Duplicate Original "Factory" BP Load

[Fox Creek Kid]

I have found that if I use RMC 56-50 cases, that I have turned down the heads to fit the Taylor's chamber, I can drop tube 2.8 cc Swiss FFg (weight approx. 44 gr.) and use my custom Tom Ballard .512 bullet (approx. 360 gr.) to pretty much duplicate the original factory load, though I'm sure that the factories back then used a "musket grade" powder & not say a "Dead Shot", "Laflin & Rand" or "Curtis & Harvey" premium "rifle" grade powder. My Tom Ballard mould has the vast majority of the weight in the nose and doesn't seat deeply in the case, yet they feed perfectly. The RMC cases use a Large Pistol primer, hence they don't have a web as thick as Starline cases & you can get more powder in them. It is however a "rip snortin'" "He man" load and hits hard. It's probably pushing over 1000 fps (I always thought the original 1200 fps was very "liberal"!  ) I will use this load this January deer hunting. The bullet has a nice big meplat and is sure to be a "pole axer"!! 

[Dakota Widowmaker]

I found that GOEX "Cartridge" is pretty close to old-timey powder. I prefer to load Pyrodex P or RS, since it is a bit easier to clean up. I am also using a modified Lee 50-70 mould cut down to 350gr, which leaves more case capacity for powder instead of lead.

I can put 45gr of Pyrodex P or GOEX FFFg/Cartridge in there with no problems at all and just a slight amount of compression. (1/8" is what I have measured)

When I switch to magnum large rifle primers, I am getting closer to the specs for what the original shooters used.
(there was so much mercury primer powder in the rims, it acted like a "duplex" load we see today)

[I have not tried a duplex load yet...this summer, I might take 4gr of Unuque behind 40gr of FFg and see how it goes. This is based on the 10:1 duplexing method some BPCR shooters swear by]

I was told by another Spencer "archeologist" that older Spencer ammo from UMC was easily capable of 1100fps with a 350gr bullet. (or there abouts...)

Each manufacturer used different components.

Winchester tended to use good powder and loading methods for ammo. (overall)
Some of the other manufacturers just took what ammounted to "military surplus" and worked with that.