RCBS Uniflow inconsistency

[bthr22]

I'm brand new with reloading, and after measuring a couple loads out by hand, I decided to try my RCBS Uniflow. I would get it adjusted right where I wanted it, then on the next throw, it would be off. So, I put the powder back and did another (thinking maybe I just didn't have a consistent pull) but it would be even worse, or off in the other direction (i.e. too heavy, then too light). I've made sure my pulls are consistent, and ran about a pound of powder through before trying any loads, but that didn't seem to help. Is there something I'm forgetting? I was using IMR 3031 powder. Thanks!

Bthr22

 

[NeuseRvrRat]

how much deviation are you getting? stick powders like 3031 are known for sub-par metering.

 

[Spammy_H]

Sorry to ask a stupid question - but did you clean it before using it? Most powder measures are shipped with a heavy grease to keep from corroding. Clean it out with a degreaser, alcohol, or Hornady One Shot Cleaner/Dry Lubricant.

Then run a pound of ball or flake powder through it to "season" it.

If you've already done this, how much variation are you getting?

 

[Steve in PA]

When reloading with stick powders, I set my RCBS to throw on the light side. I then use a trickler to add the last bit of powder until I get what I want.

 

[cfullgraf]

Good point to make sure the measure is clean of preservative.

The key to using a drum style powder measure is doing it the same way every charge. Admittedly, when cutting the kernels of stick powders that may seem difficult.

I find better results with my Uniflow when using a baffle. I place the line between the holes of the baffle parallel with the rotational axis of the drum so that a hole is not directly over the metering cavity.

Others have different results with the baffle so it is definitely something to adjust to fit your charging style.

Throw about 15 to 20 charges or so before actually measuring a charge after you first fill the hopper on the measure. This settles the powder column.

Also, I prefer to vibrate the measure as little as possible when throwing charges. Other like to tap or wrap the measure with the metering stop to help settle the column. Again, this is part of the consistency thing. Do it the same each time.

A little variability is normal and your rifle will not be able to tell the difference. I routinely get about plus/minus 0.1 grain when throwing H4895 or Varget. These also stick type powders.

Hope this helps.

 

[Hungry1]

Using a baffle helped me. My Uniflow has definitely improved with use.

Something that happened to me when I first starting using mine, was that there was a A/C vent over my set up. Gave me fits until I realized what the problem was. :banghead:

might help, Good Luck

 

[razorback2003]

I put a baffle in my rcbs uniflow powder measure and it helps a lot.

 

[Clark]

Both my brother and a friend insist on putting their Uniflow powder measures back together backwards, so it meters on the up stroke.
This is just SO WRONG.

If you think it meters badly with 3031, try some 800X.

 

[ranger335v]

Without a clue how much variation you're actually getting we can't know if you really have a problem or not. ??

 

[T Bran]

When you are throwing a few charges to get the powder collum settled do not dump the powder back into the measure as this also has an effect on the collum.
I learned that one the hard way. Things got much better when I learned to dump it back in the jug.
For my rifle loads I also dump a bit lite and trickle up the remainder of the charge. Since I weigh every load it really doesnt take much more effort.

 

[helotaxi]

3031 is probably one of the more difficult powders to get a consistent throw with. A powder trickler is your friend with that one. Despite all the complaining about how poorly Varget meters, it meters like a dream compared to 3031 or 4895.

 

[jimflam]

There is a good article on powder measures in Handloader magazine #282, February 2013