I know loading muzzle loaders that black powder is measured by volume not scale weight. Is it the same with black powder cartridges? ie 30 grs. by volume for .45 Colt.

mcg6637,

I have come to the conclusion that the reason b.p. is recommended to be measured by volume is because not all black powders have the same density. In other words an = volume of Goex and Swiss typically do not weigh the same, and there can even be differences between lots.

For example, if I set my powder measure to dispense a certain volume, these are the actual weights in grains of the powders / lots I have on hand:

Goex FFG = 40.0
Kik FFG = 38.2
Swiss FFG = 45.2

I have found the best thing to do, is to determine what volume is required for my particular application. I shoot a fair amount of .44-40 and .45 Colt b.p. cartridges.

If I'm using Goex, I like a volume that will require a compression of .18"-.20" on a settled powder charge. If I'm using Swiss, I shoot for about .06-.10 compression of a settled powder charge.

Once I have determined the volume needed of a certain powder, I will weigh it for reference. Then, when I load additional cartridges using that same powder and lot no., I will double check the actual weight to make sure that the powder measure is set for the correct volume.

I can then choose to either weigh each charge or load directly from my powder measure set at the required volume.

Works every time. :D

John

Just what I thought, thanks. Having never done BP cartridge loading before, of course I hear a lot about just loading the case till it's full. However to get the right powder load do you start with max cartridge OAL then add and subtract powder column height, bullet height plus - say 1/16" for compression? Can I assume that since the original .45 Colt load was 30 grains of BP over a 250 gr. RN bullet, if using actual Goex BP the math would work out correctly?

I just got a lesson about this subject.I recently bought a new in line MZL,and,because my classic MZL hadn't been used in years,I lost the powder measure.I proceeded to weigh over 30 charges in several weights,and stored them in plastic vials.
When I bought a new powder measure,I decided to see what the differnce would be.
My 90 grain weighed charges wereover 100 grains in the volumetric measure.
My smallest vial,62 measured grains were just about 70 grains by volume.
This is with Pyrodex.
Frank

777 is 15% hotter than Bp.

mcg6637,

The original .45 Colt did contain 30 grs. of b.p. but a filler may have been used, because by the early 1890's U.M.C. was producing .45 Colt b.p. cartridges with 40 grs. of b.p. Powder compression in dissected specimens was .20+".

Regarding compression, what I do is to take a fired casing and use the expander die to iron out the crimp. That will allow the bullet you are using to produce a sliding fit in the case neck.

For the .45 Colt, I would suggest starting with a measured 35 gr. by weight charge of authentic b.p. (not the subs ....777, Pyrodex, etc) and dump it slowly (about 5-6 seconds) through the funnel into the case. That will settle the powder. Place the bullet into the case down to rest on top of the powder. Measure the overall length. Adjust the powder charge for the amount of compression that you desire.

For example, let's say that the desired overall cartridge length is 1.59".
For 1/16" compression, the cartridge length with the bullet touching the correct volume for that compression of b.p. would be 1.67" (1.59" + .06"). Personally, I prefer a minimum of .18" compression with Goex. I find that it works better for me that way. I use the expander button (Lyman "M" die) to compress the powder.

BULLET:
For authentic b.p., choosing the the right bullet that holds enough of the right lube for b.p. is key. The only single lube groove that holds enough lube for authentic b.p. in a rifle length barrel is the "big lube" type. For handguns, the earlier two lube type would be preferred over the standard smokeless bullet with 1 small lube groove.

You can purchase the PRS "Big Lube" .45 Colt bullets from http://www.whyteleatherworks.com/
Click on accessories and go to the bottom of that page.

Kragman71,
Thank you for telling your experience. I have 2 good b.p. measures...an older Lyman 55 and a Belding & Mull. Both have settings for 40 grs. volume of b.p. BUT there is a 9% average weight difference between them with the B&M throwing the heaviest charge. Hmmmmm.......

bsn,
That is true when 777 is compared with Goex. Swiss b.p. on the other hand is a "Sporting Rate" burn powder and I have found that it will produce ballistics on par with 777 along with the flames (which 777 can't).

John

Ditto what John Kort said and I'll add that I run the powder into the cases with a 24" drop tube, pour slowly.