3F-2F difference

[George]

In another thread Roundball pointed out that if you change the size of shot in a shotgun load but keep the volume the same you will make a change in the weight of shot used. Since small shot has less air in a volume it weighs heavier, so if you go to a smaller size you will increase the weight of the charge, but if you go to a larger shot you will decrease the weight. If you keep the powder charge the same, the smaller shot will lose velocity, and that means less energy on two accounts, because smaller pellets have less energy and because slower pellets have less energy. By the same reasoning, going to larger shot will increase the velocity because it weighs less, and that will increase energy in two ways, because of increased velocity and because larger pellets have more energy.

Head hurt yet?

I got a new digital scales and am having fun measuring everything. Sorted out twenty .600-inch "hunting" balls for the Carolina smoothbore with a 0.3 gr. tolerance, for instance. Then I checked the "80 grain" antler tip powder measure I use all the time for that gun and found it actually throws 90 grains of 3F. So I corrected it, but since I've been happy with it as it was, I only reduced the charge to 85 grains. Fiddling with that, I was thinking about Roundball's info about changing weight when you change shot size, and it seemed logical the same would be true of powder. After all, the change is due to nothing but change in physical size of granules, so it should hold if you change powder, say between 3F and 2F. I filled my antler measure with 3F five times, measuring as accurately as I could, weighed them and got an average of 83.6 grains. Did the same with FFg and got an average of 78.6 grains. Just as expected, increasing granule size reduced the weight of a set volume of powder, decreasing granule size increased the weight. And, just as with pellet energy, we get a double whammy. If you go from FFg to FFFg you get more power because of two factors, there is more powder by weight and powder with smaller granules burns faster with more pressure.

Ballpark figures, Roundball's changing from #6 to #7 shot made a difference of about 11% up or down, my change from 3F to 2F powder made only a 6% difference. Maybe the difference in granular shape makes the difference, spheres for shot, irregular for powder granules so that they fit together differently.

Now my head hurts. But in a good way.

Spence

 

[BrownBear]

In my mis-spent youth we were trying to reach some really high flying doves late in the season and decided to build some 3" #8's for our 12 gauges using the 1 7/8 oz bar on our shotshell loader.

Those things did the job, but man, did they ever kick since we were shooting almost straight overhead. A couple of seasons later someone in our ratpack got a loading scale out and weighed the shot that bar was dropping. Turns out we were loading 2 1/8 oz of #8's. :shocked2:

 

[necchi]

Good for you,ya figured it out..

Now,,Keep In Mind, Black Powder And the Replicants are measured by Volume not Weight.

You have made the corralation between volume and weight and noticed the differance.

YOU as an individual can measure your powder any way you want, as long as you do it that way all the time! You can set your volume measure to cast whatever weighed charge you want, as long as you use that same volume.

Trouble comes when you decide you want a 100grn charge by volume,,weigh 100grns and set a measrue to that,,it'll actually be closer too 115-120 grns by volume!! :nono:

BP in ML's is much more tolerant of small variations than modern nitro powders, Where as modern powder charges can show dramatic changes in 2 tenths of a grain, an accurate load of BP may be tolerant of +/- 2 full grains. Digital weight of a BP charge isn't critical.

 

[George]

Now, Keep In Mind, Black Powder And the Replicants are measured by Volume not Weight.

Sure, but there's a correlation between the two. That volume... volume of what?

Trouble comes when you decide you want a 100grn charge by volume,,weigh 100grns and set a measrue to that,,it'll actually be closer too 115-120 grns by volume!!

You dazzled me with your footwork on that one. I may be about to learn something. Since the unit "grains" has always been a weight measurement, not a volume measurement, in both troy and avoirdupois systems, where are you saying the volume we use comes from? What's the relationship between weight and volume as we use them? How do they figure out where to put the marks on my adjustable measures?

Where as modern powder charges can show dramatic changes in 2 tenths of a grain, an accurate load of BP may be tolerant of +/- 2 full grains. Digital weight of a BP charge isn't critical.

At least that much. I've always found that as a hunter I can't tell the difference between charges as much as 5 grains different.

