Dillon 550b powder measuring Constancy?

[georgerkahn]

I am loading 110gr bullets in .38 S&W Special cases, to be propelled by 4.8 grains of Bullseye powder, using a Dillon 550b with their powder measure.
I recently read a post where OP takes now-primed, but empty case from stage #2 before powder addition; puts it on a digital scale which he zeros, and then adds the powder. Upon powder addition, he puts case back on scale -- to read actual weight of powder added.
For "kicks & giggles", I wished to load 200 of these, and tried it. While 164 dropped the precise 4.8 grains I desired, 27 dropped 4.7 gns., eight dropped 4.9 grains, and one dropped 5.0 grains.
This was an eye-opener for me, having loaded thousands in past without this step; I'd just weigh/adjust maybe first ten; then, about every 20 or so rounds, do a test dump-weigh-pour back in.
Is this the "norm"... or, might one of you learned, knowledgeable folks suggest something I may be not doing just right to cause this deviation? (I have a grounded bare copper wire through measure to A.C. ground, and have pretty much ruled out static electricity as a possible cause).
Thanks much!
geoAttachment 239548

[Sig556r]

That's my "norm" for single stage reloading but on a Dillon, just calibrate once (+ random checks) & run with it.

[Dan Cash]

Your results are normal. Some Dillon measures are more consistent with some powders than others and I don't know why. I have one measure that is all over the place with Unique yet drops bullseye with a little more consistency than yours. Go figure, just don't build a load that is 1/10th grain under a burst chamber.

[garandsrus]

Keep in mind that the digital scales are only accurate to .1 grain from what I remember so your powder drop is probably more consistent than you realize.

[Petrol & Powder]

Keep in mind that the digital scales are only accurate to .1 grain from what I remember so your powder drop is probably more consistent than you realize.

/\ YEP

And while I will not run Unique and some other difficult powders in a powder measure, I've never had a problem with Bullseye, ww231, WSF or other powders that meter well.

I've pulled cases off my 550 and weighed the powder charges at random to check the consistency. I came to the conclusion that I was worrying for no reason. After a while I just set up the powder measure and confirmed that it is dropping the correct charge weight for the first half a dozen or so cycles. When I'm satisfied that the powder measure has settled down and is throwing the desired charge weight, I rock & roll.

[Burnt Fingers]

Once I've got it set...with brass in every location I just start pulling the handle.

[M-Tecs]

I do polish and turn my measures as below. I also convert them back to the old style spring activated style. With ball powder they are incredibly repeatable after turning. With flake and stick powder they run equal to any for my Redding and Harrels measures.


https://www.24hourcampfire.com/ubbth...provement_Modi

https://skispcs.blogspot.com/2010/02...re-tuning.html

http://ashevillerifleandpistolclub.o...re-Tune-Up.pdf

https://forums.1911forum.com/showthread.php?t=154783

https://forums.brianenos.com/topic/1...n-dillon-550b/

[jmorris]

Keep in mind that the digital scales are only accurate to .1 grain from what I remember so your powder drop is probably more consistent than you realize.

Yep, some also self zero inside a certain amount of weight to cover up the fact that they drift over time as well. I would say for the amount of time it would take to weight 200 charges while your loading a “standard” to ensure the accuracy of the scale is as important as the weighing of the charges. If you have a lab scale that can weigh to the hundredth of a grain, the results would mean more to me than if you used any of the cheap hobby digital scales.

[David2011]

George, that works out to +2.06%/-2.1%. As said, you might be off less than a full tenth. Your actual variance could be as little as .06 grains. However, Alliant shows 4.6 grains as the maximum standard charge for a 110 GR Speer GDHP. If your cartridges and revolver are +P capable, the maximum charge is 5.2 grains so you're well within that load.

[ioon44]

I only weigh powder on a RCBS 505 scale, I have used several electronic scales and they can drift from zero. One key in using a 550 is to keep a consistence and smooth operation.

