Uniflow powder measure and small charges of Bullseye

[Richard.Howe]

I bought the RCBS Rockchucker Supreme kit some time ago.

The Uniflow powder measure was included. This measure threw very repeatable and accurate charges of H4831 for my 300 Winnie, but it seems to be very inaccurate with small charges of flake type powder.

I discovered this while loading target .357 HBWC loads in the range of 3.5 gr Bullseye. The throw cylinder frequently acted like it got clogged or had to cut powder to finish the throw. Powder throw varied as much as 0.5-0.7 grains...my velocities were all over the place when I got to the range. This could be a serious shortcoming when experimenting at the upper end of recommended loads.

Now, short of a powder trickler, is there a better way to meter this kind of charge?

Help!

Thanks,
Rich

 

[Black Snowman]

I have a Uniflow also and have noticed it doesn't like the flake powders as well. If you are throwing small charges use the pistol chamber if you have it. It helps somewhat.

The best thrower I've found for large flake and flattened ball powders is actually the Lee Auto-Disk Deluxe. Even the huge flakes of the old AA #7 meter pretty consistantly. No more than +- .2 gr and usually only +- .1 even on a small charge for 9mm.

For long extruded powders I've had the best luck with the Lee Perfect powder measure. Don't try fine ball powders in this thing though. Mine leaked terribly with them.

 

[Jim Watson]

I never could get a Redding to deliver Bullseye like I thought it should, either. Never bought another can of Bullseye, although I keep a little for comparison loads; if a pistol caliber has ever been loaded with smokeless, it has been loaded with Bull.

You can change measures or change to Ball powder.
I have shot a lot of Win 231 and 452AA (No longer made, try WST), HS6, and some AA #2, most out of Dillon and C-H measures but some from an RCBS Unifl with small drum and micrometer adjustmen with little trouble from any of them.

 

[lee n. field]

Do you have the large measure cylinder assy., or the small one?

I had the same problem, and asked here last year sometime. Somebody clued me in to the fact that RCBS had two different cylinders.

IIRC, 3.5 grains of bullseye is about where the large cylinder bottoms out.

 

[candt]

I have noticed the same thing with my uniflow and Unique. It doesnt vary quite as much, but its not as accurate as with AA#5. The #5 is dead on every time. I load 9mm, and .45 acp with this. Makes it a joy to throw charges for me.

 

[Standing Wolf]

I'm in the process of switching to Tight Group from Bullseye: it's easier to meter small charges consistently, and it gives me greater consistency on the range.

I use a Lee powder measure with discs. It's reasonably accurate with Bullseye, but weighed charges vary as much as two tenths of a grain. The same discs give me about a tenth of a grain variation with Tight Group.

 

[stans]

My Uniflow does the same thing with small charges of flake powders. The larger the flake size, the worse the problem. If you want to use flake pistol powders, you probably should get the drum with the small diameter powder well.

 

[Dave R]

I use an old Uniflow with the small drum with Unique powder. Pretty big flakes. Throws 4-6 grain charges very consistently.

 

[burrhead]

I’ve been using the same Uniflow for 25+ years. Four grains of Bullseye is what I use for both 45 ACP and 38 Special. Loaded a zillion of 'em. With the small drum it stays within +/- 0.1 gr.

I guess your mileage varies.

 

[bfoster]

I'm able to hold charges of Bullseye in the 2.5-5 grain range within ±0.03 grains at worst with my old California made Saeco measures when using the smaller of the two drum sizes.

For smaller charges (down to 0.8 grains, as is used for 25 ACP) I use an old Ideal #5 measure or a current Lyman #55. In this range, these measures can be expected to hold ±0.06 grains, proportionately quite a bit, but there's nothing better that I've found.

Bob