RCBS Uniflow Powder Measure

Here is my powder measure stand. I use a floor stand so that it does not get vibrated by actions on the bench.

A Redding 10-X is mounted, but I remove it and install an RCBS Uniflow when needed.

I use the Uniflow for small rifle cartridges, the 10-X for handgun.

JimKirk said:

Nice stand Willy ..

The only problem is ... the Uniflow needs be set up where the dump is on the down stroke ... so unless you have an opening that the measure stem can pass ... you will have to set it sideways ...

If you'll notice there is an opening on my home made stand ... if you look at the RCBS Advanced stand ...it has the same opening ... this is even more "needed" when using a Micrometer stem as it is much larger in diameter and longer than the plain screw stem ...

I have been using the RCBS Uniflow since 1969 ... and have been through several different home made stands ... they have all been scrapped ...

The next "improvement" I plan is a way to make a quick disconnect so I can dump unused powder with out unscrewing the measure...

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I've been staring at my uniflow wondering how to remake the rotors to be like the hornady with quick disconnect inserts. Draining the hornady is simple, replace the insert with a drain insert - which is basically an insert without the guts and no threads.

Another option would be to get hornadys bayonet mount adaptor and use a hornady bushing on your PM. I think the adaptor requires 1-1/4 x 12 threads so you'd have to tap your stand accordingly. Then the PM comes out with about a 1/8 turn.

I thought about modifying the Uniflow rotors to just accept the hornady inserts - but the hornady inserts need a .750 slot in the PM, and I think the uniflow is 0.625, so you'd have to machine the casting.

Just to be different I dump on the upstroke. At rest the rotor is able to fill. It's never been an issue for me - but I dump light and trickle to load. I use the uniflow mostly for bottleneck rifle case on a single stage press, not on my progressive.

My powder measure is a Redding and it has the quick connect.I used a 1 1/4 x 12 nut

JimKirk said:

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I don't know Jim, you think it is strong enough to hold the powder measure??

So, y'all are putting the dump handle so it extends off the back of the rotor, and then you are leaving it in the dump position between dumps, rather than the rotor fill position?

So, y'all are putting the dump handle so it extends off the back of the rotor,

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Sort of, the entire measure is turned around so the adjustment screw is in the back and handle is in the front.

and then you are leaving it in the dump position between dumps, rather than the rotor fill position?

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If left in the rotor fill position any vibration can cause the powder to compact and through off the charge.

Cfullgraf ...

My 46 years of using my RCBS Uniflow ... has proven to me that the down stroke provides better measuring ....

I have never used your Uniflow .... so it may be different ....

Rule3 ... I tend to built based on ... if one screw is good ... five should be better ... !!

Don't know if you saw all the plugged holes in that old bench(it is only about 40 years old).... been a lot of different reloading tools bolted to it ... hard to drill a fresh hole without drilling next to a plug !! Looks like it needs a fresh coat of stain though!

I did a lot of playing with powder baffles in my Lyman #55 powder measures, as well as my old Herters drum type measure years ago.

I could find no measurable difference, one way or another.

But, I try to keep them 1/2 to 3/4 full at all times.

And use the Lyman #55 trip-hammer every up and down stroke of the handle.

IMO: That Tappty-Tap little hammer thing on the Lyman-Ideal #55 is the secret to as near perfect powder throws as you can get.

rc

This is how to set the drum up for down stroke drop on the Uniflow...

Well that's cool! I'm gonna try that! (Light bulb emoji)

JimKirk said:

Cfullgraf ...

My 46 years of using my RCBS Uniflow ... has proven to me that the down stroke provides better measuring ....

I have never used your Uniflow .... so it may be different ....

Rule3 ... I tend to built based on ... if one screw is good ... five should be better ... !!

Don't know if you saw all the plugged holes in that old bench(it is only about 40 years old).... been a lot of different reloading tools bolted to it ... hard to drill a fresh hole without drilling next to a plug !! Looks like it needs a fresh coat of stain though!

Click to expand...

I do the same only I would have over-tightened those bolts to the point of breaking them.

I do the same only I would have over-tightened those bolts to the point of breaking them.

