Margin of error

[attila787]

I'm using the rcbs powder measure uniflow. While reloading some .223 using 23.5 gr. it was a bit frustrating every time I would weigh the charge released from the dispenser it would be off by .2/.5 +- Having my loads ranging from 23.5-24.0.

I had to correct at least every other load. I checked my digital scale by measuring other items and it read accurately so I know its not the scale.

So how much margin of error do you guys allow.

[IllinoisCoyoteHunter]

.00000000001 grain. I am die-hard!

Really it depends on the load. Smaller cases will generally be less forgiving. 9mm is less forgiving than 45 acp. When loading 9mm I like ot be +/- .1 grains. When loading 45 acp, +/-.2 grains wouldnt bother me, but I am usually +/- .1 grains.

If it bothers you, try a different type of powder. Some powders meter better than others. Good luck!

[PCJim]

The "rhythm" that you use when dispensing the powder could give you some of the variance. Your method of operation must be consistant.

When using the single stage press, I us my old powder throw (unknown manufacture) and have found that if I bump the handle twice at the up stroke and twice at the down stroke, it greatly helps to get more consistant loads. And like ICH stated, some powders just meter better than others.

[Christchild]

As the previous members have stated, 0.2 to 0.5 grains variation that You're getting can be the result of several, already stated variables, and if You're not striving for all-out, utmost accuracy, then You should be fine, even with SD loads with "that much" variation. Striving for accuracy, weigh each charge, don't use a powder measure. General rule of thumb, if You can achieve powder charges within (or less than) 0.10 grains, You'll never see a difference.

[amamnn]

This is why tricklers were invented---and digital dispensers................

[micksis86]

does winchester powder meter well? i'm talking specifically about 296.

[IllinoisCoyoteHunter]

296/H110 Meters ok. Very fine powder so if you have a cheaper dispenser with looser tolerances it will leak a little. I have found that when using it to load 357 mag thru my pro auto disk (cheap lee power dispenser) I get +/- .2 grains.

[Uncle Buck]

I had the same problems. After talking with the RCBS Customer Service people we figured out I was doing three things wrong.

1. Using the wrong drop tube. The little green tube that screws into the bottom of the dispenser. It caused the powder to clog if I was using the small tube and flaked powder. Went to the larger tube and no more clogging.

2. There is a locking nut (ring) on the back of the powder measure. Use it. Once you have your load dialed in, lock that sucker as tight as you can. I did not tighten the locking ring and it was causing the adjustment screw to move, or creep, ever so little and throwing my loads off kilter.

3. Swinging the lever of the powder measure has to be consistent. Do not be timid when moving the lever from an up to down or down to up position. If I am in my reloading room working on rounds, and the door is open, my wife can hear me moving the lever up and down. (annoys the heck out of her and she either closes my door or goes to the bedroom so she does not have to hear it.) Snap it up sharply and bring it down sharply. You want to do it consistently and with enough force that it allows the powder in the hopper to fall.


Also, you may need a baffle for inside the hopper. The baffle will stop the powder from bridging and preventing itself from actually filling the measure.

I am assuming you took the entire piece of equipment apart before using and cleaned it per instructions. Also assuming you have run some powder through it before. After you adjust the measure screw, throw at least ten cycles on the lever and then measure the eleventh charge.

Best of luck.

[attila787]

Uncle Buck thanks for your suggestions I will run through all of them tonight.

[lemming303]

On extruded powders I measure every load with a trickler. On ball powders, such as H110 I can usually get the thrower to throw consistently. I always test it for about 20 throws to make sure it is throwing consistently, and then still check every 5th cartridge to make sure that is still right. I also keep the tube full of powder to help it push the powder down into the the cam.