RCBS Uniflow accuracy?

[Lumber_Jack]

What kind of accuracy should I expect from the RCBS Uniflow Powder Measure?

I set it up with WC842 and dialed it to throw 26 gr then I threw 10 charges and it weighed 262 gr. Seems good, but should I expect less accuracy or more, per charge?

I just wanna stay safe. I'm not using 26 grains per say, just used that number to test with.

[Lumber_Jack]

Ok so I threw 10 more and got 262 again. That's pretty good.

Check a couple singles got

26.1
26.0
26.0
25.7
26.0
26.0


So I guess I answered my own question. I did notice with the outlier, that I kind of dropped it with my purse. Didn't get a tap and the top and at the bottom. So If I use a consistent lever stroke it should be accurate.

[Raoul]

I use one. They are fairly accurate, It seems the variance is no more than .2 gr either way at most. More so with a flake powder such as Unique.

I suggest keeping the hopper about 1/2 full. When you add powder go ahead and throw some powder a few times before you actually start charging cases.

[Raoul]

Consistent stroke is best. Edited March 23, 2013 by Raoul

[MarkInNashville]

I had a very difficult time getting my Uniflow setup using Unique powder. Once I finally got it sat I experienced the same type of results you did. It is necessary to have a consistent throw. When I switched to Titegroup powder it was much (MUCH) easier to for the initial setup but doesn't change the consistency required.

[chances R]

It all looks good, based on your numbers.  IMO it does vary a little with the hopper level, and vibration being the biggest influence.  I would accept what you are getting, especially with that size of charge.

[tnhawk]

I've been using Unique with the uniflow powder measure and have gotten consistant results.  I try to keep the level 50 - 75%.

[Lumber_Jack]

Thanks for the tips guys. All the info seems to be consistent.

• use a constant stroke
• keep the hopper full at least halfway
• run .5lb powder through before starting to measure

[Romad7]

Good info, I have one coming with my Rockchucker. Thanks!

[Dolomite_supafly]

Do you have a baffle in your hopper?

 

If not you need to add one. It will make it very, very consistent.

 

I will take a pill bottle that fits inside and rests on the cone at the bottom. Then I will cut the bottom off the pill bottle then I dril a 1/4" hole somewhere along the side. The powder flows through the hole but stops once the powder level reaches the hole. This means a set amount of weight is always on the measure itself regardless of how much powder is in the hopper.

 

Dolomite

[Lumber_Jack]

No I don't have a baffle but I will either make one like you said, or pick one up

[RED333]

Dolomite can you post a pic of the pill bottle for us slow people? I just cant seem to wrap my brain around it.

I use the same measure, and get the same diff in weights.

[MarkInNashville]

Something I forgot to say: I was using my Uniflow at about 6 grains (and don't know if the amount matters to the results. Also after reading what Dolomite_supafly said my Uniflow does not have any sort of baffle in it. I am now using a Hornady on my progressive press and it does have a baffle plate. It makes good sense to have one (the Hornady, which is very similar, has one).

[frankmako]

i used one for 30 plus years and before that i used and still have a old texas star one.  they stay in the ball park and don't vary much.  when they do vary it is not that big and you can not tell any different when you chronograph the load.  some powders flow better than others.  same as in the dillon powder drop.  i get my weight set and lock it down.  i check it every once in a while while reloading, but i don't get wrapped around the axle when it is a little high/low during a check.  

[Guest 270win]

I put a baffle in mine and it helps with consistency.