Powder measure variances

J

JohnAengus

Inactive
I have the Dillon RL 550b and reload 9mm and 10mm for shooting at the range. What are the tolerable variances for the powder measure granins? Sometimes I get up to a 0.4 grain variance between powder drops.

I used a chronometer to measure FPS on different loads. Once set of 20shots showed an Exreme Spread of 69 FPS, one 99 fps, and another 133 fps. On some factory new rounds the extreme spread was 35 FPS.

Is there an upgrade for the Dillon powder measure that would drop more consistent loads? Does this mean anything to me as I just target shoot at the range?

Thank you.
 
Welcome to TFL

Inconsistent powder throws almost always have more to do with the powder type ( extruded , ball , flake etc ) then the powder measure it self . I don't use the Dillon but do use the Hornady , Lee auto drum and Lee pro auto disc . As far as I can tell they all throw the same powders to about the same variances . Small ball type powders throw great while flake powders throw OK but not as well as ball . Extruded ( stick ) powders are by far the worst for me and the longer the stick the worse it gets . I just so happen to have been throwing IMR 4064 yesterday and was getting a +/- of .3gr for a total of .6gr in variance and that was with the Hornady powder measure .

What powders are you using ?
 
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Metal god said it correctly, it's the powder type not the measure in most cases. My Dillon's all throw very, very consistent charges with some powders (like 296, 231, and several others). Powders like Unique, etc aren't nearly as consistent out of any of my measures. I've found Dillon's powder dispensers to be as good as any I've owned. One other thing...how you pull the handle each time makes a difference also. Use the same amount of force and speed each time and your variation will decrease with all powders.
 
I also agree on the powder measure. Powder type makes more of a difference. Though I've found the cheap Lee auto-disk is fairly accurate with some of the courser powders until it wears in and starts to leak.

On another note, however, I have a mostly full power 9mm load that varies .3 gns (target charge is 6.4gns of HS6) and it is more accurate for me than factory ammo. I haven't measured extreme spread, nor am I overly concerned with it as accurate as it shoots.

.4 gns variance can be a lot, or it can be not that much. What is your target charge weight? Is it 4gns? That's a 10% variance. 8 gns? 5% variance. One is a lot, one would be within my tolerance of "OK."
 
I just happen to be using Unique. I do have some IMR 4756 and some Hogden on hand. I’ll give them a try. For my target shooting, are those variances going to make a difference in my shooting? I’ll pay more attention to my arm movements too. Thanks
 
I like Unique powder....a lot in some loads. It's just not a good choice for what you're using it for. Pick another powder, preferably a ball type powder and you'll be amazed at how well it meters. Unique works better in large capacity cases and on non-progressive presses. I think you're on the road to success, good luck.
 
Thanks everyone, I appreciate the info. What are some ball powders? I shoot 9mm. I have quit a bit of Unique - bought a lot when Obama was in office. I’m not having any problems with my shooting. Probably a good reason to shoot more!
 
I do use Dillon throwers


Three common ways to even out powder throws,
One is to use a bigger baffle than the little baffle in the Dillon. I would punch a small hole in it and put a string through it so it can be lifted out easily.
Baffles are cheap.

The second is a spring on the charge bar. Older Dillon throwers had a spring, it still works on the newer ones. Do a little search and you will find pictures of these to show you where to place a rubber band or one of those ponytail ties to try this before you hunt a spring up.

Something that has worked particularly well for me, particularly with ball or flake powder, is a couple of thick metal washers duct taped together (again, with a string) and placed on top the powder.
A little extra weight on top keeps powder flowing, particularly when the bin gets lower.

If you decide to 'Polish' the charge bar, as some will recommend, I suggest you tread lightly.
Use a dead flat surface, like plate glass, and take as little off as possible when lapping/polishing.
The smaller you make the charge bar, the more leakage you will get around it.
 
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In addition to CFE Pistol, HS-6, Autocomp, Power Pistol, BE-86, and #7 are other powders you might consider for the 9mm and 10mm. All of those should dispense better than Unique from the Dillon powder measure.
 
Dillon powder variance

Small ball powders work great. Always with in + or - .01. Now, 5744 which is a extruded powder gives me all kinds of fits.

I use it in 45/70 and 458 Lott. I am not sure why but the larger the case the more off the throw can get. On the Lott loads I make get as much as a .07 + difference on powder throws. ( I am shooting light loads so super precision is NOT my main concern. )

I actually tend to load the Lott 1 at a time because the powder dump is more consistent. In 223 and 243 I used AA 2200 data powder that is a fine ball powder. Back to + or - .01.

It is very powder type dependent. One trick I have found helpful is when you are setting the powder throw make sure you are decapping and resizing a case on the throw. It seems to make a difference.


Dan...
 
Several people mentioned how the type of powder makes a difference in the uniformity of a powder measure's throw. This is true.

Not mentioned but also important is the uniformity with which the measure is operated. Things like bumping the handle at the top or bottom of the throw, or using the "knocker" found on the old Lyman No.55 powder measure, to prevent/minimize bridging of powder kernels to provide a uniform dump.

The measure on a progressive would seem to be uniformly mechanically operated by the mechanism, but I have found that while its usually true, its not always true.

I had an Dillion 450, back when they were just being replaced by the 550, and despite it having a spring on the powder charge bar, it would sometimes, stick, and even do so with ball and flake powder.

Other things that make a difference are the presence or absence of baffles in the hopper, and the weight of the powder column.

