What's wrong with my RCBS powder throw measure?

F

FLChinook

New member
Oh, the frustration!! My tried and true RCBS powder throw measure (you know, the one with a green cylinder atop a measuring chamber that you crank once to throw a charge into a scale cup which you then measure, in my case with an RCBS digital scale) has become totally erratic. One throw is 50 and the next throw is 40.... and on and on. It hasn't been used in about a year but it lives in a totally air conditioned environment.

What could have happened?

Should I toss it and get something better?

What's the best (considering value for money and the fact that I typically reload maybe 1000 rounds/year)?

Thanks
 
What about the scales?
You probably can see if something broke or fell off the mechanics on the powder measure, but can you see inside the guizzmoes on the scales? I never measure powder with digital scales, i have one, use it to weight ever thing but powder.
 
I never measure powder with digital scales
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What do you use to measure powder? It must be really good (read that as reliable and consistent) if you don't weigh... Are you reloading rifle, as I am...
 
Was the powder measure stored with powder in it? If so, empty the powder and start fresh. It may have become clumped resulting in erratic charges.
 
I haven't tried Reloader 25 specifically, but my RCBS Uniflow does not throw stick powder very consistently. Another issue is the plastic fitting on the discharge. Using the small one often causes part of a stick powder charge to get stuck, throwing a very light charge, and often clears on the next charge, throwing a very heavy charge. As a result, I double tap each time on the dispense stroke, which usually clears any stuck granules.
 
Was the powder measure stored with powder in it?
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No, I always empty the Uniflow.

I haven't tried Reloader 25 specifically, but my RCBS Uniflow does not throw stick powder very consistently. Another issue is the plastic fitting on the discharge. Using the small one often causes part of a stick powder charge to get stuck, throwing a very light charge, and often clears on the next charge, throwing a very heavy charge. As a result, I double tap each time on the dispense stroke, which usually clears any stuck granules.
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I find the same thing... which makes me wonder about being able to continue using RL25 in this device. I always get a very large second dispersal with a second and third tap.

I haven't tried doing a double tap on the charge part of the cycle. Anyone doing that?
 
I just examined my stock of powders and I don't have one that's spherical; all are cylindrical.
But I've used them all at one time or another in this Uniflow. All have definite "sticking" effects as the cylinder has to shear off pieces of powder. But I've always in the past had reproducible charges within half a grain... until today.
 
Have you tried to disassemble and clean the chamber in the powder throw ? I found a dead spider inside my Hornady throw once when it was acting wacky. There is not much that can go wrong with any of these units, they all are just a hole in plastic or metal and as you turn the adjustment screw in and out the volume of the hole changes. Hornady, RCBS, Lyman, Lee perfect powder throw and even the Harrel are all based on the same basic design.
 
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Its the nature of the beast.

You charge low, then you use your trickler to top up to the right level.

Lyman makes an electronic scale that has build in trickler, or you can get an auto dispenser (Lyamn or RCBS makes a pretty low cost one now, something around $160 on sale)
 
First I'd get something like check weights or another scale to confirm your digital scale is accurate . My little cheap Hornady scale just went south one day and started measuring everything off by 15gr+ .

Have you tried to disassemble and clean the chamber in the powder throw
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If the scale is working properly then completely cleaning the powder measure would be my next step then lube with graphite .

Maybe try some fine ball powder which typically measures well and see if it works with that .

My powder measure ( Hornady ) does not throw stick powder very well but nothing like 10gr off . I get +/- .4 so a total of .8gr and that is huge IMO so 10gr is , well ridiculous . Something is defiantly wrong with either your scale or the powder measure .

Hmm , could you by any chance be using old powder and or contaminated powder that is clumping ???

Also I do know the longer stick powders can bridge in the powder measure causing a log jam effect . Which has happened to me but this generally does not consistently happen . If it does happen I may not see it again for a thousand more throws.
 
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If my Uniflows all w3ent south I still would not be out of business, I have at least 5 Uniflows and all 5 have a large and small drum. And then there are scales, there are not many I do not have/ I have check weights by Ohaus, the one set I use the most is the one with 47 pieces of check weighs. Electronic? I have two, the electronic scales are high maintenance and expensive, I spend more time bragging about owning them than I spend using them.

And then there are those auto dispensers, I have two that are RCBS.

My favorite is the Little Dandy by RCBS, I have 22 rotors.

I also have powder measures that are brown and blue.

F. Guffey
 
I haven't tried doing a double tap on the charge part of the cycle. Anyone doing that?
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Yes and no. I am using a Lee "Perfect Powder Measure," not the RCBS, and I'm happy with it so far. I've been giving the mechanism a little flick to make sure it drops all the powder. I also only load pistol so I like the setup. But I DO tap the powder measure just kinda out of habit.
 
FLChinook said:
I haven't tried doing a double tap on the charge part of the cycle. Anyone doing that?
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It's my standard practice to double tap at both ends of the stroke. But there are still times with the long extruded powders that part of the charge gets stuck, especially with the small plastic drop fitting in place (a little less with large drop fitting in place). Due to the poor consistency with those powders, I weigh each one. I can usually tell when part of the charge doesn't drop when I put it on the scale since it's typically several grains light. In that case I put the pan back under the measure and give it a couple more taps and the remaining (stuck) charge will dislodge and drop in the pan. Then I trickle in the rest.
 
I will run an experiment with a listed powder, and see how mine does, in regards to a digital, I run almost all stick powders. 4831, 4895, R17 etc.

Certainly varies a good grain but not 10.

Its 35 years old, I don't recall it ever being spot on with stick powders.

I always set it up low and trickled in the beam, then the Lyman scale with the built on trickler (that's my backup as it goes pretty fast - a good second digital check as well as general weighting)

Agreed on the scale check, zero it and then weigh your check weight.

I think I have 5 of those around now so I can cross verify as well as known pan weight.
 
I started reloading 25+ years ago with that same unit . Went with the RCBS ChargeMaster 1500 , made life much easier. Reloading should be enjoyable not frustrating. I double check with the GemPro 250 scale for bench rest rifle loads, super accurate. Hornady sells a nice powder thrower , just as good as the 1500 at half the price . I mostly reload for rifle 308 using IMR 4064 when I'm looking to fill the case with 41.5 grains I want it to be 41.5 , 41.52 is only one piece of 4064 , .02 of a grain will not make a difference but that's just me. I not loading a large quantity at a time.
 
Yes and no. I am using a Lee "Perfect Powder Measure," not the RCBS, and I'm happy with it so far.
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I use a Lee in my portable range box, with stick it is more accurate than the Hornady which cost me 5 times as much and with ball and flake it is dead on. Someone on here suggested to get multiple Lee's and keep one set on up for each common load you use. Next time I do a order I think I shall drop a couple onto the order
 
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