Inconsistent powder charges in Dillon 450

[CollinLeon]

I've been using Alliant Red Dot as a powder and loading some 13gr loads for my .45-70. I noticed a bit too much variance in my velocities after I chronoed them today, so I weighed a few powder charges from my Dillon powder measure.

Out of 16 charges, I found that they varied from 12.7 gr to 13.5 gr, with an average of 12.97 gr and a standard deviation of 0.23.

It seems that if the press is bumped a bit, the powder drops heavier, but if I just drop one powder charge after another, they are lighter. My reloading bench is made from 2x8s joined together, so it's rather stable, but there's still a bit of movement in the press itself when I'm reloading and I'm thinking that this is causing the powder to be charged higher than when I do the initial powder measure setting.

I've also heard that Red Dot does not meter well with the Dillon powder measure, but some other powders do.

Has anyone had similar experiences?

[Forrest r]

Try a powder baffle or 2 or 3.

http://smith-wessonforum.com/attachment.php?attachmentid=34701&d=1294716562

[Alvarez Kelly]

Are you using the original Dillon 450 manually operated powder measure or a newer case activated powder measure?

[CollinLeon]

Are you using the original Dillon 450 manually operated powder measure or a newer case activated powder measure?

The original manually operated one.

[Alvarez Kelly]

First, I have never loaded with Red Dot. If it is not a long grain, extruded or stick powder, it can meter well in any Dillon powder measure.

Does your powder hopper have the factory installed baffle? If not, you must get one before going any farther. Even with a baffle, it will still take about 10 charges to "settle down." Since YOU are the opening and closing "mechanism," it is critical that you pull the handle and allow it return in the exact same way every time. The only way to develop that skill is sheer repetition. As you noted, any extra movement, banging, or jaring may result in a heavier load.

I would charge a small container of some kind 10 times, carefully trying to do it the same way every time. Dump the powder back in the top of the powder measure, then dump 10 more charges. What is the weight of the second group of10 charges? Then dump one more charge in a case and weigh the charge. Does it weigh within .1 gr of the 10 pull average? If so, you are there.

I would repeat this everytime you start a new loading session. It takes about 10 throws for the Dillon measures to settle down and throw repeatable charges.

At least with mine, and just about everyone I have talked to.

Good luck! Let us know how it works for you.

[Longwood]

The original manually operated one.

I learned years ago while shooting competitively to "Bump" my measures. I did it first with my RCBS Uniflow, then with my Dillon 450 manual measure and I still do it today with my Loadmaster with a manual measure in place of the inconsistent one that came with it.

I learned to move the slides or rotors to each position rather sharply, back up a bit, then lightly but sharply, bumping the stop again gives much more consistent loads than a gentle sliding or turning motion.

I have heard of people putting vibrators on their progressive press measures to get better flow and fill-out of the measuring cavity.

[dillonhelp]

Be sure to start with the powder hopper at least 2/3 full. Throw 10-15 charges and dump them back to settle the powder under the baffle, then begin weighing. Red Dot is a somewhat coarse flake powder; expect most charges to be within +/- .1 rain, with the occasional +/- .2 grain variation. I use Red Dot in most of my handguns, feel it is a bit fast for a rifle load.

[wv109323]

I have just evaluated my Dillon Powder measure for accuracy. I have a 550 with the activated powder measure but I have the 450 manually operated measure as well.
I evaluated using 43.0 gn. of WW748 to load Sierra 168 for a M1A with the large powder slide. I found that if I rocked the powder measure loads would vary 1.5 grains. I wanted to make sure that you could not throw a partial charge after throwing a normal charge by moving the powder slide.
The best I could get doing everything consistently is +/- .2 grains.
With the price of Sierra's 168 Matchking I will trickle all powder charges instead of throwing them out of a powder measure.
Also you can help yourself by tapping on the powder measure to "compact"the powder before you start to weigh charges.

[CollinLeon]

Does your powder hopper have the factory installed baffle?

Yes, it does have the factory installed baffle.

[Alvarez Kelly]

Yes, it does have the factory installed baffle.

Good. Did you follow the rest of the advice? Dillonhelp basically said the same thing I did. Throw ten charges to get everything settled down, then check it.