Powder Variations with the 550B

[callahan318]

I was loading my first pistol rounds and my variation of powder was off by .2 grains.

This occured when I pulled the handle fast and slow. Is this normal?

[BigDog[RE]]

I was loading my first pistol rounds and my variation of powder was off by .2 grains.

This occured when I pulled the handle fast and slow. Is this normal?


What powder? With unique I see .1 variances, with WSF its dead on everytime.

I find that Unique (and other flake type powders) flow better if you wipe the hopper down first with a dryer sheet, that helps kill static cling. I also find that keeping the powder measure full delivers more consistent results.

[callahan318]

This is with Blue Dot...

[DssG19]

;11962']What powder? With unique I see .1 variances, with WSF its dead on everytime.

+1 with WSF, it's amazing how accurate it drops.

[Vulcanese]

This is with Blue Dot...

Blue Dot does not meter as uniformly as some powders. A variance of 0.2gr is not that bad.

[callahan318]

How bad of a variance can occur with Blue Dot?

[Vulcanese]

How bad of a variance can occur with Blue Dot?

I did some RL550B meter uniformity tests a few years ago because I was curious about how accurately this particular press would throw powder charges.

I charged a case 100 times without adjusting the powder bar, and weighed each charge with a Dillon digital scale. Following are the results, listed in order from best metering to worst:

Powder: Winchester 231
Highest: 5.1
Lowest: 4.8
Average charge weight (out of 100): 4.94
Range (highest minus lowest): 0.3 = plus or minus 0.15gr (great!)
Std Dev: 0.082

Powder: Hodgdon Longshot
Highest: 10.3
Lowest: 9.8
Average: 10.068
Range: 0.5 = plus or minus 0.25gr (not so bad)
Std Dev: 0.108

Powder: Alliant Blue Dot
Highest: 9.3
Lowest: 8.6
Average: 8.917
Range: 0.7 = plus or minus 0.35gr (not as good)
Std Dev: 0.124

Powder: IMR 800X
Highest: 9.2
Lowest: 7.9
Average: 8.50
Range: 1.3!! = plus or minus 0.65gr (not good at all)
Std Dev: .209


So to answer your question about Blue Dot, for the 100 consecutive charges that I measured, the range was 0.7gr, so that's plus or minus ~0.35gr. Obviously, the larger the desired powder charge, the less critical a 1/3gr variance will be.

[DssG19]

I did some RL550B meter uniformity tests a few years ago because I was curious about how accurately this particular press would throw powder charges.

I charged a case 100 times with out adjusting the powder bar, and weighed each charge with a Dillon digital scale. Following are the results, listed in order from best metering to worst:

Powder: Winchester 231
Highest: 5.1
Lowest: 4.8
Average charge weight (out of 100): 4.94
Range (highest minus lowest): 0.3
Std Dev: 0.082

Powder: Hodgdon Longshot
Highest: 10.3
Lowest: 9.8
Average: 10.068
Range: 0.5
Std Dev: 0.108

Powder: Alliant Blue Dot
Highest: 9.3
Lowest: 8.6
Average: 8.917
Range: 0.7
Std Dev: 0.124

Powder: IMR 800X
Highest: 9.2
Lowest: 7.9
Average: 8.50
Range: 1.3!!
Std Dev: .209


So to answer your question about Blue Dot, for the 100 consecutive charges that I measured, the range was 0.7gr, so that's plus or minus ~3.5gr.

You better send that powder measure in to get checked, thats worse that my LnL AP powder measure.

[Vulcanese]

You better send that powder measure in to get checked, thats worse that my LnL AP powder measure.

Keep in mind that 3 of the 4 powders represented are not going to meter as well as the ball powder W231.

The 231 has a variance of +-.15gr, which is acceptable to me. I usually load 5.0gr of this powder at a time, so we are talking about accuracy of +- 3%. The flake powders can be expected to meter less consistently through any measure.

I concluded that the 550's system is close enough for me, at least for most of the powders that I use. I do NOT use it for 800X. The variance is much too great, and this is to be expected since it is comprised of huge flakes. 800X must be hand weighed.

