Powder weight

[jednorris]

I load 79 gr. of Swiss 1-1/2 in my .45/90 below a 480 gr. bullet. My Uniflow powder measure drops it then I weigh it on my 505 scale. I just started a new lot of powder and my powder measure threw 82 grains so I cut the measure back 3 grains. I am assuming to maintain my same load I need to be more concerned about weight than volume

[Dan Cash]

I set my Lyman measure to drop 69 grains of 2F Old Eynsford for .45-70. I then tweaked the volume until I was happy with the grouping. I have not changed the measure since establishing my load but did weigh some charges when I last loaded. The scale showed 72 gr of powder. The lots have changed over time as have the weights but the volume remains the same. Group sizes don't seem significantly different. I would recommend you stay with the volume rather than the weight and do what the target and chronograph tell you works.

[beshears]

Volume and compression is more important than weight with Black Powder.

[sharps4590]

I would have to agree with Dan. I believe volumetric fill of BPC's is more critical than whether the charge weighs 79 or 82 grs. I've been shooting Shiloh Sharps Montana Roughrider in 45-90 since 1995. The original charge weight of the old GOEX Cartridge when filled to the powder column height I wanted came to 80 grs. on the button. I've not changed the volumetric setting since but have used Schuetzen Ffg and am now shooting either it or Old Eynsford Ffg. Never changed the volume setting and haven't checked the weight since '95. I do think OE doesn't come as high in the case so maybe I should revisit the setting with that powder. If I do I won't care what the weight is other than to be able to repeat the setting.

[indian joe]

I load 79 gr. of Swiss 1-1/2 in my .45/90 below a 480 gr. bullet. My Uniflow powder measure drops it then I weigh it on my 505 scale. I just started a new lot of powder and my powder measure threw 82 grains so I cut the measure back 3 grains. I am assuming to maintain my same load I need to be more concerned about weight than volume

Shoot it and see . I weigh charges to get better consistency but I am using ungraphited stuff that doesnt run freely into measures - the target is the ultimate answer to this question - however when transferring information (joe asks fred what his load is) measure numbers dont cut it for me because your 65 grain measure could easy be 77 grains for me - tell me grains weight and I know exactly what you talkin about.

[martinibelgian]

I'm loading by weight, not volume. But loading by MV would probably be the best, IMO.

[rfd]

BP for cartridges, I weigh. BP for muzzleloaders, I measure (volume.)

[Chill Wills]

I'm loading by weight, not volume. But loading by MV would probably be the best, IMO.

100% agree. But don't say it so loud. I am just as happy anyone I compete against think anything else.

[Winger Ed.]

Sort of like measuring wet or dry dirt:

Relative levels of humidity in the powder can change the weight to volume measurements.

[Chill Wills]

Only if you leave the lids off your powder cans. And that is a maybe.
I've put that myth to bed with my own testing for it. Your millage may vary.

[jednorris]

I have found one change changes other things. The weighed 79 grains of the new batch left the powder column level lower in the case. As a result my bullets were no longer compressed. To bring my powder column back up to where it was I had to go to 82 grains and that brought back my C.O.A.L. It is nice having a forum like this for fools like me to get good answers.

[greenjoytj]

Remember the old joke: “What weighs more, a pound of feathers or a pound of coal”.
Black Powder density changes with the quality of the ingredients, the skill a whim of the manufacturers. Weigh your powder charge.
Even your volumetric dispenser was originally calibrated against a known mass weight of propellant fuel. Volume dispensing is just a tool to quickly dispense an amount of fuel that will weigh quite close plus or minus to the weight it was calibrated too.
The powder represents energy in solid form and the amount of energy it can release relates directly to the mass density of the powder which equates to its weight and certainly not to the degree of compression placed on it in a cartridge case.

[indian joe]

Remember the old joke: “What weighs more, a pound of feathers or a pound of coal”.
Black Powder density changes with the quality of the ingredients, the skill a whim of the manufacturers. Weight your powder charge.
Even your volumetric dispenser was originally calibrated against a known mass weight of propellant fuel. Volume dispensing is just a tool to quickly dispense an amount of fuel that will weigh quite close plus or minus to the weight it was calibrated too.
The powder represents energy in solid form and the amount of energy it can release relates directly to the mass density of the powder which equates to its weight and certainly not to the degree of compression placed on it in a cartridge case.

Yep I will back that 100% Even chrono tested it
36 grains of corned powder in a 44/40 gave me close to identical velocity to 36 grains of screened from the same raw materials. It took some ingenuity to get the screened in the case as it is only about 65 % the density of corned.
Was not setting out to prove a point at the time just curious and definitely surprised at the result.

[Old-Win]

Volume and compression is more important than weight with Black Powder.

It seems as though the Sharps rifle company expressed that compression was the most important function of an accurate load. This is from one of their brochures in the mid-1870s. "Two things that are of vital importance to be observed are, first that every shell should be filled with powder to exactly the same height and if the pouring through the tube does not carry it to the right point, a gentle tapping on the sides of the shell with another shell may do it. If not, reject that shell. Different batches of powder of same brand often very so that it is found impossible to get 100 grams in such a case, use one to three grains less as it may be found necessary taking care not to crush the powder. The second vital point is to see that the paper patch does not get torn while seating the bullet in the shell and when inserting the cartridge in the rifle be careful and not catch the patch on the rifling. Observe before inserting that bullet has not gotten loose in the shell. If it has moved away from the powder, it will fall short of the mark". The Sharps rifle company went on to express that a hot powder was not necessary but the best 1F powders from Laughlin and Rand and the Oriental Powder Company we're all that could be desired.
I've stuck with this for most of my BPCR days and it seems to work quite well. I find my overall length and then fill the case to that point and use minimal compression (.050-.070") This is using Swiss powder with GG bullets and not paper patch .

[tmanbuckhunter]

I've had very experienced BPCR shooters tell me they've seen powder column/volume vary from lot to lot as far as up or down, and weight. With that being said, I just prefer to go ahead and drop a grain or two and re-work the load. I'm shooting for score, not fun. Don't want to leave any stone un-turned.

[rjmelehan]

Remember the old joke: “What weighs more, a pound of feathers or a pound of coal”.
Black Powder density changes with the quality of the ingredients, the skill a whim of the manufacturers. Weigh your powder charge.
Even your volumetric dispenser was originally calibrated against a known mass weight of propellant fuel. Volume dispensing is just a tool to quickly dispense an amount of fuel that will weigh quite close plus or minus to the weight it was calibrated too.
The powder represents energy in solid form and the amount of energy it can release relates directly to the mass density of the powder which equates to its weight and certainly not to the degree of compression placed on it in a cartridge case.

Very interesting, THANKS.

However I have to wonder if there is not an element or two, other than powder weight, which affect accuracy.
Not the least of which would be flame propagation, burn rate and the displacement of powder, prior to ignition, from the primer.
IIRC Harold Vaughn in a book, Rifle Accuracy Facts, talked about when / where pressure spikes occur and their effect on bullet upset.
I'll dig it up during daylight hours and forward more info.

One more thought on the subject.
Because the common goal is always accuracy I'll add the results of an experiment I did a long time ago.
Again from memory...
45-70, Swiss 1 1/2, 510 grain projectile (will post rest of info later)
Same day (morning), same rifle rest, scope, charge, compression, primer, seating depth, etc.
The only variable was neck tension due to full length case case sizing vs. no sizing.
The 20 shot string with the full length resized cases at 100 yards was 1"
The group without neck tension were twice or more than that.

[GregLaROCHE]

Since I’ve gotten into BP, I’ve gotten an impression that the quantity, volume or weight, has a lot less effect on ballistics than with smokeless powders. Therefore, the way it is measured is less important, as long as the same method is always used. Do others agree or disagree?

[country gent]

Black Powder produces less velocity per grain weight of powder Than smokeless or most subs. Hence the reason for the big cases. Most of the original rounds were in the 1200-1250 fps range and performance was increased thru increased bullet weigh, Though there were "express" rounds that used a lighter bullet and increased velocity.

Loading these rounds its easy to get under 10 - 12 fps extreme spreads, with proper compression and charge weight. It is interesting chronographing test loads, as charge weight and compression goes up Standard deviation and extreme spreads go down.

[Chill Wills]

I subscribe to the "there are many right ways to do it" principal.

In 2006 I shot on the NRA International Long Range Creedmoor team that went to the championships in South Africa. Because we had to fly there and we could not bring BP on the plane, we were provided Swiss BP when we arrived. That meant starting an accurate load with an unknown lot of powder from scratch.

There were 12 of us, the best BPCR Creedmoor rifleman the NRA team trial could produce.
We all lived and roomed in a in a bed and breakfast and got to see each other load ammo from scratch. There were as many variations of how to do it as there were team members.

Be careful thinking there is only one true way and everything else is wrong.

For what it is worth, most everyone I can remember weighed powder to the 1/10th. Beyond that, there were lots of different loading methods.
Michael Rix - off to cast some bullets.

[martinibelgian]

Yup, the 2006 world championships in SA. Those were the days...