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Did not know which forum to post this too, but this seems to get the most use ,so I see the term used quite a bit “load to black powder performance “ Whatis that? I looked all over for FPS of 45/70 with different weight bullets, using black powder. Does anyone know where there is a chart of speeds for 45/70 using black powder. Nothing in my loading books, & couldnot find anything with google
Many manuals have a “trapdoor” section which are black powder pressure level loads. These are typically 16,000 psi or less, to be safe in elderly rifles of antique metallurgy.
They will not be listed by speed, but by pressure.
Unless someone is selling black power cartridges loaded,I think all the .45/70 government sold today have light loads of smokeless powder in them. So be careful of them.Quote:
Originally Posted by rintinglen
Black powder can vary a lot, so it will be hard to get exact figures unless using same, gun, projectiles as well as amount and type of powder, temperature and humidity of the day.
Classically speaking: a soft 405gr plain-base bullet at 1,200 - 1,250fps
Replicating the M1873 service load using the lee 405HB over 70 gr of 3 different types of BP I measured the velocity (24" barrel) at 1250 - 1350 fps. The measured pressure ran from 18,000 to 25,000 psi.
Some casters are filling their first half, of their mold with pure lead to mushroom quickly and the part that does the driving, with really hard lead. You might give that a try. You could even hollow point them.
Thank you Larry, that is what I was looking for. If I push the Lee 340 around 1400 to 1500 I should be close to what a black powder load would be. That is the only mold I have for 459 right now..I have several kinds of powder so will try different ones at that speed & look for best accuracy.
I can't seem to cut and past the original, but this is what Phil Sharpe listed as 45/70 performance numbers. I will list some of his results with original powders that are still in production with A COUPLE OF CAVEATS ... 1) Phil did not produce these results he had input from others, so we don't know the full derivation of the loads ... 2) Phil could have mis typed, there are a number of typos in his book in the load data section that are obvious, who knows what else... 3) Phil stated that 25,000 was the safe limit for antique guns, and you can see that he tried to do a reasonable load and then what was a very max load... 4) None of this was done for a particular rifle ... 5) The pressure measurements are consistent and standard for the day, but they are NOT THE SAME as our modern pressure levels for a number of reasons I can't explain except that they are different types of measurements and we have some more sophisticated tests these days. In other words, the pressure figures are comparative within the data, not outside the reality of 1937.... 5) This data is historical information, your results WILL vary... 6) Finally, I did this so you can see some velocities to work your loads from velocity wise. I think the BEST MODERN place to start is with Paco Kelly's results which cover Load levels 1 - 4 (what I call tiers, it's his data so he's correct).Quote:
Originally Posted by Yooper003
https://www.leverguns.com/articles/p..._leverguns.htm
From "Sharpe, 'The Complete Guide to Handloading' (1937/41) pg 400-401
500 Grain Fg Black 70 Vel 1320 Pres 25,000
240 grain - unique 15gr velocity 1648 Breach pressure 12,300
240 grain - unique 20.8gr velocity 1972 Breach pressure 24,000
300 grain (JSP for the 300s) - 2400 24 gr velocity 1560 Breach pressure 13,500
300 grain - 2400 30.6 gr velocity 1905 pressure 24,000
300 Grain - Unique 13gr Vel 1330 press 12,000
300 Grain - Unique 18.7gr Vel 1685 Press 24,000
300 Grain - 3031 48.0gr Vel 1675 Press ???
(Mike's note - traditionally, 3031 would use the 40% rule in a trapdoor which would put the equivalent at 28 grains of 3031 for 70 grains Black. The same goes for 4227 also a semi bulk powder and I would not start over 28 grains, with 4227. Phil said this was a DuPont load, who knows the pressure but that definitely doesn't seem like a tier 1 load. Although neither 3031 nor 4227 are dynamite)
300 Grain 3031 58gr Vel 2015 Pressure ???
344 Grain Unique 14.0 Vel 1335 Press 11,700
344 Grain Unique 19.0 Vel 1598 Pres 24,000
405 Grain 2400 22.0 Vel 1290 Pres 14,000
405 Grain 2400 27.4gr Vel 1560 Pres 24,000
405 Grain Unique 11.0 Vel 1133 Pres 12,300
405 Grain Unique 17.3 Vel 1472 Pres 24,000
500 Grain Unique 11.0 Vel 1020 Pres 11,600
500 Grain Unique 17.2 Vel 1330 Pres 24,000
500 Grain Fg Black 70 Vel 1320 Pres 25,000
I hope that is helpful. Remember, these are not MY loads or results, they are merely Phil Sharpe's published data from 80 years ago. Keep doing the research and start low and work your way up in a careful, competent way.
Hope that helps,
Mike
You can see what I uploaded that for the 344 grain (which is lead in the original data) 1400 to 1500 should be in the range and leave you with some room to spare. Although I would make sure of the trends of the general pressures for the powder you are using. Too bad he didn't have some 2400 data although you can extrapolate that most likely... What guns might you be loading for?Quote:
Originally Posted by Yooper003
Mike
Another great discussion with A LOT of data on BP equivalent loads ...
https://www.levergunscommunity.org/v...ic.php?t=27410