Triple 7 in .45-70

[Smith357]

I'm trying to work up a load for a trapdoor

My current components are:
405 grain hollow base, round nose bullet
nickel star line cases
Federal magnum primers
Hodgden Triple 7 FF

My problem is Triple 7 is not supposed to be compressed, yet the recommended (starting) load is 60 grains for a 405 and that much powder would be a heavy compressed load. To load the case to the proper "full but not compressed" spec that Triple 7 calls for, I would only be using 45 grains and even less if I use a card.

Is 45 grains of Trip7 by volume enough umph to get a 405 grain bullet down the tube of a trapdoor and break the paper 100+ yards out?

 

[Ratdog68]

Question... is the 60 grains called for... the spec for BP? If so... do not forget to consider that you will be reducing your load by 15% when using 777 powder to equal the spec'd load.

 

[arcticap]

Once the proper amount of powder and compression is determined then loading 777 with compression should work out.
The coarser 777 ffg allows for some extra compression, and 777 is made in highly compressed pellet form which you wouldn't be matching the density of.
There's always 777 fffg to try or 66 grains of APP with a 405 grain bullet like DutchmanDick and others prefer to use to replicate BP velocities.


http://www.thehighroad.org/showthread.php?t=219629&highlight=.45-70+APP

 

[fineredmist]

The original .45-70 cases were ballon type without the heavy web at the base which modern brass has. There was a lot more interior space so it was not a problem to get 70 gr. of powder into them. I have loaded 60 gr. of 2 f with a solid base 405 gr cast bullet and it works just fine. That load gives me 1300 fps +/- 25 which is what the original loads produced.

 

[BHP FAN]

55gr. of 2f [the original carbine load,70 was for full length rifles] works pretty good in mine,useing a wonder wad under the 405 bullet.

 

[Smith357]

55gr. of 2f [the original carbine load,70 was for full length rifles] works pretty good in mine,useing a wonder wad under the 405 bullet.

This is good, I'm loading for a carbine. I'll have to work out the 10-15% reduction math on paper. to see if the numbers all match up, argh, math.

The original .45-70 cases were ballon type without the heavy web at the base which modern brass has. There was a lot more interior space so it was not a problem to get 70 gr. of powder into them.

Thank you for letting me know why my volumetric measurements were not jiving. It's all starting to make more sense. All I need to do now is crunch the numbers and gather the final components. (wads)

 

[Ginormous]

argh, math

Math (calculus) is so derivative.

 

[zimmerstutzen]

Trip 7 is ok. But frankly, when you are down to the point of being consistent (fussy) about brass and primers, and weighing each bullet to make sure they are within a few grains of each other, all the mentioned consistency goes to Heck with trip seven. For all it's benefits, it just isn't that uniformly consistent for fine target accuracy. Holy black is. If you want short range hunting accuraccy (to 200 yds) , trip 7 is fine.

A trapdoor is blessed with certain inherent accuracy problems anyway, such as the thin barrel walls and barrel bands which affect accuracy as the bore heats up. My 1884 will settle in to fair groups, but starts 14 inches low and left at 200 yds from a cold barrel and doen't start shooting on the mark until about 5 shots have been fired. If the barrel cools down between relays, it goes back out again. Even when warmed up, the gun is only good for 6 - 8 inch 5 shot groups at 200 yds. Not bad hunting accuracy but not a Scheutzen gun either.