A friend kindly sent me a brand new Harrell powder measure.

And as I was going to load ammo for our safari next month, I thought I will keep track of what it actually drops by each stroke.

The hopper was filled with H4350 powder, and set to drop 85 grains per charge.

I dropped 10 charges, and discarded them, to settle the powder.

I then filled 60 cases from the powder measure.

This is roughly 2/3 of the capacity of the powder hopper.

I weighed each charge, and here is the results.

84.4 1
84.5 0
84.6 4
84.7 3
84.8 5
84.9 7
85.0 12
85.1 9
85.2 7
85.3 3
85.4 4
85.5 2
85.6 1
85.7 2

Over the years, I've accumulated 7 powder measures and, except for a Dillon mounted on my XL650 press and devoted to handgun volume reloading, the Harrell's is the only one I use for precision rifle loads. With granulated powder, it stays close to the desired charge, as you experimented yourself, and meters with (near) perfect repeatability with ball powder.

Saeed
Are those the first ten rounds, or ten rounds taken at random through the 60? If the first ten, I can understand the 1.3 grain range of charges until the powder settles down. If this is a random selection, I think it could be differences in the throwing style of the user.

I use an RCBS powder measure with the "tented" piece in the powder column to help equalize weight of the charge. I usually get less than one grain variation.

My most accurate is using the electronic RCBS scale/powder measure.
Max

quote:

Originally posted by Saeed:
A friend kindly sent me a brand new Harrell powder measure.

And as I was going to load ammo for our safari next month, I thought I will keep track of what it actually drops by each stroke.

The hopper was filled with H4350 powder, and set to drop 85 grains per charge.

I dropped 10 charges, and discarded them, to settle the powder.

I then filled 60 cases from the powder measure.

This is roughly 2/3 of the capacity of the powder hopper.

I weighed each charge, and here is the results.

84.4 1
84.5 0
84.6 4
84.7 3
84.8 5
84.9 7
85.0 12
85.1 9
85.2 7
85.3 3
85.4 4
85.5 2
85.6 1
85.7 2

Saeed, I'm baffled as to the last number in your example.
Is that the number that it was dumped, or something else completely?

I use a Redding 3BR with a baffle, it actually gives me very very good linear throws if I use the handle the same, it is accurate to +/- .1gr with powders like H1000 Retumbo and Reloader powders. Those that are long, like IMR powders give erratic dumps.

Cheers.

Cheers.

Guys, Saeed said he loaded 60 rounds. The last number is the number of rounds that had that weight measure. There were 12 rounds that measured exactly 85.0 grains.

If I were to say the two lightest throws were an anomaly( well 84.5 actually had no loadings), even a full grain dispersal is horrid, in my way of thinking. If a Harrell can't hold a full grain tolerance, get rid of it. Not even half measured within +/- .1 grains in either direction.

Nice, now if you can get Walter to agree to never "fix" it. You'll do well.

That is good with a stick powder I find most measures will throw ball powder very accurately.

I must be lucky. Even my old Lyman 55 goes better than 1 full grain round to round variance.

quote:

Originally posted by 416RigbyHunter:
I use a Redding 3BR with a baffle, it actually gives me very very good linear throws if I use the handle the same, it is accurate to +/- .1gr with powders like H1000 Retumbo and Reloader powders. Those that are long, like IMR powders give erratic dumps.

I also use a Redding. I guess that I just didn't realize how good it is. I've run H4350 through it and never gotten a variation more than about + or - .3 grains or so. However, consistent operator manipulation contributes a great deal to its accuracy.

I'm surprised that the Harrell, with its reputation and price, didn't do better.

On really coarse stick powders the Redding will vary as much as .6 or .7 grains. With these powders I set it a half-grain low, dump into the powder pan, then trickle up to the desired weight. Every now and then the dump will be overweight, so I just pour it back and dump again. Similarly, about a third of the dumps are close enough (<.1 grain off) that I use them as is.

The Redding is essentially dead on with every dump with ball powders.

quote:

Originally posted by prof242:
Saeed
Are those the first ten rounds, or ten rounds taken at random through the 60? If the first ten, I can understand the 1.3 grain range of charges until the powder settles down. If this is a random selection, I think it could be differences in the throwing style of the user.

I use an RCBS powder measure with the "tented" piece in the powder column to help equalize weight of the charge. I usually get less than one grain variation.

My most accurate is using the electronic RCBS scale/powder measure.
Max

I did not use the first ten charges dropped.

I thought I would do that to settle the powder in the hopper.

The numbers after the charge is the number of charges dropped in that weight.

Depending on the charge I am looking for, I do allow a bit of a leeway in what is loaded.

In this case, I use loads that are 85.0 to 85.2 grains.

Sop taking the above charges, 28 out of the 60 measured were used straight out of teh powder drop.

The other 32 were adjusted either down or up.

I have tried a number of powder measures. Most will drop ball powder very accurately, and some of the other powders that use very small granules.

Powders with large granules are terrible with powder drops - in fact, I never use a powder drop for them at all.

I used to use a Redding BR powder drop, which gave similar performance to this one.

But, for larger cases, I had to adjust it for two drops per charge.

This one has a much larger capacity, which makes it a bit easier to use by using just one drop, and weighed.

Saeed,
Forgive my lack-of-sleep reply as to the order of throwing. As noted by others and myself, a baffle can help narrow the spread of the charges. I don't know if they make one for the Harrell or not. Walter may be able to make one (or you may want to totally ignore this sentence).

1.3 grn ES is not so unusual for any measure given extruded powders. Adding a baffle usually helps. Technique is critical too- do the same thing every time- rap twice, slow smooth lever up, same down, rap twice, repeat. Keep hopper 75% or better filled.

Surprisingly, after several high dollar measures, I still use my Lee Perfect most of the time-it really does the job. Example- I load IMR 4064 in my NM M1 Garand, 47.4 plus/minus .2 is my sweet spot- for 600 yds plus I weigh and trickle every charge, my last batch of 200 loads I had maybe a dozen that were less than 47.2 or greater than 47.6. Test batch of 20 showed an ES of 18 and an SD of 7.8.... Good enough for the X ring at 1000 if I can see the bull and the wind!

Another $26.00 well spent.

Added a vibrator to mine, will throw a consistent charge of pretty much any powder without headache.

If he were a very, very, very, good friend he might send you one of Neil Jones measures. From testing over the years this is the one I would buy with my own money.
www.neiljonesproducts.com

I have, in the last three or four years, begun to set my Jones measure to drop just under half of any charge over about sixty grains. Drop two half charges into the pan of my AccuLab (made bu Sartorius) VIC 123 electronic scale and trickle up.

Glad I went with the Redding 10X for handgun and the 3BR. The 10X never varies more than 1/10th of a grain with any handgun powder I ever used.

The old antique looking slow Belding& Mull is the most accurate of them all with any type powder.

There is no volume powder measure that can give you exactly the same volume/weight every time. The Harrel is one of the best since it is running on roller bearings. The only way to minimize difference from one throw to the other is to keep the upward stroke stroke equal in term how hard you "hit" it to the top when it is suppose to collect the powder in the measuring cylinder. That is why we use a tickler to fine tune exact loads.

I have a Lyman 55, a Belding and Mull, a redding, and atop my Lyman turret press sits a cheesey old Lee perfect PM. My other PM's have pretty much been relegated to the dust bin. Quite a bit of testing has found it to be the most accurate and trouble free of them all. I got the press mount adapter off of flea-bay for some outrageous fee like $10.00. Every time I seat a bullet after charging a case the action of the press gives the PM a very uniform little jostle. It is still probably not as good as the harrels with stick powder, but pretty close. I have been considering a quantum leap to an RCBS chargemaster. Does anyone have some accuracy testing results from their Charge masters? I have to say, those results from Saeed's Harrels looks pretty impressive.

Does a grain of powder make a difference ?

Depends. Is it one grain with my 135gr loads for my 550 Gibbs, or one grain with my 14gr loads for my 22 Hornet?

Ok lets make it percentage.
What percentage of load mass does it take to change pressure and velocity ?

quote:

Originally posted by ALF:
Ok lets make it percentage.
What percentage of load mass does it take to change pressure and velocity ?

It seems to me that the closer you get to max, the easier it is to get a pressure spike. Especially with smaller volume cases.

I just set the measure, a old RCBS, to drop just below the weight I want and trickle in the rest; then they are all the same.

When it comes to hunting loads I see no reason to be in a hurry.
shane

quote:

Originally posted by npd345:
I just set the measure, a old RCBS, to drop just below the weight I want and trickle in the rest; then they are all the same.

When it comes to hunting loads I see no reason to be in a hurry.
shane

The preferred method, actually doesn't take that much time once you're set up.

Grizz

Saeed,

What scale did you use to measure the weights of the throws?

I ask because I weigh all my thrown charges and have read elsewhere that the Lyman M5 scale is the best (beam) scale for linearity and accuracy. (I prefer beam over electronic scales.)

quote:

Originally posted by B L O'Connor:
Saeed,

What scale did you use to measure the weights of the throws?

I ask because I weigh all my thrown charges and have read elsewhere that the Lyman M5 scale is the best (beam) scale for linearity and accuracy. (I prefer beam over electronic scales.)

I use an RCBS Chargemaster 1500 digital scale.

I have stopped using balance beams years ago.

The balance beam scale (an accurate one) is a necessity for insuring the integrity of an electronic scale and a measure, imho. The Lyman is the best according to the long range guys. BR guys usually don't know exactly what their load is.

The only way I would be without one were if I were only interested in hunting loads, not increasing accuracy or pressure much over factory.

This thread speaks to the differences between volumetric loading vs individual charge mass measured loading.

There is no doubt that volumetric loading is less precise than individually weighed loads for obvious reasons.

The question is then are micro weighed loads more or less accurate than simple weighed loads ? ( perhaps a dumb question because they have to be ? however the limitation is individual powder kernel weight )

A better way of putting the question would be: Is it therefore useful to load using a pharmaceutical balance capable of measuring micrograms as opposed to a run of the mill loading beam scale or electronic charger ?

Our gun system relies on gas laws to function and though the absolute charge mass is obviously important there are other factors more, less or equal in importance.

Small variations is charge mass often get lost in the whole internal ballistics cycle.

If we look at howitzers for instance charges are volumetrically loaded and yet they are capable of what can be called as precise shooting albeit at very long ranges.

quote:

Originally posted by npd345:
I just set the measure, a old RCBS, to drop just below the weight I want and trickle in the rest; then they are all the same.

When it comes to hunting loads I see no reason to be in a hurry.
shane

I dont mind scaling every charge, but I really dont like trickling. Anymore I would rather just toss anything more than 0.4 gns +/- back into the hopper and just throw another charge. And 9 times out of 10 they fall within those parameters. Unless I'm doing everything I can to try to get a rifle to shoot, that's close enough for me.

This thread got me thinking about the internal workings of powder measures. As I mentioned before, one of mine is a VERY old Redding. I believe Atkinson and Bartsche also use the same one, mine was among my least accurate PM's. So I tore it down and found a lot of rough machine work on the drum and the housing. So out comes the 250 grit emery paper.. And by George I think it worked! It is definitely smoother to operate now and after loading up a couple boxes of 308 with it I was getting much improved accuracy (from the PM).. Just thought I'd mention that in case anyone wants to try improving their current PM. Just polish that drum and housing up as slick as you can and who knows, you might not need that old trickler anymore.. Just be careful to not take off too much meat and cause yourself a leak.

quote:

Originally posted by ALF:
This thread speaks to the differences between volumetric loading vs individual charge mass measured loading.

There is no doubt that volumetric loading is less precise than individually weighed loads for obvious reasons.

The question is then are micro weighed loads more or less accurate than simple weighed loads ? ( perhaps a dumb question because they have to be ? however the limitation is individual powder kernel weight )

A better way of putting the question would be: Is it therefore useful to load using a pharmaceutical balance capable of measuring micrograms as opposed to a run of the mill loading beam scale or electronic charger ?

Our gun system relies on gas laws to function and though the absolute charge mass is obviously important there are other factors more, less or equal in importance.

Small variations is charge mass often get lost in the whole internal ballistics cycle.

If we look at howitzers for instance charges are volumetrically loaded and yet they are capable of what can be called as precise shooting albeit at very long ranges.

ALF,

I am afraid I cannot answer your question.

But, taking into consideration that we try our best to avoid any variations between our loads, I SUSPECT that weighed charges MIGHT be more accurate.

It does take more time to weigh all charges, but I enjoy it, especially for my hunging loads.

I think in one of the past SPEER loading manuals it was mentioned that 0.2 of a grain made no difference at all.

I have also experienced a rather disturbing thing happen sometimes with very large cases like the 460 Weatherby Magnum.

An increase of a 2 grains actually give me a LOWER velocity!

quote:

Originally posted by Saeed:

I think in one of the past SPEER loading manuals it was mentioned that 0.2 of a grain made no difference at all.

And Ill bet that the truth in that assertion varies from one rifle to another as much as accuracy does. Meaning that in some cases even more variation would also make no difference.

ALF,

the Holy Grail is to have no shots taken that go astray due to equipment tolerances. Only shooter error.

I would be on pretty safe ground to say that if you do not:

segregate your brass by lot numbers, neck thickness, and weight.
segregate your bullets by lot number, weight, and BBtO* length, a couple of kernels even a couple of 10ths, even a grain or two will not matter.

As an example: the five years I shot Hunter Class Bench Rest, it was with a tight neck FL 308 Winchester. The closest range was LaGrande, OR, about a two hour drive. Each December (early), two of the guys I shot with there and I would buy 10,000 Sierra 150gr Match Kings. They drove over with their wives, and the ladies went Christmas shopping. We sat at my kitchen table and each had a gauging tool, that looked like a six-sided 1" or so thick hex nut, that fit on a dial caliper. It had slots that fit the jaws, and six different sized holes for the BR calibers.

