RCBS uniflow powder measure issues


August 2, 2007, 02:13 PM
This is what I am using in my first attempt at reloading. Problem is, I cannot get a consistent "dump". The weights are all over the place from .2 -.4 grains all the way to over one grain difference. So I have to use a trickler to add when under weight or pull some out when over. This is using IMR 4831. Is this normal? For my 7mm loads it is an annoyance since I am only loading a small volume but, I would like to do some plinker loads for my AR (.223) and this would be a major PITA!

What do I need to do:banghead:


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August 2, 2007, 02:44 PM
I'm having the same problem as well. My pull is very uniform but still, there's not much I can do. Even when I'm metering Bullseye, it can go anywhere from +.2 to -.2, and as a result, I'm forced to weigh each load individually.

With Varget, forget it. It goes to as much as .5 grains over what I'm loading and that's unacceptable as well as dangerous. I measure each load with that, too.

August 2, 2007, 02:49 PM
With long extruded powders and large flake powders, many powder measures have some problems. Parts of the powder are being cut as the handle is thrown. Ball powders, small flakes and extrusions work very well. Using the Uniflow with powders that don't meter well, I just get close and trickle in the rest.

August 2, 2007, 03:13 PM
Thanks for the info. I wasn't sure if it was me or the uniflow. My guess is something that flows really good for doing the .223 since I am going to be doing lots of them.

August 2, 2007, 03:30 PM
I've used or seen friends use probably most every powder measure ever made, and the only one that is really accurate with long stick powders is the Belding & Mull:

Look for them at fleamarkets, garage sales, and places like craigslist. I bought one last week for $20.

For everything else, aim a little low and use a trickler to bring it up to the final weight. With the other measures, it's also nice to have a pharmacist's spoon to enable you to pull a few sticks out, if the need arises.


August 2, 2007, 03:47 PM
my Uniflow is spot on accurate with H870, H380, 296, H335 and Power Pistol.
I hand weigh all H4831, H4895 and 3031 powders.

August 2, 2007, 04:14 PM
Have you thought of trying a Lee autodisk? I use a Pro Autodisk with double disk kit for loading .223 with Varget. It never varies more than +/- .1 gr. and it's usually within .05 gr. Wouldn't hurt the pocketbook much to try it.

p.s. I don't think the autodisk can handle large cartridges like 7mm.

August 2, 2007, 04:27 PM
The shorter your stick is, the more accurate most measures are.

August 2, 2007, 04:34 PM
I found the trickler to be exactly what I needed to start cranking out loads fast, while still being able to weigh each charge on the 505.

Right now I crank out a ton of .45 ACP using bullseye with a good reloading area layout where I'm pulling primed cases from a container with my right hand and putting charged ones into the block with my left. It's good quality control. Each charge gets weighed, and it takes very little time for a single stage.

August 2, 2007, 05:00 PM
What do you need to do? I switched to H335 for .223 and went to HP38 as my Unique replacement. No more problems. If I get really picky I use my Lyman 1200DPS to trickle out each charge for me. Even on a 40+ grain charge it keeps up on the single stage no problem. Forget about it on the progressive.

August 2, 2007, 06:50 PM
Make sure you have a powder baffle in the Uniflow, and then practice a consistent 'bump' at the top and bottom of each cycle.

August 2, 2007, 08:21 PM
The H4831SC stands for "short cut" referring to the length of the sticks in the stick powder.

The SC is less of a battle with the Uniflow.

My problem is Power Pistol left in the Unflow dissolves the green hopper:(

August 2, 2007, 11:28 PM
Thanks for all the great info. I loaded my first rounds today. Just got close and trickled in the rest. Everything went real smooth. When I get to the 223 I will look into some other methods.

August 3, 2007, 07:17 AM
Might want to check this out as well:

I haven't tried it with 4831 yet but I understand that's what it was designed for.

Peter M. Eick
August 3, 2007, 07:56 AM
The uniflow can be quite accurate, but you have to do a few things to it first.

One get a powder baffle.
Two get a micrometer set for the pistol and rifle cylinders.
Three, sit down, relax and then just run a couple (yes more then one) of pounds of powder through it and develop a simple cadence.
Four, now that you have a rhythm, drop a charge, weight it and write the number down, now repeat 50 times. Try to learn how YOUR style of using the measure can get you good accuracy.

The uniflow is about repeatability and consistency. My two are about 10 years old now and I have loaded over 150,000 rnds on one about about 20,000 on the other. Both are smooth, and I can routinely throw +/- .2 grns on 4064 without really trying. If I concentrate I can get that down to +/- .1 with a bit of effort. This is on a 40 grn charge.

If you really want to solve the problem, just get a powder dispenser. Here is a picture of my setup doing 30/30's.


August 3, 2007, 09:24 AM
My brother got a used Uniflow at the gun show, and complained that it dispensed on the up stroke. I showed him that it was just not assembled correctly:)

August 3, 2007, 11:09 AM
I only use my rcbs powder measure for ball and flake powders. For all of my rifle powders, stick powders, I use an electronic powder measure/scale. I just dial in exactly what I want (example: 58 grains H4350 for my 30-06) and push he "dispense" button. It automatically throws the charge and trickles it right up the mark. Greatest thing I ever bought for the reloading bench. Well worth the money. I used to scoop and trickle all of my rifle rounds for the exact reason you mentioned. But with the electronic scale/measure I have never looked back. Money well spent.

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