Measures are used for convenience when speed or ease of loading is more important than exactly identical weight charges. I stopped using progressives over a decade ago. Too many things happening at the same time, for the amount of precision I prefer. With standard loads in pistols, I accept the small variance in charge weight, it's inconsequential. With max level loads, and in rifle rounds, I set the measure to throw a little light, and bring each charge to the desired weight with a powder trickler.

Scoops can be accurate enough, but you need to be consistent in your method of use.
 
JohnAengus:

Unique has been prized for its versatility for about 118 years. No, it will not measure as closely as a finer grained powder. It still shoots. Your velocity variation may be more due to inconsistent burnup than charge weight variation. Are you loading to the maximum? Reduced loads are less uniform than top loads but a little fluctuation is better than more blast and kick than you care for.

Load your Unique, the practice will do you more good than the Powder of the Month Club.

P.S. 4756 is highly desirable in some circles, like USPSA match loading. Too bad it was discontinued, but the volume market was no longer there. You will likely find it shoots well in one or more calibers... or you could trade it off.


The factories load ammo by volume. Hatcher described the time when a long grain powder gave better accuracy than a short grained powder that measured more precisely. The long grain was therefore chosen for loading National Match ammunition. Shooters pulled bullets and complained over the variation, but the targets told the tale better than the scales.

I once had to pull down smoke and water damaged ammunition to salvage the brass and bullets. I wish I had taken the opportunity to weigh some factory powder charges - those that weren't soggy from water penetration, don't believe that your ammo is perfectly sealed just because you ran a few through the washing machine and they still fired - to see just how close they ran.
 
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I learned to love my powder throw and old school beam scale. My Chargemaster has not thrown a charge in 6 or 7 months now I think.

The three things to remember when using a throw is #1 consistency #2 consistency # 3 consistency

The powder needs to be exerting the same downward force when the cylinder is loading. I have used three methods

- baffles. I made mine from a Pepsi can using UncleNicks templates- google it

- weight - about 8 oz of fender washers the are just smaller than the diameter of the powder reservoir threaded on a long bolt and lowered onto the powder column.

- a funnel - fill the reservoir with a funnel but fill it also and leave it in place. As the level in the hopper drops the funnel will let just enough in so that the powder column remains at a constant level

Also consistency in operation. I throw stick 90% of the time so when operating I do a double tap with the handle before dispensing the powder. Tapping the side of the throw with a small weight between throws like the tapper on the Lyman 55 helps settle the powder in the cavity and reduce the cut kernel sticking points

with practice you can get +or- .1 most of the time with a occasional .2 low or high. I like using a small bowl of powder which I trickle to weight with thumb and forefinger to get to exact weight
 
OP, charge variance means less to accuracy than many make out... to a degree. .4 grains variance on a 4 grain charge is a big variance. Did you run a test to see how many charges thrown are at the extreme spread of the variance? For instance an example: out of 100 throws 90 of them are within a .2 range, 6 are within a .3 range, and 4 are within a .4 range. 90% of the rounds are in a good close range (less than +/- .1), 6% or not as close but tolerable (+/- .1), 4% are marginal. I could deal with this. If the same test revealed that the powder charges were all over the place, I would be more concerned.

A .3 gn range is still a target charge +/- .1gn. For example, it drops at 6.3, 6.4, and 6.5, you're basically throwing a 6.4gn charge +/- .1. I don't know about anyone else's standard, but that is plenty acceptable to me if I'm loading bulk blasting ammo.
 
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Start Simple!

Start Simple!: First up I'd check up on mechanical aspects of my 550B. Do you have the correct tension of the activating rod on you measure. Look for warn nylon bushing on the rod. Stuff like that. To me, Unique has gone through my has not been a problem. Charges are checked on a Dial-A-Grain scales every twenty rounds. No "Slam, Blam, Thank you Mame" voodoo reloading. Another suggestion is to call Dillon for help. You may have two problems. One with your machine. The other would be with your loads.

Your velocity swings, to me, look not so good. Might do well to double check you charges in you loading manuals. I'm not sure about comparing with factory ammo. If possible, check against other Unique data using a similar bullet etc.

Addendum: Which is the big offender on velocity spreads. I'd start by taking a look at 10mm. You may find this goes away with a slower powder. Been loading that round for years and have used slower powers without a problem.
 
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I recommend keeping powder hopper as full as possible and regularly refill as you go, trying for no more than a 0.5” difference. It helps to maintain the same pressure from gravity feed and will get a more similar weight of powder in each volumetric drop. You will never do better in consistency using volumetric drop than the powder has consistency in its density... and every jug of powder may have variation from the last.

Verify weight every 20-30 powder drops or so if you really care about getting low variation in the velocity. It takes mere seconds to drop the powder twice and toss one in the balance scale while you keep reloading.




Andrew - Lancaster, CA
NRA Life Member, Calguns.net contributor, CGF / SAF / CRPA / FPC / USCCA member
 
JohnAengus, are you still here?

I loaded a fair amount of pistol ammo with 700X which is also a large flake powder.
I did not get uniform powder charges until I put a vibrator on the Dillon measure. I used a $6.00 aquarium air pump, a coat hanger and a rubber band. No doubt you could think of other sources.
Charge weights weren't perfectly uniform but they were a lot better.
 
I'm still here! What a wealth of good ideas to try. Everything should be nice and clean, I'm going to make anyway. I'll bet it is the shape of the Unique powder, that makes the most sense to me.

No problem with all the off shoots, it helps me learn more and more. I worked the last three days so I am going to sort through everything this weekend. I am confident everyone's input will help.

Thanks a million everyone! I'll post what I tried and how it worked.
 
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