Spence

 

[necchi]

I know, it's a tuff one to grasp.
The volume measurement came about along time ago when powder was brought over in casks on boats, and its measured to what we call a "2F equivlant" today.
And your right, the markings on volume measures nowadays seem almost random, different makers measures won't equaly compare to anothers.
It's much like beam and electronic powder scales today, one scale may well be off .1-.2 from the other even in the same guys house, it causes much quandry to the individual when he wants to exactly replicate a "Book" load. Which scale should he trust?

Bottom line, is a guy needs to use a measure that is repetable. Something that will be the same each time, whether that's a scale or volume matters not.
I guess I've chosen to simplify and use an adjustable volume measure while finding a load, then transfer that volume to a fixed measure.
(I have 3 adjustable volume measures, all 3 will toss a different scale weight when set to a "70" marking, I have 1 I trust for load development and leave my beam scale on the CF loading bench where it belongs) :grin:,when running shot loads I check it on the scale. Shot's not powder.

Maybe someone else will come along and explain better why the weight is different than volume,, with all respect intended trust me, when you read here about someones 90grn load of 3f, he's probably useing a volume measure an ya might be a little bit off if you try weigh 90grns on a scale and use that load.

 

[Dphar]

For precision charges powder must be weighed. It impossible to load consistently, by the standards of the slug gun shooters and other serious competitors, without this process. But some matches require loading from a pouch and horn and this means volume.

However, even when loading BPCR for serious long range use it is necessary to find the volume needed to properly load the case with the projectile being used then WEIGH that charge. Having a weight (and consistent powder) allows repeating the load with less hair pulling.

But I shoot MLs by volume all the time. If done carefully its possible to load consistent enough for most uses with a horn and volume measure.

Dan

PS
Swiss is very close to volume and weight.IE 70 grains volume will usually be close to 70 by weight. But its pressed to a higher density.

 

[George]

I know, it's a tuff one to grasp.
The volume measurement came about along time ago when powder was brought over in casks on boats, and its measured to what we call a "2F equivlant" today.

Told you I was going to learn something, I never heard of that. Where can I find some reading about that 2F equivalent? Do you think manufacturers of powder measures use that today?

Bottom line, is a guy needs to use a measure that is repetable. Something that will be the same each time, whether that's a scale or volume matters not.

For accuracy, you are exactly right, but there are other things to consider. It can be perfectly repeatable and still way wrong, even dangerously so.

I guess I've chosen to simplify and use an adjustable volume measure while finding a load, then transfer that volume to a fixed measure.

Exactly the way I do it. Problem is, it is apparent my adjustable measure is off the mark by a significant amount, like 20%. I used it to measure for my fixed measures, just checked all of the fixed measures and they are high, every one.

(I have 3 adjustable volume measures, all 3 will toss a different scale weight when set to a "70" marking, I have 1 I trust for load development and leave my beam scale on the CF loading bench where it belongs)

I have 4 different adjustable measures I've accumulated over the years, and I just checked each of them set on 50 grains. They dropped 63, 53, 49.8 and 56.3 grains. Now, it seems reasonable to me that the manufacturers of those middle two were trying to make their measures actually drop the amount the are marked for, in grains. I'd guess the other two do so poorly simply from poor design and manufacture. I think what they do, or were trying to do, is weigh out the various charges in grains and mark on their measures the volumes matching the weights. Otherwise there would be a complete disconnect between weight and volume, and I don't think that's the case.

In your earlier note you said:

Trouble comes when you decide you want a 100grn charge by volume,,weigh 100grns and set a measrue to that,,it'll actually be closer too 115-120 grns by volume!!

You are going to have to explain to me the difference between 100 gr. by weight and 100 grains by volume. You seem to be using volume as though it is a weight scale, separate and disconnected from all other measurements., and it isn't, so far as I know. Volume isn't measured in grains. There is a volume which is occupied by X number of grains of powder, but it is a fixed relationship, 1 x 1, not 1.2 x 1 or any other. When I say measure out 50 grains by volume, I mean measure out the volume of BP occupied by 50 grains by weight. If you do that, you will have 50 grains by weight. Any other result means somebody screwed the pooch when making your measure.

In my case I used and have always used volume measurements in loading BP. I've never weighed a BP charge before today, not since 1973. That is what created the problem I have, because in every case the volume measurement was high, not the weighed measure. Because my adjustable measure, which measures by volume, is wrong on the high side, every load I've ever thrown with it, every fixed measure I've made using it and every charge dropped by all of those was higher than I thought and wanted. If safety were an issue, I would have been better served to weigh all my charges, because every one of my adjustable measures lied to me on the low side.

with all respect intended trust me, when you read here about someones 90grn load of 3f, he's probably useing a volume measure an ya might be a little bit off if you try weigh 90grns on a scale and use that load.