Sierra used three point up dies to create the final nose shape. At that time, they dumped output from all three into one hopper, boxed and sold them. We would zero our gauges, and then start the process of sorting them into three boxes, based on the base to ogive variation. The shortest of the three would be where we "zeroed" the calipers. The two other bullets would be .006" and .009" longer. Setting ogive to origin of rifling is critical to accuracy. The idea behind sorting in this manner, was that most shooters would adjust the amount of "Jump" that the bullet made before the ogive contacted the origin of rifling. I settled on .010", ten-thousandths off of the origin with the shortest of the three bullet lengths. If I got a +.009 and seated it, I would be just a thousandth off the rifling and pressure would be much higher than one of the shorties. If the gentleman who took the +.009" got a shortie, he was nearly doubling his jump. If I "jammed", set the ogive into the rifling say .010" with mine and got a +.009 I would be nearly .020" into the rifling, and pressure would be way higher.

The basic idea is to eliminate or minimize the variables you can control, and learn to dope the wind.

hope this helps,

Rich


*Bullet Base to Ogive

The decrease is velocity when powder mass is increased is a well known ballistics phenomenon.
It does not mean though that pressure has decreased !

This comes from the fact that during the ballistics cycle that not only does the bullet accelerate but the generated gas mass behind it has to be accelerated as well.

If the charge mass gets to big relative to bullet mass and the gas mass gets to big then increase in bullet velocity actually decreases and reverses. Theoretically we see that a bullet can actually have zero velocity if the gas mass gets to much. There is a velocity limit to every gun !

It is a law of diminishing returns.
it actually has a doubling effect,


The Charge weight to bullet weight ratio plotted against velocity shows this. The more powder is added for a given bullet weight shows a exponentially rising curve which reverses at a point . This point is the velocity limit of the gun.

quote:

Originally posted by ALF:
Theoretically we see that a bullet can actually have zero velocity if the gas mass gets to much.

And we all know what happens then!

quote:

Originally posted by ALF:


If the charge mass gets to big relative to bullet mass and the gas mass gets to big then increase in bullet velocity actually decreases and reverses.

Wow.. That is bizarre! Are you saying, in other words, that there is a point where the pressure overcomes the drag on the projectile so rapidly that the bullet suddenly accelerates beyond the "wake" of effective pressure before it exits the bbl? Or am I misunderstanding this?

quote:

Originally posted by Wstrnhuntr:

quote:

Originally posted by ALF:


If the charge mass gets to big relative to bullet mass and the gas mass gets to big then increase in bullet velocity actually decreases and reverses.

Are you saying, in other words, that there is a point where the pressure overcomes the drag on the projectile so rapidly that the bullet suddenly accelerates beyond the "wake" of effective pressure before it exits the bbl?

That's my understanding. If you think of 3 inches of lead in your barrel as a "projectile" then a cartridge sans conventional bullet fired would not cause it to move . . . but might cause other things to . . . er . . . move . . .

it is not so bizarre when we consider what exactly goes down during the ballistics cycle.

Most of the solid propellant is converted to gas during burn with a small residual solid component (by products of combustion) This gas however can be described as having sectional density because it has mass and occupies initially the same volume is the powder charge.

The greater the initial charge mass the greater the gas mass produced and the larger the SD of the gas.

We know from physics it takes more energy to accelerate a high SD body than a low SD body.

If we consider how energy is lost or utilized in the system we see that only a small portion of the total energy ends up as bullet kinetic energy. We can call this work. The energy contained in the charge mass is used up (work done) to overcome engraving resistance, lost as heat , used in the recoil of the gun parts and then very important a large portion is used to accelerate the gas mass down the bore.

If the gas mass is to large all the energy is "consumed" to accelerate the gas and little is left for the bullet.

An example of this can be found in large bore guns where propellant charges are added for distance. The M109 155mm Howitzer as example.
Charge mass is added to achieve certain start velocities for certain ranges. The increase in velocity is not linear to the added charges, there is situation of diminishing return. To double velocity you have to add 4 times the charge mass and so forth.

quote:

Originally posted by Saeed:
A better way of putting the question would be: Is it therefore useful to load using a pharmaceutical balance capable of measuring micrograms as opposed to a run of the mill loading beam scale or electronic charger ?

Not really.

I also have a Harrell and an RCBS thrower scale combo thing. But I use a teaspoon, a Tanita jeweler's scale (+/- 0.05 gr) and a pair of tweezers. The 0.05 gr is more or less 1 kernel of long (IMR 4831) to 2 kernels of short H4831 SC) tubular powder.

The RCBS does indeed dispense +/- 0.1 as advertised. So even though more precise, the Tanita would still only be +/- 2 kernels from the target measurement at either extreme (e.g. 53.95 gr -1 <- 54.0 -> 54.05 gr. +1) The RCBS would be +/- 4 kernels (eg 53.9 gr -2 <- 54.0 -> 54.1 gr +2 )

Does it matter- prolly not on paper between the RCBS and Tanita.

But it does satisfy the 90% between the ears.

Yeah I also spine align and FLO all my golf club shafts as well.