RCBS Uniflow Powder Measure

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OilyPablo

OilyPablo

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Using Longshot, my standard RCBS powder measure and it's just not consistent. I try to be even handed, hold it plumb and all, but: .1, .2 and sometimes .3 gr variance. Am I doing it wrong? Should I try something else?
 
Consistency is the name of the game so keep working on it. .3 grains of longshot is nothing, if you're keeping your loads within .3 grains I wouldn't worry about it.
 
I like to use a baffle in all my drum style powder measures including my Uniflow.

Make sure the peak of the baffle is perpendicular to the rotational axis of the drum so that the holes in the baffle are not directly over the metering cavity.
 
Is it NEW?

is it "broken in" (coated with powder?

What cylinder is in it and how much are you weighing?

A baffle can help or keep it full of powder up to the top
 
It must be either your method or your measure has something wrong ... mine will drop Longshot to within 1/10 grain ...

Do you have it set up to dump on the upstroke? If so try turning it around so that it dumps on the down stroke ... much easier to get consistent motions with the down stroke ...
 
I made a baffle out of copper flashing material I had laying around. It works fine in my Hornady measure. Its a pain in my rcbs measure. My uniflow is old, the insert won't come out of the bottom of the rotor - you have to drop it out through the hopper. My baffle is a tight fit and hard to get out. I need to make up another one that fits somewhat looser.

Or get new rotors and inserts for the uniflow (assuming the newer ones are better designed)
 
OilyPablo said:
Baffle? Please describe or provide links/pictures. There is no baffle.
Click to expand...

I have not seen scientifically valid proof positive without a doubt evidence that a baffle really helps that much.:)

Keeping the powder hopper almost full at all times serves the same purpose.

The "theory" is that it keeps consistent top weight or pressure on the powder at all times. I "argue" that it is simply a hole that fills up with powder and it is not enough to compress it and change much of anything, Like an hour glass with sand,

That said, I have one in mine just in case:D

Yes I made it.
 
I've found that you get best accuracy with the Uniflow by including a baffle and mounting the Uniflow on a press with the Uniflow Linkage system. For some reason the press and linkage creates better consistency than mounting the Uniflow stand alone and relying on your technique to throw charges.

I tend to mount the Uniflow on my RCBS Rockchucker with the Uniflow linkage for loading rifle cartridges and it is very consistent with a wide range of powders.

Hope that helps...
 
Do you have it set up to dump on the upstroke? If so try turning it around so that it dumps on the down stroke ... much easier to get consistent motions with the down stroke ...
Click to expand...

+1 That will help a lot. As far as I am concerned most people, including RCBS have them backwards.
 
I've measured Longshot on a Uniflow using a data logging digital scale thus taking a significant number of samples. That's about what I'd expect for Longshot, maybe slightly worse. It's not the smallest flake powder. Good stuff though.
 
Another thing that helps is before using for powder measuring running some graphite powder through the measure like you would measure out powder. I found an older Uniflow at a garage sale once that was very crunchy feeling when measuring out powder. After smoothing out the drum with some 0000 steel wool and running some graphite powder through the measure it is super slick now. The graphite smooths up the operation and does not contaminate the powder.

Just my .02,
LeonCarr
 
In the search for better/more-consistent drops of challenging powder (700x in my case) i did the whole polish/baffle/graphite "tune-up" on my Dillon powder measure. Seemed to help a lot. The polish took about 15-25 minutes (depending how many interruptions). I didn't go all the way to "mirror" shine, but a nice shiny polish.

I've found that smooth/consistent is the best way w/ my setup. I can definitely see and measure a difference after a rough or jerky lever pull on my progressive. Maybe not apples to apples with the smaller lever and bench mount vs on a progressive. I'd still think a smooth motion will help give you consistency.

HTH - GL!
 
Baffle & small cylinder. I've never used Longshot, but I don't measure 800X on a Uni-flow.
 
OilyPablo said:
Using Longshot, my standard RCBS powder measure and it's just not consistent. I try to be even handed, hold it plumb and all, but: .1, .2 and sometimes .3 gr variance. Am I doing it wrong? Should I try something else?
Click to expand...
You say hold it plumb.? If you are holding the powder measure in your hand that is the problem. It needs to be mounted solid. And as already said you need to be consistent with how you move the handle. Setting it up to dump on the down stroke of the handle is good advice. That is how I do it. I thought I was the only one.
 
Yes, I hold it as I dispense to my brass in trays, goes fairly fast, 50 at a time. Very safe and consistent as I double inspect before setting bullets and seating them. It does take a bit to set the amount, but I guess after reading all the tips I haven't been THAT bad for hand dispensing.

I have ordered a stand for the dispenser, so I will change my methods.

I do have it set to dump on the downstroke. I could see the hand can mount either way and it made more sense from the get go.

Wow just lots of good suggestions. And yes someday I will go more automated.
 
Will do. The original guy who showed me how to reload was holding the dispenser........pain in wazoo. I ordered the RCBS on sale holder ($18) Saturday, will be here Friday!!!

Wish I ordered the baffle!!
 
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...
 
JimKirk said:
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 ...
Click to expand...

The Uniflow does not have to be set up to dump on the down stroke to get good results.

I've tried it both ways and I get the same results (variation of powder charges, etc.) dumping on the up stroke as on the down stroke.

I find it more convenient to operate the powder measure dumping on the up stroke.

I operate all my drum style powder measures dumping on the up stroke (Uniflow, Redding 10-X, Midway Indispensable)

In my opinion, neither way is right or wrong. Just the preference of the operator.

Nice powder measure stand. Look at adapting it to use the Hornady L-N-L bushing or Lee's Breech Lock bushing to get a quick removal feature.
 
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