[Steve Koski]

You better send that powder measure in to get checked, thats worse that my LnL AP powder measure.
How do you know? Have you done a 100 round test yet?

Post your results!

[DssG19]

How do you know? Have you done a 100 round test yet?

Post your results!

:dita:

Off by as much as 1.3 grs seems kinda high, .5 or higher on two others. I would'nt feel comfortable loading with that kind of range.

[fredj338]

0.2gr is not that bad for BlueDot, it doesn't meter that well. Make sure your powder return rod is tightened up so it returns the slide fully forward on the upstroke.

[BigDog[RE]]

Also, make sure that your press is mounted firmly to a solid and secure bench. If your bench isn't solid, that can cause powder issues.

[BigDog[RE]]

I did some RL550B meter uniformity tests a few years ago because I was curious about how accurately this particular press would throw powder charges.

I charged a case 100 times without adjusting the powder bar, and weighed each charge with a Dillon digital scale. Following are the results, listed in order from best metering to worst:

Powder: Winchester 231
Highest: 5.1
Lowest: 4.8
Average charge weight (out of 100): 4.94
Range (highest minus lowest): 0.3 = plus or minus 0.15gr (great!)
Std Dev: 0.082

Powder: Hodgdon Longshot
Highest: 10.3
Lowest: 9.8
Average: 10.068
Range: 0.5 = plus or minus 0.25gr (not so bad)
Std Dev: 0.108

Powder: Alliant Blue Dot
Highest: 9.3
Lowest: 8.6
Average: 8.917
Range: 0.7 = plus or minus 0.35gr (not as good)
Std Dev: 0.124

Powder: IMR 800X
Highest: 9.2
Lowest: 7.9
Average: 8.50
Range: 1.3!! = plus or minus 0.65gr (not good at all)
Std Dev: .209


So to answer your question about Blue Dot, for the 100 consecutive charges that I measured, the range was 0.7gr, so that's plus or minus ~3.5gr.

Wow, the most I ever tried was 20 rounds of unique. It measured with .1gr everytime.

[Phunahm]

Using Green Dot I ran into the same however when you drop 10 or more and avg. it its really not bad at all....Now the HS6 I used was dead on after avg. 10 drops......I thing the Dillon Powder measure is very accurate....theres to many variables with the powder shape,humidity,etc.. you need to consider..:yesnod:

[creophus]

Callahan, could it be your scale?

[Phunahm]

Callahan, could it be your scale? +1 Good question

[Steve Koski]

Come on, you guys have powder measures, and scales. Do a test like Vulc did and stop your bitching.

[callahan318]

I could very well be the scale I suppose. I finally got it figured out after a bit of work. It is set at 8.1 grains, and flucuates all the way to 8.3 grains.

[Mogollon]

Keep in mind that powder scales are accurate to +/-.1 grain.
My experience is that in handgun-sized charge weights, ball and tiny flake powders such as Bullseye will consistantly throw within +/- .1 grain. Medium flake powders such as Red Dot and Blue Dot will mostly be within +/- .1 grain, with the random +/- .2 grain powder charge. Big flake powders such as Unique will go +/- .2 grain regularly.:blues:

[DssG19]

Keep in mind that powder scales are accurate to +/-.1 grain.
My experience is that in handgun-sized charge weights, ball and tiny flake powders such as Bullseye will consistantly throw within +/- .1 grain. Medium flake powders such as Red Dot and Blue Dot will mostly be within +/- .1 grain, with the random +/- .2 grain powder charge. Big flake powders such as Unique will go +/- .2 grain regularly.:blues:

Mongollon you seem to have the most knowledge here in reguards to the 550. Should the powder measure be off 1.3grs with any powder? My powder measure throws 5.0 of WSF 10/10 times. Never gone as far as a 100. If it's off +/- .2, I'm good with that. I never load anything to the max anyway.

[Mogollon]

Adjusted correctly, no brand of powder measure should be more than .3-.4 grains off with the coarsest extruded rifle powder for charges up to about 60 grains in weight.:thumbsup: