RCBS Uniflow Powder Measure

[mikemyers]

I stopped reloading in the early 1990's, and packed away all my reloading equipment. I was moving to Florida, but somehow never found the room or the time or the need to set it all up again. I'm back now, with lots of free time, so I'm trying to set my old reloading gear up again.

This morning was spent on the press. I then started to clean up my RCBS Uniflow Powder Measure. Actually, I had two of them, one that I had been using, and a spare one, quite rusty, and very dirty. I'm not sure why I even have that second one.




In the early 1980's, the fellow who sold me all his reloading gear came to my apartment and set everything up for me. I was reloading after a very short setup time, following his directions, but I never "learned" all the basic stuff, including how to set up this powder measure, the dies, the scale, and probably a lot more. So, I'm starting at the very beginning.

I took the powder measure apart, and used dry paper towels to clean it up inside and out. It's back together now, but before I mount it, I've got a few rather simple questions about this device:

First, is this still a good option for loading powder manually? Or, have most people switched to something better?

Second, I will be reloading only three calibers, 38, 44, and 45. All I'll be making is "range ammo". Once I find the settings for each, when I switch back and forth later, is manually setting the "Measuring Screw" to the same number as before enough, or do people typically check the powder weight every time after changing the setting? (I plan to make 38 Special rounds to fire in my 357 Magnum guns, 44 Special to fire in my 44 Magnum guns, and a "light" load for my 45 Colt. I don't remember re-weighing things 30 years ago every time I switched to a different caliber. but maybe it's something I should always have been doing.

Finally, I read how there are different kinds of powder, and some load more accurately than others. If that makes a difference are there any brands of powder that works "best" in these RCBS powder measures?

 

[Average Joe]

I check every 10th round for accuracy, Never just set the dial and walk away. Check, and recheck, never assume.

With most power measures, ball type powder works best, I also have an RCBS Uniflow, It does work well with flake powders, but not as good as ball powder.

 

[Jesse Heywood]

For handgun cartridges I have had very good results with the Uniflow. Two items that are useful. A micrometer metering screw and a powder baffle.

 

[mikemyers]

Is this what you're referring to?



.....from here: http://www.midwayusa.com/product/654966/rcbs-uniflow-powder-measure-micrometer-adjustment-screw-large-685-diameter

The Midway page implies that this is only offered for the "large" cylinder only. I assume that you don't use something like this for handgun loads?

 

[rfwobbly]

Welcome back! We missed you.

The Uniflow has 2 different diameter rotors. You'll definitely want to install the small diameter rotor for measuring pistol loads. If you only have one, then the piston and bore should be about 3/8 inch in diameter. The large one is something like 5/8 diameter.

Setup is done by weighing the "drops" each time you setup for a new reloading session or caliber. You get your most accurate setting by averaging 10 drops. Say you want 4.2 grains, then dump 10 and they should weigh very close to 42.0 grains.

All the best.

 

[mikemyers]

Thanks!!

Wow, that's a brilliant idea!!! First time I've ever heard of it. It will average out the ten loads, and give a more accurate result. They should suggest that in the user manual.

I do have both cylinders; the smaller one is still mounted in the powder measure.

(For future reference, is it possible to get the 10 "drops" worth of powder on the RCBS or Dillon multi-stage presses? )

 

[Kp321]

Spherical powders always meter best in any measure. Small grain pistol powders such as Bullseye meter better than flake types such as Unique. A baffle really improves the performance of the Uniflow. I cut up an old credit card to make my baffle out of.
To answer your last question, on a Dillon 550, I pull the locating pin at the measure station, place an empty in the shell plate and cycle. Pull the shell, dump powder in scale pan, repeat ten times.

 

[ColtPythonElite]

I bought my Uniflow in the early 90's. It has served me well. Most of the powder that has gone through it has been Unique. I never used any kind of baffle. It has always given me +/- a tenth of a grain with Unique, which works just fine with my loads.

 

[JimKirk]

I have mine set up with the "dump" on the down stroke instead of the up stroke as in the photo (post #1)... I've found mine to be more accurate with it set up that way....

Like this...



You would need a stand that allows the stem to pass through as does this RCBS one or build one as I did....

 

[rfwobbly]

For future reference, is it possible to get the 10 "drops" worth of powder on the RCBS or Dillon multi-stage presses?

It is possible, but it depends more on the press than the powder measure. Most of the progressive presses are auto-advancing, so the cartridge case moves to the next position after the "dump". And unlike the Uniflow, there must be a case present to activate the dump. So you 1) must have a case, and 2) you have to keep chasing it. It's obviously much easier with the Uniflow where you can beat out 10 dumps directly into the scale's measuring pan.

 

[Rule3]

I have the same measure. The numbers or lines on the ,metering screw or Micrometer really mean nothing. They are just reference points. So you can write down the number when you find "your" load. Then if you change it it will get you CLOSE to the past setting, but you will still have to fiddle a bit to get the exact setting. So no, you can not just set it to the number on the screw it will be different every time. You need to weigh until you get it exact.

Keep the powder hopper full or put a baffle in it to keep the weight constant and prevent fluctuations.

Run a full pound of powder through the measure to "season" it.

Yes it is a very good way to weigh your powder Find the setting and then check every so often (every 10 or so) to make sure it has not drifted.

For your calibers the small rotor is the one to use.

Ball or spherical powders meter better than stick powder.

 

[Jesse Heywood]

Is this what you're referring to?



.....from here: http://www.midwayusa.com/product/654966/rcbs-uniflow-powder-measure-micrometer-adjustment-screw-large-685-diameter

The Midway page implies that this is only offered for the "large" cylinder only. I assume that you don't use something like this for handgun loads?

Yes. That is what I use. For handgun loads, with the large cylinder. I avoid loads under 2.5 grains, which lets me load most 380 auto.

 

[higgite]

It is possible, but it depends more on the press than the powder measure. Most of the progressive presses are auto-advancing, so the cartridge case moves to the next position after the "dump". And unlike the Uniflow, there must be a case present to activate the dump. So you 1) must have a case, and 2) you have to keep chasing it. It's obviously much easier with the Uniflow where you can beat out 10 dumps directly into the scale's measuring pan.

I have a case activated Uniflow mounted on a Pro 2000 progressive press. Whenever I adjust the metering stem, I just use the stem itself as a manual operating handle and cycle it through 10 drops into a pill bottle to get everything settled in. Then I do 10 more and weigh it. If the average is within limits of what I want, then I weigh a few individual drops to check consistency and start loading.

 

[oneounceload]

One of the better powder measures out there; mine is still in use 35 years later. Always consistent and accurate. They make a baffle that makes things even more consistent.

 

[fguffey]

Micro adjust, all of my threaded devises are micro adjust, that includes seating stems, die adjustments and powder dumps. I use the dial caliper like a height/depth gage. I have a micro adjust for the Uniflow, I do not swap it from one measure to the other. I have a Hollywood Gun shop powder measure for rifles, it came with the micro adjust.

F. Guffey

 

[Dframe]

I've been using mine for 40 years now. The marks on the adjustment screw are merely reference marks. They may get you "close". But ALWAYS measure before you start loading and then every once in a while "just because". periodically I recheck everything and reassure myself that nothing has worked loose.

 

[mikemyers]

To me, it's incredible how useful this forum really is!

Thirty years ago, my friend sold me the reloading gear - he "said", and I "did". In all the years I used it, I don't recall re-checking the weight of powder that he had set for me. I had no idea I should check it every so often, let alone after every ten loads. I only did 44 light loads, and 45 (ditto), and I can't recall if I did anything changing from one to the other. Back then, it seemed to me like setting up the dies - once it's done, it's DONE.

Having read all the above, I see so many things I wasn't doing as well as I should have. Once or twice a week I went through all the motions, getting another 100 or 200 rounds to fire that week. It was just a routine - do what John told me to do, and voila, enough rounds to last me for the week!


Powder measure baffles - never heard of them before this discussion. I assume it's to keep the weight accurate, regardless of whether the powder cylinder is full or near empty? Sounds reasonable. I found one on Midway's website:

http://www.midwayusa.com/product/493217/rcbs-uniflow-powder-measure-powder-baffle

 

[mikemyers]

(Just curious - for those of you who have these automated presses, do you stop the routine and check the powder measure every ten or so drops, or do you just run off hundreds of rounds once you've got things working properly?)

 

[higgite]

(Just curious - for those of you who have these automated presses, do you stop the routine and check the powder measure every ten or so drops, or do you just run off hundreds of rounds once you've got things working properly?)

If by automated, you mean progressive presses, after initial dialing in, I check every 10th round until I feel comfortable that all is well, then every 20th round or so. I find that I never have to reset the powder measure during a continuous run, but I still get nervous if I don't check it every so often. I always check after a change/pause in the rhythm and often find the first drop afterwards is overweight, I think due to vibration "packing" the powder into the measure cavity. I toss that one and check again until it's back in the groove.

 

[fguffey]

for those of you who have these automated presses

Can not speak for other members. I know the weight of the components. After getting all the adjustments I start loading, when checking I use the digital scales for testing the combined weight of the components. If the case weight matches , if the bullet weight matches any variation in weight has to be the powder.

I use the powder lock out die for straight wall cases and the powder die for bottle neck cases.

F. Guffey

 

[mikemyers]

Higgite, I haven't yet sorted out in my mind the difference between "turret", and "progressive", and started calling them "automated". Sorry. I guess it's safer for me to just refer to all of them as multi-station presses (as opposed to a single station press that only holds one die).

What you wrote brings up another question.... Years ago, after a reloading session, I left the remaining powder in the dispenser. I would just continue a few days later, and refill as needed (with no thought to the difference in how much powder was dispensed, depending on how much powder was left in the tube. I never knew about "baffles"). .......so many things I know now that I did incorrectly back then.....

Is leaving the powder in the dispenser reasonable if you know you'll be reloading again in a week or two, or is it better to pour any unused powder back into the original powder container?

What I'm also learning in this discussion, is that you don't just walk up to the reloader and start cranking out shells. It's important to check the weight of powder being dispensed every time you go back to the press, and from then on, every 10 or 20 rounds. Not a single one of the YouTube videos I watched said to do this....

 

[Rule3]

No you should never leave powder in the hopper. When you are done dimp it out into the original container.

It may cause the plastic to degrade or you may forget and dump it in the wrong container.

That said, I am sure many of us have left it overnight or a day or so. But that is not the correct answer

Yes, always spot check your powder drop or loads Random checking every 10 or 20 whatever feels right.

I do not agree with taking the average of 10 or 20 drops. All that shows is a average. Some charges may be high some low. If you want 5 grains and one is 6 and one is 4 then the average is 5 but those two are way off.

Throw a few charges set at were you want it. Then weigh each one until you are satisfied it is throwing the same weigh each time. You are then good to go.

As for Baffles you can cut your own, There is a PDF with templates.

Google Uncle Nicks Powder Baffles

 

[Jesse Heywood]

Leaving powder in the Uniflow will etch and cloud the plastic, making it difficult to see the powder level. RCBS will send a free replacement and will also advise you not to leave powder in the measure.

Difference between a turret and a progressive.
A turret is a single stage with a plate that holds the dies, allowing one cartridge to be loaded where the operator raises and lowers the ram and moves the plate for each stage. The advantages over the single stage is that the dies can be left in place without having to be changed. One can process one cartridge or hundreds without changing the dies.

A progressive has a rotating plate that holds multiple cartridges. The plate is rotated and raised with each pull of the lever. And with each pull a cartridge is processed in every station. This means that with every pull of the lever one cartridge is completely loaded. On most progressives there are attachments that will automatically insert the case and bullet, which really speeds things up.

 

[earplug]

Hose washer on lock nut

Take the round lock nut off the powder measure set screw. Add a rubber hose faucet washer and replace the round lock nut.
Now the vibration of knocking the measure up and down won't loosen the settings. And you don't have to tighten the lock washer as much.
Bang away.

 

[armoredman]

Been using a used Uniflow since I started, have a weird stamped accessory deal that lets me use the press as the stand, with the other end held screwed in by a die. It's a great powder measure.