Measuring Flaky Powders

[McShooty]

I think a lot of the frustration in measuring flaky powders like Unique and Red Dot comes from weighing individual charges during the set-up process. The remedy is: Do not weigh individual charges. Throw ten charges into the pan and weigh the total. The average of ten charges gives a much better idea of the current measure setting and a much better idea of the adjustment necessary to get you where you want to be. It doesn't take that much time.
I wanted to make up some loads for .38 Sp. using 3.8 grains of Unique. After setting a Lee Perfect measure for this, I threw 5 sets of ten charges each and weighed them on a DS-750 digital scale. The weights were: 38.4; 38.6; 39.0; 38.4, and 38.6 grains, showing very good long-term stability of the charges for Unique in this measure. Of course, there is still load–to-load variation in the charges and this should be minimized by keeping the hopper full and the powder well-settled in it.
I then threw 20 charges in primed cases and loaded Penn 148-gr DEWCs on top. No check weighing, but all were eyeballed to make sure of a charge. At the range with my Model 14, these rounds averaged 969 fps with a spread of 54 fps and an average deviation of 13 fps. Accuracy was plenty good for plinking and informal target work.

 

[armadillo]

I also weigh several charges to get an average.

Another trick I learned - is to tap the side of the powder measure several times so the powder will "settle" before I throw any charges. If you don't, the first few will weigh less than the subsequent charges.

 

[Paul5388]

The problem with weighing 10 charges and using an average is, one charge could be 2.8 gr and the next could be 4.8 gr and it will still average out right.

Since you have a digital scale, just dump each charge in the pan to check a no-go/go range. If it's within that range, use it. If not, dump it back in and do it over.

 

[arjay]

With unique,I just dump 10 charges,throw em back in the hopper and then weigh and adjust.After that I check weigh every tenth charge.I refill the hopper at the 3/4 mark and my charges are pretty consistent.I don't use it for mouse loads nor magnum loads.That's what bullseye and 2400 are for.

 

[McShooty]

The problem with weighing 10 charges and using an average is, one charge could be 2.8 gr and the next could be 4.8 gr and it will still average out right.

Since you have a digital scale, just dump each charge in the pan to check a no-go/go range. If it's within that range, use it. If not, dump it back in and do it over.

That does not happen. If charges could vary by as much as 2 grains from dump to dump, I would never get the five uniform sets that are reported. I do this so that I can use Unique and not have to weigh every charge as you suggest. The uniformity is shown by the weights of the 10-shot sets and by the shooting results.

 

[Rule3]

The larger the sample of many totaled charges, the better the "average" will be. Which is just that, an average of the total weights.

As Paul mentioned it has nothing to do with each individual charge. One could be low, one high and one just right.

 

[Paul5388]

Obviously, the numbers I used were just examples that probably are too far apart for a real world scenario. But, Unique is not noted for metering well, so a variation of a few tenths is quite possible and still average out right. A few tenths wouldn't be detectable by a visual look in the cases.

The time involved in setting a powder measure for 20 rounds is easily beat by using dippers and a scale. Using a scale isn't in the same category as going to the dentist, since it's actually quite painless.

 

[Neumann]

The average weight of 10 charges is a good indication of the set point, possibly overkill. You would still want to record all 10 individual charges and calculate the range (high - low) or standard deviation. The latter is a better indicator of how accurately the weights will be thrown overall. At very least, you will detect serious problems (e.g., variations greater than +/- 0.2 grains).

To a first level of approximation, the net accuracy of the weighing system is equal to 2 standard deviations. Most scientific calculators, or the "calc" program that comes with Windows, will do these calculations for you.

This is very basic measurement science. I'm surprised none of the loading manuals touches on the subject.

Incidently, I get a standard deviation of about 0.1 grains dumping 6.0 grains of Unique (.45 ACP, 230 gr hardball) from an RCBS hopper with a small cylinder. After the initial setup, I check every 10 loads to detect any long-term drift.

 

[Forrest r]

Powder baffles & unique go hand in hand, they really make unique throw alot more consistently. There was a post on here that someone did that had a page that could be printed with different sized baffles for the different dia powder throw tubes along with slow & faster flow baffles for the same sized tubes.

Those baffles are sweet, they really shine when I use unique, ww231/hp-38, bullseye & clays.

 

[blujax01]

The problem with weighing 10 charges and using an average is, one charge could be 2.8 gr and the next could be 4.8 gr and it will still average out right.

...

If I were to get that wide of a range, I would suspect my gear rather than the powder.

Neumann's explanation of Standard Deviation and drift apply.

 

[Bomberman]

With unique,I just dump 10 charges,throw em back in the hopper and then weigh and adjust.After that I check weigh every tenth charge.I refill the hopper at the 3/4 mark and my charges are pretty consistent.

I do exactly the same thing but only if I'm loading more than 20 rounds at a time. Any less than that I use a dipper and weigh individual loads.

 

[Maximumbob54]

I don't see the point. I just avoid PITA powders like Unique. It makes a great mild magnum powder, but other than that I have replaced its usefulness in everything else with Win 231. I don't get the justification of staying with a finicky to measure powder when there are so many options out there that aren't nearly as difficult to get the +/- .1 grain with each load. Granted, I don't have the decades of reloading that some guys have under their belt, but someone feel free to inform me why there are so many hard corps Unique users out there???