I'm sure you are right, because that's the way we all do it. I'd guess, though, that if you weighed the 90-grain load he measured by volume you'd find he is actually shooting 110 grains actual weight, not the 90 grains his measure showed. How can it be safe to always shoot more powder than you think you are? If my adjustable measures are typical, that's what is happening. Makes the concept of a safe load a bit of a guessing game, doesn't it?

One good, very good thing about all this is that the safety margin built into BP prevents problems within this range of errors. That's why manufacturers can sell us lousy measures without getting themselves or us in trouble. That's why I'll continue loading as I always have. I have no plans to start weighting my charges, no reason to quit a winning strategy.

Of course, all this nonsense with the non-standard measures means that we can't exchange useful information about loads. You don't know what you are shooting any more than I do, why bother sharing? Same thing goes for shot as for powder, of course, since we use the same wonderful volume measures for both.

Man could make a mint selling accurate volume measures.

Spence

 

[BrownBear]

If I'm using the same measure to develop a load and thereafter to load and shoot the same gun, the scale on the thing means diddly. If I read about some wonderful load someone else has found, same answer. The odds of it being wonderful in my particular gun aren't as high as those of finding two graduated measures that weigh the same.

I'm with Dan. If you feel the need for absolute precision in measuring out a load, break out a scale. And carry it with you in the field! :rotf:

 

[necchi]

I'm not going to be rude enough to disect and rebutt each of your sentences beyond just these two,

In my case I used and have always used volume measurements in loading BP. I've never weighed a BP charge before today, not since 1973.

there was another part that went like,,

every fixed measure I've made using it and every charge dropped by all of those was higher than I thought and wanted

Here's the part I don't understand about the entire thread, you mean to tell me for all these years you haven't been able to find a load that suited your need, that every charge you've fired has been inept, and low of powder for your needs until this very day that you've weighed a charge?

Now suddenly versed with the reality of a weighed charge all of your shooting and loads are now in question?

I've only been shooting ml since 85, it took me actually about 3 weeks to weigh a charge and recognize the differance,.

I wish you luck friend. And good day to you.

 

[George]

Here's the part I don't understand about the entire thread, you mean to tell me for all these years you haven't been able to find a load that suited your need, that every charge you've fired has been inept, and low of powder for your needs until this very day that you've weighed a charge?

If that's what you got from my comments then I did a poor job of expressing myself. I have never had any trouble finding a load which suited my needs, and have done it using volume measurements exclusively. And I've always been aware that the markings on my adjustable measures were approximations, but I assumed close ones. Weighing a few charges showed me that was an unwarranted assumption.

As I said above, I have no plans to change my way of doing things. Volume measurements have always done the job for me and will continue to do so, because my end point is the way the guns shoot, not some mark on a measure. Or a scale. BP will let you do that.

I'd still like to have that reference to the history of the volume measurement method and the "2F equivalent" if you run across it.

Spence

 

[George]

If I'm using the same measure to develop a load and thereafter to load and shoot the same gun, the scale on the thing means diddly.

Under ordinary circumstances I'd agree 100% with that, and it's the way I usually do it. There are some situations, though, where it might make a difference.

I shoot a couple of original, light weight SxS with damascus barrels, and I limit my loads pretty severely in them. I always thought I was loading 50 grains, but turns out I was loading 63.

I once worked up a heavy load for a double .54 rifle with a manufacturer's recommendation of 130 grains of FFg. I always shoot FFFg in my .54s so I worked up to 110 grains, the equivalent load to 130 grains FFg. I was actually shooting 134.7 grains of FFFg, a charge I would have never done on purpose.

Such a discrepancy between what a measure indicates and what it actually drops could be an unsafe thing.

Spence

 

[necchi]

George
Well your right and I’m wrong,
Historically, powder was sold by the Dram and Pound with NO mention of any volume being related to 2F or anything for that matter.
We all know powder was measured by volume of some sort for each shooter for his gun. Even the olde matchlock the shooter carried a bandoleer of the “12 Apostles”.
Mention of “enough to cover the ball held in the palm” and guns being sold with a measure made buy the gunsmith is part of history.

