RCBS Uniflo Woo's

[Garage Dog]

I just recieved my first RCBS product, the Uniflo powder measure. I only have experance with my Lee Pro Auto Disc loading Clays so I am looking for some guideance here.

The RCBS was purchased because I want to load 7.62x39. I have a pound of IMR 4198 which I hand measured 24gr of the 4198 before the RCBS showed up and and really liked the way it shot.

I know that 4198 is not known to meter as well as some other powders (didn't know when I bought it) but I'm getting .06gr difference!!! It will throw 4 or 5 load within an .02 high and low and the next one might be .06 higher than the lowest.

Now for the measure itself. The measuring cylinder has roughly .35 play side to side. The hole in the cylinder where the powder goes does not open all the way, there is about .30 still showing in the hole when veiwing without powder. Also, the throat is very rough.

My question is this typical for the uniflo and I'm getting inconsistant loads due to the powder or do I have issues with the measure.

I tried to call RCBS customer service this afternoon but I was 20th in line and didn't have time to wait...I know they are extremely busy and none of this is bashing RCBS in any way.

 

[bowman1962]

Keep the hopper full and try to use a smooth even motion with each handle pull. I have heard that some people have more consistent results by installing a baffle and wiping the inside of the tube with anti-static dryer sheets. It takes a few dozen times when I first get started to get in a constant motion to keep charges within my + or - threshold of .03 but I have never been a stickler for perfection either....

 

[jinxer3006]

Two questions:

1. Where do you guys get scales that read to hundreths of a grain?

2. What are you doing that you want to be within .03 grains?

 

[oneounceload]

^^1.....There's too much variable with stick powder to say that it is the RCBS fault, and .06? Really? Don't know too many who wold complain about that. I doubt you could disassemble the best premium factory ammo and be that close

 

[Garage Dog]

2. What are you doing that you want to be within .03 grains?

Make that .6

Keep the hopper full and try to use a smooth even motion with each handle pull. I have heard that some people have more consistent results by installing a baffle and wiping the inside of the tube with anti-static dryer sheets.

I tried the baffle and the anti static dryer sheet. The baffle was actully worse.

 

[mnhntr]

I have one that I use with H4350 without a problem. I use a baffle I made and the static sheets. I also bought the micrometer attatchment.

 

[jinxer3006]

QUOTE] Make that .6 [/QUOTE]

Something is severely wrong then. My 2 uniflows always throw within .1 grain and I don't worry much about working the lever consistently.

I'm not home now so I can't check mine, but your side play and overlap numbers sound high. It almost sounds like it may be assembled incorrectly (or some part is way out of spec).
T
Any chance you can post some pictures of the drum and metering screw?

P.S. sorry about the "hundredths" comment, but I couldn't resist.

 

[Garage Dog]

I just tried it with the powder only showing about 1/2" up in the glass...it metered MUCH more consistently!

I think I'll just use up this pound of powder and find another that meters better.

 

[Garage Dog]

P.S. sorry about the "hundredths" comment, but I couldn't resist

No offense taken, that was fair game material.

I'll post pictures tomorrow. Maybe I'll have a chance to talk to RCBS tomorrow.
The side to side play is what's bothering me the most.

 

[ford8nr]

I find with smaller charges if I tap the side of the handle twice before operating it I can get within .1gr otherwise it's more like .4 Helps settle the powder.

 

[Clark]

I have been reloading for ~14 years and I am now up to.... more dies today.... 65 cartridges.

The RCBS uniflow powder measure is one of the very few things that have not fallen by the wayside.

I am still using it.
.. despite the crunchy feel with long stick powder.

 

[KansasSasquatch]

The UniFlow is very similar in design to a Hornady powder measure. Neither of my Hornady measures have that much side to side play with the rotor. You should post pictures of the empty measure or send some to RCBS. It may very well be out of spec. Not too long ago someone posted pics here of a Hornady measure that was well out of spec, it could certainly happen to an RCBS product too.

 

[Garage Dog]

Well, I spoke to RCBS yesterday and he was most helpful. To boil down our conversation he said that IMR 4198 or any stick powder tends not to meter well, which we all know (I just found out....) Anyway he said 4198 meters best when the hopper is NOT full, rather the lighter load in the hopper is best because that type powder tends to pack tight and that hinders metering. He suggested a baffle.

So here's what I did. I put powder in the hopper only about even with the with the bottom of the plastic. Sure enough, it metered better, in fact I thought I had it made. It meters 5 or 6 loads within .2 and then for some reason it will go .4 under or .4 over, and then meter another 5 or 6 just fine. His suggestion did help, so I made a baffle and filled the hopper 3/4 full and got the same results.

As crunchy as 4198 is I think I'm just asking the Uniflow to do something it's not built to do. I'm just going to use up the 1 pound that I have and look for something that meters better in the Uniflow for what I'm loading.

Right now I throw a load into a case, dump it the pan and weight it on my beam scale, If it's ok, and most are, I dump it into my prepaired cases and move to the next one. If it's heavy I just dump a little out and if it's lite I just trickle a little in until the scale tells me it's right where I want it. It goes pretty quickly and I KNOW each load is correct.

 

[jinxer3006]

FWIW, I finally made it home and checked both of my Uniflows. The side-to-side play is about .045 on the one I have set up with the small insert and .065 on the one set up for large. I don't see any overlap of the hole with either one.

When you gave your measurements, did you mean .035 and .030 or were they actually .35 and .30?