Unique metering problem

[Kevin G]

DJML66,
Along with the smaller rotor and powder baffle I mentioned earlier, I neglected to mention that I disassembled my measure completely. I then gave it a good cleaning and LIGHTLY polished any spots on the rotor and frame that looked in need of it. Lightly oiled the surfaces and then wiped it off.
Whenever I switch calibers(generally about 1000rds) I go through the above procedure, usually w/the exception of the polishing.
I top off the hopper after level drops 2-3".
FYI smallest charge of Unique I routinely throw is 5.0gr +/-0.1gr.
When I switched to a progressive rig from another manufacturer, rather than use the new powder measure supplied w/the progressive outfit, I chose to stick w/my RCBS unit because I like it and probably because complete change is hard for me to accept.
Good Luck, Kevin

 

[acl864]

Like MKT I find Unique cycles through my RCBS Uniflow best if I cycle it hard with an audible clack at top and bottom of the stroke. I also add a sharp rap to the end of the handle with my index finger twice at the top and twice at the bottom. This typically gives me +/- .1 grain charges.
As Ridgway mentioned Universal Clays is a good alternative to Unique that meters much easier. I've been trying it out recently and have decided that when my stock of Unique is used up I'm switching to Universal. So far I can do anything with Universal that I can with Unique, it meters better and Hodgdon has much better data online. A side bonus is that it's not as popular as Unique and is easier to find on the store shelves right now.

 

[TSQUARED]

djml66.
I briefly used Unique when initially loading 9mm a number of years ago. I use a Dillon 550 and did not expereince the variation you described but gave up on Unque because of the lack of reliable data from Alliant. I still use Unique for loading 28 ga. shotshell but have switched to p;owderssuch as Bullsye, W-231, WST and American Selct for all my pistol loads with jacketed bullets.

 

[djml66]

ACL864, do you have the small (pistol) rotor in your Uniflow?

 

[acl864]

Originally posted by djml66:
ACL864, do you have the small (pistol) rotor in your Uniflow?

No, it has the standard rotor and no baffle- That's probably why I have to work so hard clacking and tapping to obtain a reasonable consistency in the Unique charges. I do use different techniques for different powder. For instance, Bullseye throws dead on the money all day long with nothing more than a firm steady cycle. BTW- The Uniflow I'm using was bought second-hand... in 1981. I know the cosmetics of the product have changed through the years. For one thing mine has a clear cylinder instead of green. I'm not sure if materials and manufacturing tolerances have changed since this one was made.

 

[djml66]

I'm taking to heart all the recommendations for Universal, w231,and others. And I will try these as I find them. An impediment I have to deal with is all my chrony data on dozens of loads in all my favorite calibers (.380,9mm,357sig,38spl,357mag,41mag,44mag,40s+w,and 45acp)--more than 90% of which is with Unique. I started with Unique partly because of its ubiquity---I seldom find a list of pistol loads that doesn't include Unique.

On a side note (and getting slightly off-topic), I have noticed that, fairly consistently, my 9mm and 357sig results are below published velocities, and 40s&w and bigger caliber results are above published velocities. Sometimes by quite a lot. (exception: 357mag,41mag and 44mag seem to be very close to "the book") E.g., Power Pistol load for 45acp 230FMJ from Speer 14 that should be about 803fps turns out to be 906. To keep this around the topic, Unique results are not this far off, but still in the same direction. FWIW. Another exception is that my can of Blue Dot is usually 100 fps slower on all recipes.

 

[johngalt]

I've found Unique to meter acceptably (but not perfectly) in my Hornady LNL powder measure, using the pistol rotor. When set to throw 6.3 gr, I didn't see it range more than about 6.1 to 6.4. It was more often off low than high.

 

[djml66]

Talking with you guys has really helped.

I took my Uniflow apart and looked for something to clean and polish. There were what I thought were big clumps of powder on the surface of the throat just above the drop tube. Long story, short they turned out to be jagged metal! After 20 mins with a file and a final cleaning, I put it back together and reset it to 6.0 gr (after a dozen or so throws to "prime" it). Next 10 throws were within a tenth. Huge improvement!

 

[DCC]

Had the same "Unique problem" some years ago and gave up using Unique because, also with an engineering background, didn't like the inconsistency and switched to other pistol powders.
Glad you fixed your Uniflow with a little fettling.

DCC

 

[Kevin G]

DJML66, Let us know how you make out when you install the sm rotor and baffle.
Kevin

 

[djml66]

Kevin G,

I certainly will. I am thinking about ordering a new Uniflow with the pistol rotor, plus a baffle. I can compare them side by side--and also have two different power/charge setups. --I know, I know---I have to put a sticker on them to keep from getting mixed up!

BTW, I just did a run of 50 JHP's weighing each throw. Target was 6.0. I got 3 6.1's, 2 5.9's and 1 5.8. This is much better than it was, but I will continue to measure for my JHP. It's good enough now, I think, to quit measuring for ball target ammo.

 

[stang68]

I've said this before on this forum but I use Unique exclusively with my Lee Adjustable Powder measure and have found that if I tap the side of the dispenser just before raising the ram to drop the powder I get +/- 1/10th of a grain consistently.

 

[flash60601]

For years, I have been getting less than +/- 0.1gr variation with an old, reliable
Bulllseye" powder measure manufactured by Pacific. It has the brass cylinder with a fixed charge (a hole bored to depth and ID to give exactly what I want). Unique is my friend.

But as an added goodie, I have found that disassembling the powder measure, (and I did this to my Uniflow, too) cleaning it thoroughly, polishing the cut-off surfaces, final wash with alcohol and then an application of the colloidal graphite mold-prep for blacking bullet molds makes things slick. Wowie!

The baffle in the Uniflow is polished and blackened, too.

The old Lyman #55 had a knocker on it for good reason. And it still works, though the Uniflow is easier to adjust.

Flash