[MrWolf]

I've had the same issue. Ended up polishing everything and putting in two baffles. Just something I know happens and am aware. I do watch for powders that don't meter well in my 550b and plan accordingly. Good luck
Ron

[6bg6ga]

I've checked my 650 Dillon. I took my powder measure bar out and buffed it and re-installed it. I made a slight difference possibly worth the time. Unless your consistent every time your load is going to vary a little so one simply adjusts the load slightly.

[OS OK]

You take the time and have patience to carefully set the press up for an exacting charge...zero the scale with the empty case on there, put that case in the press and charge it & check it over and over until you have adjusted the throw to perfection...you think..."Ahhh, got it...now I can boogie and make a pile-O-ammo. I'll check throws ever 'so many' ''...however as many that puts your mind at ease.

With an empty shell plate, you typically put the first case in the carefully adjusted press & size it and deprime, on the down stroke the shell plate indexes as you push forward on the handle and prime...load another case & size/deprime it and push the handle forward and prime it... simultaneously the first case has been charged & production has begun, some presses may be different but it's basically as described...then we sit back and know that 'all is well in the loading shop today!'

The only problem with this is that the very first case has more than likely been over-charged by as much as .2g's, depending on powder type and throw...and...the second case is likely to have .1g too much.

But why?

Vibration on the press. That powder throw has to wait until the second crank of the press to load the first case...the press vibration has settled the powder in the metering hole of the throw.

We go along religiously checking every 'so many' cases and discover that this powder is only off by +/- .1g...and we deceive ourselves into thinking that this powder or this specific measure is the greatest to meter with...when in reality that is not the case...+/- .1g is in reality a .3g variation overall.

Some might think that loading 'at or near maximum charge' might not be a good idea? What might happen if I had to clear a minor problem during production and the press was cranked without a successive charge being thrown because I had to pull a case because I noticed a case imperfection after sizing or a primer insertion didn't feel just right and then a blank shell plate rotates under the throw without the throw delivering a successive charge....hmmmm?

Might that next case be overcharged also?

[44magLeo]

Most electronic scales display readings out to one decimal point. As in .1. If a weight falls between 0 an.1 it rounds up or down.
If you have one charge at 4.44 grs it will read it as 4.4. The next charge is at 4.46 it reads it at 4.5 grs.
The scale says the charges are .1 apart but are actually .02 apart.
This can make you think your measure is not as accurate as you think.
This is one reason I don't like electronic scales. There are others, such as drift, emi. are a few of the biggies,
I have a couple electronic scales and they are not even good enough for weighing cast bullets. The better one you can weight the same bullet 5 times and get 5 different weights.
I'll stick with my Lyman D1000 scale. It works and I trust it. I also have a Lee safety scale that works just as well. The Lee being only able to read to 100 grs limits it's usefulness.
On either one I can read the added weight of one kernel of a coarse powder such as H4350. I bit tough with fine powder.
I have serious doubts an most electronic scales can do that. There may be some that will, but most loaders can't afford them.
Leo

[OS OK]

With a trusty & reliable beam scale you can make that pesky digital scale tow the line!



Without the beam, you can verify whether or not the digital is wandering too...get a set of scale weights. You'll know instantly whether or not it's time to recalibrate.

[6bg6ga]

Some good points being made here. Good press mounting so that the press doesn't move. Not trying to load a maximum charge with any type of powder measure. You want to load maximum loads then I suggest using a powder measure set close to the max charge you desire and trickling in the rest and using a beam type scale as your final judge. So, you want maximum charges then do it the old fashoned dated way that us old folks learned that yealds the desired results without blowing your freeking head off not to mention blowing up the gun.

I recently tied to load 300 blackout on my Dillon 650 with the small powder bar with H110 like the info on the Dillon suggests for under 25 grains. Didn't work out as I was all over the place. Swapped the small powder bar for the large one and started throwing better loads. Took the powder bar out and buffed the heck out of it and ended up +- .002 grains. Occasionally I had a flyer. The charge I ended up with wasn't a max charge but close enough that a little variation wouldn't put me over the top.

