Calculateingz powder load on smooth bore rifles

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Next week will be my first attempt at shooting a smooth bore rifle, specifically a TC New Englander 12 ga. I’m familiar with the loading process but need to confirm what I’m told is the proper way to determine powder load. Most of what I read about BP in shotguns is that the amount of powder is determined by and should equal the volume of the projectile(s). I plan on using slugs to start with 0.8 oz slug. Using Pyrodex RS, the equal amount of volume is 58 grains of powder. My experience with rifled hardware tells me this is a very light load.

I’d like to use a distance of 25 & 50 yard to targets. My intention is to load powder, over powder wad, slug, over slug wad.
 

SmokepoleSam

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That volume of pyrodex is equal to 87grs of black powder. We use volume measurements to keep the pressure levels the same for the different powders.
 
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If going with the old adage that powder charge is equal to bore diameter, then .715/12ga bore would be a 70 grain starting point.

Many times, be it ML or centerfire, lesser charges produce better accuracy.

Good luck with it.
 

smoothshooter

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Next week will be my first attempt at shooting a smooth bore rifle, specifically a TC New Englander 12 ga. I’m familiar with the loading process but need to confirm what I’m told is the proper way to determine powder load. Most of what I read about BP in shotguns is that the amount of powder is determined by and should equal the volume of the projectile(s). I plan on using slugs to start with 0.8 oz slug. Using Pyrodex RS, the equal amount of volume is 58 grains of powder. My experience with rifled hardware tells me this is a very light load.

I’d like to use a distance of 25 & 50 yard to targets. My intention is to load powder, over powder wad, slug, over slug wad.

Don’t overthink it.
Start with one grain ( weight ) per caliber and work your way up from there.
 

TDM

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SmokepoleSam, if I can play back what you said; when I use a powder measure set at 87 and fill it with Pyrodex, I would be using 58 grains of Pyrodex?
@Grenadier1758 explains the difference. But I wouldn’t get to hung up on the weights. Unless you’re match shooting or just really hung up on precision measurements just measure by volume. If a load calls for 80 grains of BP, set your adjustable measure for 80 and fill it with Pyrodex. (If you must ;) )
 
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@Grenadier1758 explains the difference. But I wouldn’t get to hung up on the weights. Unless you’re match shooting or just really hung up on precision measurements just measure by volume. If a load calls for 80 grains of BP, set your adjustable measure for 80 and fill it with Pyrodex. (If you must ;) )
Thanks, I’ll take that advice….I get the hint, but can not find black powder anywhere.
 
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The use of substitute powders such as Pyrodex and Tripple Seven in percussion firearms is better than nothing when only a pound is needed at a time and black powder is not available. Being fine can be debated when performance is compared to black powder, but being able to make smoke can end that debate quickly.
 
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