Powder Measure baffle

C

cdoc42

New member
There was a discussion in the past about baffles to maintain the same level or density of powder in the measure column for drop consistency and Unclenick shared a detailed plan whereby we could make our own.

I happened to come cross this idea as I loaded up .38 Specials and 9mm Luger rounds and I wondered what the opinion might be as to the comparability of effectiveness.

I have a Redding Powder Dispenser that has an approximately 6.25 inch powder reservoir. I have a wide-mouth household hard plastic funnel with a 2-inch drop tube that I thoroughly coated with graphite powder. If I put about 4.5 inches of powder into the reservoir, place the funnel on top and fill it about a third full, the drop tube sits slightly inside the powder column and that position is maintained as I crank out my loads as long as I keep sufficient powder in the funnel.

I have the impression this is essentially what the baffles that were previously discussed do. Am I wrong?
 
While running out of powder during a weather related loading marathon, I checked if the baffle made any difference in my RCBS Uniflow powder measure.

I was running out of whichever powder I was using. I ran the powder below the baffle and weighed EVERY charge. The measured load never varied until there was not enough powder to fill the chamber in the powder measure.

Do your own test and travel at your own risk. I still use the baffle and refill at 1/2.
 
I’ve seen this proposed before and I’m still not buying it. What the baffle does is maintain a constant height of the powder column directly above the PM cylinder. Theoretically, this keeps constant pressure on the powder flowing into the cylinder because, while the powder column above the baffle is growing smaller and smaller with each charge of powder into the cylinder, the column below the baffle remains fairly constant. The powder above the baffle presses down on the baffle but not on the powder in the cylinder, thereby not compressing the powder in the cylinder as it would without a baffle. So, the purpose of a baffle is to keep a constant level of powder impinging on the cylinder.

If you use a funnel as described by the OP, you're actually not accomplishing the same thing. The column of powder pressing down on the charge is as high as the powder in the hopper plus the powder in the funnel. The overall height of the effective powder column is higher with the funnel than without and it decreases faster than it would without the funnel.

Whether baffles are effective or not depends on who’s telling the story. ymmv
 
I have Uncle Nicks baffles in some of my measures, and some identical measures without them and have found no difference. These are Lee measures that use the replaceable rotors, both manual and the automatic type. I think their design on the powder reservoir eliminates the problem. Just my limited experience with my particular equipment.
 
It does seem to help when using a very light, bulky powder such as PB or the like.
Long grain stick powders seem to jamb the rotor less if the baffle is used, but it may be just wishful thinking.
The difference in thrown charge weights is so slight unless you are shooting bench rest matches, it really is not needed.
 
I've updated this do-it-yourself baffle template set several times over the years. There are some at the end for specific brands of powder hopper.

Baffle Template File

Jetinterior guy's experience does not match mine, but you need to know the beneficial applications. The baffles help unbaffled drum measures like the Uniflow and BR30 most. Adding a single baffle to an already-baffled measure like the Perfect or the Dillon is like adding another stage to an RC audio filter: it makes less difference, but can get you past a hump with some powders. In general, the baffles seem to do little for spherical powders, as they are incapable of packing to much higher density. It is with stick powder, especially long-grain stick powders, like 4064, that they seem to help most.
 
I have two Uniflows, one with an "official" RCBS baffle. I can't measure a difference using Accurate #2 & #5 in 32L & 38. I was expecting to see something...weight, consistency, whatever, but it didn't happen. I played with different baffle heights and still no difference. Must be the ball powder as noted already.
 
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