People need to realize that any movement in the press or any variation as to how you run the press pressure and stroke speed will result in a different result. Want perfection then weight out every charge.

[Burnt Fingers]

You take the time and have patience to carefully set the press up for an exacting charge...zero the scale with the empty case on there, put that case in the press and charge it & check it over and over until you have adjusted the throw to perfection...you think..."Ahhh, got it...now I can boogie and make a pile-O-ammo. I'll check throws ever 'so many' ''...however as many that puts your mind at ease.

With an empty shell plate, you typically put the first case in the carefully adjusted press & size it and deprime, on the down stroke the shell plate indexes as you push forward on the handle and prime...load another case & size/deprime it and push the handle forward and prime it... simultaneously the first case has been charged & production has begun, some presses may be different but it's basically as described...then we sit back and know that 'all is well in the loading shop today!'

The only problem with this is that the very first case has more than likely been over-charged by as much as .2g's, depending on powder type and throw...and...the second case is likely to have .1g too much.

But why?

Vibration on the press. That powder throw has to wait until the second crank of the press to load the first case...the press vibration has settled the powder in the metering hole of the throw.

We go along religiously checking every 'so many' cases and discover that this powder is only off by +/- .1g...and we deceive ourselves into thinking that this powder or this specific measure is the greatest to meter with...when in reality that is not the case...+/- .1g is in reality a .3g variation overall.

Some might think that loading 'at or near maximum charge' might not be a good idea? What might happen if I had to clear a minor problem during production and the press was cranked without a successive charge being thrown because I had to pull a case because I noticed a case imperfection after sizing or a primer insertion didn't feel just right and then a blank shell plate rotates under the throw without the throw delivering a successive charge....hmmmm?

Might that next case be overcharged also?

ANY time I have a "problem" when loading on a progressive press I pull all the brass off the shell plate and start over. Cases that are charged get dumped. I will put the cases back in the seating position and the crimp position.

This prevents any problems.

[dverna]

+/- .1 grains is excellent and will produce match ammunition. Do not overthink this subject.

Weighing charges on a beam scale is time consuming and nets no improvement in accuracy or safety.

BTW, if you do not wish to spend money on check weights (as I think they are overpriced) use your beam scale to make your own. For example, my favorite load is 44 gr of Varget and I use a 50 gr bullet to check the scale. If Chargemaster weighs it to 50 gr, I do not go through the calibration routine. You can use bullets. dimes, nickels, quarters etc.

Best not to have your scale on the same bench as your press if you can. Or make a shelf attached to the wall that your scale sits on.

Some people are anal and need to weigh every charge...some use a progressive and weigh every 10-20...really no good reason to do it. I typically weigh every time I load more primers (every 100 rounds) and have never had a problem.

Maintain your cadence, keep the measure at least 1/3 full and use baffles.

If your press has an extra station, add a powder check.

KISS

[6bg6ga]

The problem seems to be getting the progressive press to throw consistant charges or charges that can be relied upon. No progressive press that I've ever run loading rifle calibers has less than a .002 gr difference thus me mentioning if they wish to throw maximum charges to do it on a single stage press. I'm not going to tell someone that is having problems throwing charges on their Dillon 550 or 650 hey go ahead maybe you'll get lucky and not blow your head off. If its throwing .001,.002,.003 difference in charges it doesn't make common sense to trust it. At least I won't. I will back the charge off a bit and check about 50 powder throws before I would even think of loading and then I personally will be checking each 10th case to see how its doing.

[6bg6ga]

I think part of the variation has to do with the movable wedge that is screwed in or out to obtain the desired charge is also capable of some slight up and down movement. Poor engineering there Dillon. When **** moves the charge isn't going to be consistant. Maybe a better powder measure would be something like the RCBS unit and I think Hornady uses a measure like that on their LNL press. Going to silicone the screw side of one of my Dillon large powder bars give it a day or two to set and throw some charges to see if glueing it down so to speak won't eliminate some of the variation.