Dillon 550B powder measure

Greetings,

I just bought a new Dillon 550B and I use the automatic powder feeder that comes with it.
How is the precision of that system? I thought it was quite precise but when I weight it, it has differences +-0.2 grains from loads to loads.

Is it normal? I know my balance has a +- 0.1 grain measurement imprecision, but I can't believe the issue is the balance when one load is at 5.0 and the other one is at 5.4 when the average load is at 5.2.

I set my powder measure by taking 4 loads, put them on the scale and divide by 4 the total. I do that 5 times. In theory, it should remove the imprecision and give the targetted load. Right?

Thank you

Need more info. What caliber are you loading? Using what powder? If flaring the case mouth, be sure to flare at least .010" larger than a sized, unflared case. Be sure the blue wing nut at the bottom of the failsafe return rod is tight enough. To test, push forward on the handle as if seating a primer. With the handle held forward, tighten the blue wing nut until the coil spring above it is partially compressed. Be sure the hopper starts off at least 2/3 full, throw 10-15 charges to settle the powder under the baffle before you start weighing charges.

What scale also? A +/- .1 grain accuracy can give you .2 measure to measure deviances. I use a Dillon electronic and it is an absolute squirell about air movement and static, hence the cover. Good scientific method in verifying zero and clean hands are a must.

Greetings,

"Need more info. What caliber are you loading? "
It happened with the 2 I am loading: 357mag and 45acp

"Using what powder?"
H110, Unique, #2, Blue DOT

"If flaring the case mouth, be sure to flare at least .010" larger than a sized, unflared case."
It is what I do

"Be sure the blue wing nut at the bottom of the failsafe return rod is tight enough. To test, push forward on the handle as if seating a primer. With the handle held forward, tighten the blue wing nut until the coil spring above it is partially compressed."
It is the way it is setup

"Be sure the hopper starts off at least 2/3 full, throw 10-15 charges to settle the powder under the baffle before you start weighing charges."
I did more than that to settle the powder. I also hit very gently the transparent powder tube a few times to settle the powder.

Even after 100 rounds, it does the same thing...

I shot about 100 357 mag and got no problem with this predicament.
I shot about 20 45acp and they all fededed and shot good.

Thank you

Lot of tips and tricks at this site from polishing to adding an extra return spring.

http://www.brianenos.com/forums/index.php?showforum=78

I set my powder measure by taking 4 loads, put them on the scale and divide by 4 the total. I do that 5 times. In theory, it should remove the imprecision and give the targetted load. Right?

I guess you could do that. But I would also just weight about 20 charges in a row and see what the actual number is the bulk of them come to. I think you will see that most will be the same number with a few +/- .1 -.2 grains. Also, you might get a slightly higher number when you are sizing and dropping powder since the extra movement might help settle the powder in the bar before dropping. That and stay away from stick powders. Its not the balance, the Dillon is for turning out a quantity with great quality, but not match grade.

Make sure you are using the correct powder bar. There is one for rifle loads where you would normally be throwing larger amounts of powder and one for pistol loads where the powder charge is lower. If you are using the large powder bar and are trying to measure out powder charges for pistol loads it will not be very precise and will act just as you described. I always throw at least five charges after a new setup to stabilize the powder measure. That method has always worked for me.

Try not using the powder measure failsafe bar, and use the spring around the resevoir/powder bar method. It makes the measure operate much smoother and more positively.

I"ve had my dillon for years and the measure has been less than perfect for that many years.For my kind of shooting it is acceptable.

Operate the press smoothly and repeatably. The wanderings of the needle on your scale have virtually nothing to do with how your target will look.

People that are obsessive about powder charge variations haven't gone through the trouble to check whether it actually matters or not.

If you are getting +-.2 grain then that may be the best that you can do. Some powders meter better than others and I don’t think any powder measure is ever dead on accurate. If you want dead on accuracy then you will have to weigh each charge. I have one powder measure that will throw Titegroup within .1. Titegroup meters better than Unique. I know. I’ve used both a lot. .2 just ain't gonna make much difference at the range.

That's about what I've found setting up my new 550. Since this is the first time I have used it I was pretty anal about measuring before loading and randomly during loading.

I'm loading .40 S&W with 180 grain lead bullet and Unique. I found that I was between 5.3 and 5.5 grains. Most of my readings were 5.3 to 5.4. I am just using a cheap Frankford Arsenal digital (with FRESH batteries) to verify my charges but this guy is pretty dead on, my check weights read dead on from 1 grain to 10 grains (never tried any higher).

Since I'm shooting .40 I don't really like to get that close to the max load (in the Lee manual anyway) but even if I go up to 5.6 or so I think I'll be OK since I've got a fully supported chamber and the velocity of that load isn't exactly on the top of the .40 pressure scales.

That's my biggest issue with my press, I'm happy with the priming system and the general functionality and ease of use of it. I will try out the little tuning tricks that was linked to though...

Sigma, I’ve found that Unique doesn’t meter as well as some other powders. You may get better results with a different powder. Unique is dirtier than some other powders too. I’m using a Lee Auto Disk Pro and it does a lot better with Titegroup than it does with Unique. I’ve got a pound of WSF that I want to try but I haven’t yet. I’ll be setting up my Dillon measure for the first time today or tomorrow. I’ll see how it does. Your results are exactly what I got with Unique, about .2 gr difference.