Bill Knight,aka; the Mad Monk explains the size of our current powder here;( log in and read the mutterings of the mad monk, a must for every BP shooter) http://www.laflinandrand.com/
A section of Part 6 says;

Screening.
The grain sizing system in use in the United States today was first introduced around
1836 as a means of standardizing grain sizing within the industry. These sizes were not
universally accepted or adhered to until very late in the 19th century.
Under this standard sizing:
Must pass through Must be retained on
Fg 14 mesh 16 mesh
FFg 16 mesh 24 mesh
FFFg 24 mesh 46 mesh
FFFFg 46 mesh 60 mesh
There is something of a logic behind these screen sizes. If one looks at the opening
size in these screens and averages each set one will find a mathematical relationship.
If each screen size range is averaged to get a “mean diameter” one finds that the
mean diameter of 2F is half the mean diameter of 1F and 3F is half the mean diameter of 2F.
In other words, as one goes down in grain size the average grain size is halved.
This is a way of exercising some control of the amount of surface area per unit of
weight in a powder charge in a gun.

The issue of our current volume measures being “equivalent” to 2F is related to the replicants available since the mid 70’s, their weight and volume being so different and varied they have to compare to something as a base for shooters to use.

Eating Crow isn't too bad if it's marinated overnight and slowcooked the next day,, :redface:

 

[George]

Thanks for the info, Necchi. The bit about each added F halving the granule size is interesting, I never realized that.

Eating Crow isn't too bad if it's marinated overnight and slowcooked the next day,

I've eaten more than my share, enough that I don't mind the taste, anymore, but I still hate getting the feathers stuck in my teeth. :grin:

Spence

 

[squirrellluck]

Now fill you powder measure(volume) with the aid of a drop tube and then weigh it and compare to your original weight from the same measure




:wink:

 

[George]

Now fill you powder measure(volume) with the aid of a drop tube and then weigh it and compare to your original weight from the same measure

I've never used a drop tube, but I've read about them in BP cartridge reloading. As I understand it they pack the powder in more, so I'd expect the measure to weigh out even more. In an attempt to always be consistent with my charges, I've learned to fill the measure, tap the side of it with a knuckle 3 times to settle the powder, then fill it again. Gives pretty consistent measures, maybe not maximum weights, and it's easy to do in the field.

Spence







[/quote]

 

[longbow1]

I have read some where I really don't remember the loads were made by placing the ball in your cupped hand and pouring the powder over the ball until it was covered . Then it varied by the size of the ball :idunno:

 

[hoochiepapa]

I recently read that the hand was not cupped, but flat, and that was how the early gunners measured their powder. I have found that 25 grs. of 3F is very accurate in my .32, and when I did the palm thing, it came out to 20. So that's what I've been using for small game.

 

[longbow1]

It was awhile bace it may have been flat palm

 

[longbow1]

damn my fat fingers (back)

 

[longcruise]

Of course, all this nonsense with the non-standard measures means that we can't exchange useful information about loads. You don't know what you are shooting any more than I do, why bother sharing?

Bingo!! Give that man a ceegar!

I been trying to say that on this forum forever. Maybe it's done because we like to deal in absolutes, even when they are not absolute. Or, maybe it's a carry over from modern smokeless reloading where weight is always used and IMR 4831 or whatever powder is consistently manufactured so as to be the same in each jug.

I discovered this discrepancy between adjustable measures quite a few years ago. Since then, I have settled on one and use it all the time when loading charges or when creating fixed measures.

As far as the history of measurement, etc., it is fairly irrelevant in a practical sense. Would be interesting to know how any measure manufacturer comes up with their increments, but in the end if you stick with one adjustable measure it does not matter.

Further, 70 volumetric grains of Swiss 2f or goex 2f or graf 2f or scheutzen 2f all have different weights. There is no way that a measure could be made that will address those differences.

Also, when creating fixed measures it is essential that you weigh the amount of powder thrown by the adjustable measure and then gradually bring the fixed measure down to match it. But, you must pour the powder from the same vessel or with the same fixture. Most likely your horn. Reason being, that if you pour from your adjustable measure into the fixed measure as you are making it, the fixed measure will overflow before you get to the amount (by weight) that is coming out of your horn and into the adjustable measure.

That's probably not a very good explanation, but writing is my short suit!