 

[dhom]

dhom

I load Unique for medium loads as well, using a 1975 RCBS powder measure. Norrmally checking every 5 to 10 thro's and my results seem to be only about .2 tenths variation as long as I keep the amount of powder in the hopper pretty much the same.

 

[Skip Sackett]

Statistics are one thing.......Then there is loading.......

When doing statistical analysis, you are exactly right. If all of the loads ended up in one case and you were hoping for a total, that was safe, sure, measure them that way. Have fun.

The problem is, each charge goes into it's OWN case and Paul's scenario just isn't that far fetched, especially with hard to meter powder.

Unique can be a pain to deal with, others too, BUT, weighing many charges together is, well, silly, really. You aren't going to shoot them like that! You are going to put each charge in a separate case. Your "group weigh" thingy has no point OTHER than to try to show you some kind of consistency.

Now, on that note, sure, it will show that but, surely is no way to set up a "batch" of individual cartridges.

Be smarter than the powder, friends. We have minds that are capable of thinking. Laugh if you want but the guy that taped an aquarium pump to his powder measure is thinking. Each charge is going to be in tolerance, if you will, not a part of a group.

To make my Unique, and I have a surplus version with even bigger flakes, to meter correctly with EACH charge, I use the Dillon powder warning attachment to put a little weight on the powder. In fact, I even add a bit of weight to it just to make sure. On my Dillon's, my Unique loads come out to be +/- .1gr sampled every one to start with during setup for the first 10-20 times the handle is cycled. If I have an extended period of time where the press sits unused, maybe a potty break or something that the wife wants me to address, or whatever, I do this all over again just to make sure.

I suppose, once you guarantee that you are dropping charges within the tolerance you want, you can do a test to see if the "system" is working by doing the multiple charges but......not for me.

I want every charge from my automated powder drop systems to be the best they can be, as designed, +/- .1gr.

FWIW

 

[Beemer-mark]

I never knew there was a problem weighing Unique. I use a RCBS powder measure for 357 & 45 colt and a Dillon SD for 45 acp.

 

[Maximumbob54]

When doing statistical analysis, you are exactly right. If all of the loads ended up in one case and you were hoping for a total, that was safe, sure, measure them that way. Have fun.

The problem is, each charge goes into it's OWN case and Paul's scenario just isn't that far fetched, especially with hard to meter powder.

Unique can be a pain to deal with, others too, BUT, weighing many charges together is, well, silly, really. You aren't going to shoot them like that! You are going to put each charge in a separate case. Your "group weigh" thingy has no point OTHER than to try to show you some kind of consistency.

Now, on that note, sure, it will show that but, surely is no way to set up a "batch" of individual cartridges.

Be smarter than the powder, friends. We have minds that are capable of thinking. Laugh if you want but the guy that taped an aquarium pump to his powder measure is thinking. Each charge is going to be in tolerance, if you will, not a part of a group.

To make my Unique, and I have a surplus version with even bigger flakes, to meter correctly with EACH charge, I use the Dillon powder warning attachment to put a little weight on the powder. In fact, I even add a bit of weight to it just to make sure. On my Dillon's, my Unique loads come out to be +/- .1gr sampled every one to start with during setup for the first 10-20 times the handle is cycled. If I have an extended period of time where the press sits unused, maybe a potty break or something that the wife wants me to address, or whatever, I do this all over again just to make sure.

I suppose, once you guarantee that you are dropping charges within the tolerance you want, you can do a test to see if the "system" is working by doing the multiple charges but......not for me.

I want every charge from my automated powder drop systems to be the best they can be, as designed, +/- .1gr.

FWIW

If I read that one more time, I am going to have to try it.

 

[SMSgt]

My antique Herter's powder measure throws HP-38 all day long without varying more than .1 grain.

 

[dickttx]

I never understood the averaging either. I use the Lee Auto Disk, so after I once determine which hole to use for what weight there is no need to average.
The problem I had the last time I used Unique was that a charge would hang up somewhere and drop a light charge. The next charge would knock the rest of that charge down, along with the full amount of the second one. The average was correct, but the first was likely to make a dud and the second a kaboom.
It reminds me of the city's average method of fixing potholes. One is a 4" hole, the next is a 4" hump. On average they are smooth.

 

[kenny s]

I use 4.0 Unique in my .38 sp. and I found that going slowly with the charging handle will give me consistantly good charges. I weigh a lot though for safety sake. I don't want my "new" J frame 5 shot snubby to end up on the gunroom wall at the gunshop.

 

[old tanker]

For me, it just works!

....hard corps Unique users out there???

I have a .45 ACP cast bullet load using Unique that I have been tossing out of a Lyman 55 since about 1961. Nothing else I've tried will group as well. I also like Unique's versatility, it is useful in a lot of cartridges. It is not always optimum, like it is in the .45 load, but quite often it is better than good enough with cast bullets in most cases.

Some folks think its dirty and smoky, but I load a bunch of .38 S&W, .44 WCF, 45 Colt, 38-55 and .45-70 with black powder so that doesn't bother me at all.