles.
Does anyone else regularly use this method, particularly to fill big mold cavities?

I used 16 gn of Blue Dot with the 405 gn bullets, sized and lubed with a home brew paraffin/vaseline/beeswax mix. The Blue Dot burned very cleanly. I tried 40 gn of AA-3100 behind the similarly sized and lubed GCed 500 grainers. What a mess. While no leading was evident, the amount of unburned propellant was troublesome. The case ejector helped spread unburned AA-3100 granules through the mechanism. In future I'll have to shake those unburned granules down the barrel before opening the breech.
I know both loads are very mild, and the BC can handle 450 Marlin style pressures. Increasing the amount of AA-3100 should theoretically help with combustion, but I think I'd rather stick to relitavely pedestrian velocities with those big chunks of lead.
The factory peep sight was surprisingly accurate and easy to use. I can only summarize my whole experience as a ton of fun, and more so than with any other rifle I've owned.
Albatross.

Try 3031 behind that boolit.

I have the Lee 405HP mold too. It makes very nice bullets. I use the "pressure" method amd I go one step further; I let the sprue solidify between the ladle and the mold. I figure it lets the mold draw all the lead it wants into the cavity as the bullet cools.
Right or wrong, it works for me.

I have had mixed results trying to bottom pour rifle bullets. Sometimes they look absolutely perfect until they are weighed, and then the weight variance shows up.

I would recommend you ladle cast for your 45-70...

quote:

Originally posted by bfrshooter:
Try 3031 behind that boolit.

And some RE 7-I've gotten great results with cast bullets in the .45/70 with both of these powders! The less airspace you leave in the case, the more uniform your velocities and groups will be!

A little more on "Pressure Cast" 45-70 projectiles in my NEF Buffalo Classic:
I decided to put a Sightron S-1 3-9 x 40 scope on the BC, after reading some very favorable reviews regarding these scopes. [The appeture sights were good, but my corrected myopia proved too limiting]. This is a nice bright scope, and it's even "Made in Japan". Mounting was a breeze, though removing the factory front sight took some effort.
My best results, after sighting in, where with Lee 405gn HB projectiles, cast from air cooled pure [stick-on] WWs, tumble lubed with Liquid Alox, and propelled by 16gn of Blue Dot.
At 75 yards I had 2 x three shot groups with all the bullet holes touching. I'm still in the early stages with this rifle and cartridge. Wow!
I used 13 gn of Blue Dot for the 500 gn sized and GCed projectiles. I'd get two bullets virtually into the same hole, then a flyer. I didn't weigh any bullets, so the problem may have been due to internal fill out, or any number of other factors. At least Blue Dot burns very cleanly.
Considering I've yet to experiment with various alloys, velocities, and propellents, I'm pretty happy.
Cleaning the rifle was no chore at all. Perhaps I didn't shoot enough rounds to get any significant leading.
I'll try some slower burning powders once I get my casting under control. I think I'll load some tumble lubed unsized 500 gn, without GCs next.
Cheers, Albatross.

Albatross, try the RCBS 45-500 BPS bullet. It is flat based, and shot extremely well unsized and pan lubed with Emmert, to one hole at 100 with 27 grains of AA 5744.

Good luck!