In the front of the Accurate powder manual there are several pages which tell you what bushing is designed to drop a given amount of powder for various loaders. Always use a scale to verify the powder drop.
Your component supplier should be able to supply you with a manual.
As you probably know, Promo has the same burn speed as Red Dot, but is more dense. The starting point you're looking for is two sizes smaller than the correct MEC bushing for the same amount of Red Dot.
For example, the MEC bushing chart says a #30 bushing will drop 17.8 grains of Red Dot. If you wanted 17.8 grains of Promo, you'd start with a #28 bushing. Of course, ALWAYS confirm actual drop weights with your scale.
PS: Reloaders can find bushing charts for MEC, Hornady, and PW loaders in the RESOURCES section of Alliant powder's webpage.
You will love Promo. It is a great powder and saves you money. Shoot it just like Red Dot. For a long time there was no data in the manual for Promo. Alliant just told you to "copy" a load from the Red Dot list. They finally copied the same data from the Red Dot list in their manual and changed the name of the powder to Promo. As all of the guys are stating above, you MUST use a powder scale. You may very well need to change bushings when you change lot numbers. You need to watch this very carefully. If you load from 17.8 to 18.2 grains you will get nice consistant loads.
I use a #30 bushing on my mec with promo and let me tell you from the 26 yd line i smoke the birds no problem!I save money and no recoil at all.Try different bushings but dont use more powder if you dont need it you will be just throwing money out the window.And as far as scales go I have never used one one thing less i need to worry about,I let my scores dictate wat i need to do.It has worked very well for me,last year i went from the 23.5yd to 26yd line and the same load is smoking them the same way.
Hello There!!I good friend of mine uses promo all the time one thing he was told that because promo is a mixture of variest powder sizes it's best to shake the container the powder is in before you install it in the hoppers on your mec this will aloud a better balance of the load, and only fill up you our making for shells .Hope this will help
Almost any powder will have some fines in it, and during transportation they settle to the bottom. If you are of the fussy type it would be wise to turn the jug around and over a few times to distribute them.
The round kegs were better, you could just roll them around on the floor.
I buy a couple of cases or more at a time with the same lot number. I still check my drops before every loading session, but at least I can go through four jugs without making major adjustments. I've seen two or three bushing sizes needed to adjust from one lot to another, and sometimes it's within a few tenths of a grain. Generally, one or two bushing sizes smaller than what you use for Red Dot. What is listed in the bushing charts sometimes isn't all that close. You need to check your drops with ascale. It's usually different between a progressive or single stage loader.