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Got keep a good supply of EZ-Outs and left hand drill bits on hand

Wear it in. My best uniflow (I think I have 4 or 5 now for some reason) is the one I use on my pro2000 and the micrometer small insert. It has done about 300,000 rounds and is very smooth. It throws 800x just fine with +/- 0.1 grn normally with a single baffle.

When I operate it and my newest, the new one is terribly rough in comparison. Fortunately I use it with Rifle without the micrometer so it is less of an issue.

Use it. Wear it in. Cycle a 100K rounds through it and you will get quite good at it and be very pleased.

I wonder if turning my Uni-flow around and dumping on the down stroke would help mine. It has never been as accurate as my hornady but my hornady is case activated and I figured that was why.

I'll have to try that, I bought it in the early 90s and it has never been consistent enough to suit me so it hardly gets used. When I do I use a trickler to make weight.

Okay I flipped my Frankford to operate like you guys. Very cool. Had to tweak the lever to clear the hopper (but then replaced it with a hornady one instead)

I looked over the Hornady measure on my progressives and they did not offer a solution I could see to reverse the mech. With a longer lever fabbed and possibly new holes drilled and tapped it might work.

This has been my setup since the 1980's, measure dumps on the down stroke. I can also pick the whole rig up and dump the powder when done. The measure is just screwed to a piece of counter top with a felt bottom.

P.S. I failed to mention that I'm pretty happy with the way my uniflow measures, I have never used a baffle. It splits hairs on ball powder and does vary up to .3 gr on flake and extruded. As others have mentioned consistency seems to be key, my charge rate on pistol cases is 1.3 seconds per case. The cadence sounds very much like the ticktock of a clock. I up the dwell time on .44 mag, on big rifle cases I'm over 2 seconds, with extruded powders I come away from the top fast so inertia helps cut the grains. I do have to clean the drum and bore with a kleenex wetted with brake cleaner every couple of sessions to get buildup out.

Paddy, I'm going to do that with my Uni-flow and test it as soon as I get a couple grand kids under control.

I put a lot of thought in to things before I buy them and more after I buy them but this idea went right over my head until you guys pointed it out. I expect someone figured this out a long, long, time ago but it passed me by.

I hope it helps my Uni-flow but for some reason I don't think it will. Maybe I'm skeptical from to many years of trying to get it to be accurate beyond .3gr.

I don't think the cylinder fits the bore correctly on mine and it chatters and tightens up at times when stroking it.

When I look at it on my bench, I see money spent poorly and that pains me because it's the only thing I have bought from RCBS that didn't meet or exceed my expectations.

You can also take the rotor out and polish it up on a buffing wheel with some very fine polishing compound ...

You can also polish the casting using a felt wheel in a Dremel .... just be careful and not over do it ... do not polish the cutting edge where the rotor meets the casting ... you need that sharp edge to cut ...

I just flipped mine around and ran about 30 drops at around 3.0gr, 7.0 gr and 12gr each,
It didn't help it. It still jumps around .3gr or more with my best metering powders.

I don't use it much any more and I never offered it for sale because I didn't feel it moral to sell it to someone else knowing it isn't accurate. I know Arch-Angel was looking for one last year.

I moved on to computerized powder measures and the uni-flow just sits on my bench.

OilyPablo,
What about that cutting edge on the drum, mine seems to cut powder on any kind of powder I run through it. Does yours do the same?

Maybe one out of 5 is a smooth transition to dump, I don't notice my Hornady cutting any powder, ever, when I'm setting it up with the easy to meter powders.

I hope to it does. Good luck to you

tightgroup tiger said:

I just flipped mine around and ran about 30 drops at around 3.0gr, 7.0 gr and 12gr each,
It didn't help it. It still jumps around .3gr or more with my best metering powders.

I don't use it much any more and I never offered it for sale because I didn't feel it moral to sell it to someone else knowing it isn't accurate. I know Arch-Angel was looking for one last year.

I moved on to computerized powder measures and the uni-flow just sits on my bench.

OilyPablo,
What about that cutting edge on the drum, mine seems to cut powder on any kind of powder I run through it. Does yours do the same?

Maybe one out of 5 is a smooth transition to dump, I don't notice my Hornady cutting any powder, ever, when I'm setting it up with the easy to meter powders.

Click to expand...

Why not send it back to RCBS for a 'tune up"
Maybe their expert eyes can find the problem that you cannot, they are known for top notch service.