Home Forums Hunting & Shooting Ask The Gunwriters uniflow powder measure bridging

i set up a uniflow powder measure with the case activated linkage kit.....i am using 39 grains of imr 4350.... i am having a heck of a time with the powder drop bridging and throwing inconsistent loads... i have tried varying handle speed etc to combat it..... i have a cheap lee powder measure that did not have this problem......any ideas or thoughts as to why this may be happening?.....thank you

baffle installed low in the tube, settling 'taps' and a slow, controlled dump...

thanks... ill try that

There's your solution

Might look at the insert screwed in the bottom of the measure.

I had that happen some till i changed it out for the larger one.

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Might try wiping the inside of the powder reservoir with a fabric softener sheet to knock out he static electricity

The baffle was a good fix however, there is nothing on the case activated linkage kit that screws into the bottom of the measure, i.e the green adapter tubes.



The only thing that moves inside is the sliding powder sleeve of which 3 are supplied. Took the place of the old piggyback/ ammo master progressive powder feed linkage system.



If you put those green screw in adapters to the measure, it pucks it all up

Just like the green tubes that screw into the bottom, my set up for my 4X4 has different tubes that slide into the adapter for the Uniflow for various cartridges. They are different inside diameter to seal up different caliber cartridges. You may want to check and see if there is one with a larger diameter that won't bridge. I only use my 4X4 for large volume loading and since long extruded powders don't meter accurately enough for my tastes, I avoid the likes of 4831 and 4350 on a progressive and only use those powders where I can weigh every charge and trickle.

As hard as cycling the Uniflow with 4350 can be,
I'd be amazed to watch that mechanism run it.
Well.

But I'm armchairing, based on manually using one for
the 4350s and 4831s.

A good, strong, well designed ,mechanical one should be
able to run smoother than a person.

Lot of qualifiers in that sentence.

Dillon for high production. Charge master for single stage. Back in the day, if low producton, A uniflow mounted solidly and a good thump with each up and down stroke. For pistol production back in the day, a lil dandy with a bunch of rotors. Took all evening to load a box of .357s. Yeah I know, an old man reminiscing and not addressing the question. All the above suggestions.I've used and work well.

No sir you aren’t armchairing. Basically correct. The purpose of that basic system was handgun rounds and small rifle rounds the largest being 223.
The original design was even weaker but worked the same. The powder drops out of the drum into the tube holding the sliding sleeve, the sleeve being tapered like a funnel would allow the powder to kinda swirl for better flow into the case. If you use the green inserts then you are restricting the drop and trying to push the charge directly into the sleeve, which tends to cause bridging, or inconsistent drops with lots of powders.
Never did like the Uniflow for any stick powder which is why it permanently resides on a piggyback and I have a better measure for rifle. This in itself doesn’t bother me as I never load rifle on a progressive. Don’t believe in it.

Anyway original 1990 design of RCBS case activated powder drop.

If you want to avoid bridging don`t use IMR stick powders.Go with the new Enduron,Ramshot,Winchester,Hodgdon powders.Even the Shooters World stuff is pretty good and meters very good.Older IMR powders give some great accuracy such as IMR 4350 in my 257 Rob AI seems to out shoot every thing else,but I run that through my RCBS Chargemaster that does not care about the powder length.Just sayin ,you are causing you own problems here by your powder and equipment choice.

Exactly 👍