Going digital ...

[jski]

Got tired of the laborious efforts required weighing using the ol' pan scales. So, after much online research, I bought a GemPro 250 digital scale to make my life simpler ... or so I thought. The GemPro out-of-the-box experience was what I had hope for ... simple. I plugged it in, easily calibrated the scale, and was up and running.

Weighed some bullets and got the values I expected. Weighed a small weight of precisely known value ... dead on. All was good.

Then I started weighing powder charges thrown by my RCBS powder dispenser. Adjusted the settings to where I thought I needed to be, locked down the dispenser, and did something I had never done before ... I started randomly weighing charges during my reloading.

To my chagrin, they differed by as much as .3 grains. I put the precise weight back on the scale ... dead on. I re-weighed some of the aforementioned bullets ... good.

So is it the GemPro or my RCBS powder dispenser?

[cw308]

I have been using the RCBS ChargeMaster 1500 for 25 + years . Read some articles on the GemPro 250 , I ordered one . What I'm getting is , my loads from my 1500 are off . The 250 is very sensitive , I use two pans , one for each scale . I take the powder from the 1500 pan and pour it into the 250 pan .

The powder going into the 250 is most of the time off from the 1500 , I will lift the pan slightly on the 250 to reweigh , its very sensitive , your dealing in hundreds of a grain . I'm using IMR 4064 for my 308 , it will pick up one grain difference . Takes time to get use to .

If you want to be exact , its the way to go.

[444]

"So is it the GemPro or my RCBS powder dispenser?"

It's definitely the powder dispenser. I can say that with complete confidence. If you randomly weigh powder charges on ANY scale, you will see that if you are just dropping powder charges from a powder measure that the charges vary by a couple tenths of a grain. At one point I even bought a Harrell powder measure to try to minimize the variation and it doesn't really seem much better, if any better, than my RCBS. 20 years ago, when I was using a balance beam scale I knew that my powder measure was dropping charges that varied by a couple tenths of a grain. Even today when I am using a Lyman digital powder measure where it meters out a charge onto a scale, the charges it meters vary at times by two tenths of a grain.

The real question is, does this matter ?
Well, maybe, maybe not.
If you are loading a charge that is RIGHT at max, then going a few tenths over isn't a good thing. It probably won't cause your gun to explode, but it isn't a good thing.
If you are loading pistol ammo it probably doesn't matter.
If you used ladder testing or optimal charge weight testing to develop a rifle load, it probably doesn't matter.
If you are loading .300 Blackout subsonics and shooting them at 200 yards, it will definitely matter.

Basically you have to decide, based on the actual purpose you are loading for, and based on the results you are getting, whether or not this is even an issue.

When I load rifle ammo, I do everything I know of to make the ammo as consistent as possible. And this includes weighing each powder charge to within one tenth of a grain. In reality I don't think this is a huge factor, but it makes me feel better. With handgun ammo, I don't care at all that the powder charge varies by a couple tenths of a grain. I will never be able to tell the difference.

[Nathan]

Typically powder dispensers are +/- .1 per the specs. I could believe that to be closer to +/-0.3 total spread. That is because +/-0.1 can really be +/-0.149, right?

[Don P]

Personally I do not see 3/10th of a grain being problematic. I load just handgun loads and use Titegroup which some people thinks can be catastrophic with regards to a few tenths of a grain over charge. If you are NOT loading at maximum charge weight you are good to go. To answer your question it is your powder dispenser.

[cw308]

I would agree when shooting handguns tenth of a grain no big deal . It's hard to get a one hole group of 5 . Bench rest a one hole group is possible , so making everything as close to exact does make a difference. I'm shooting 200 yard zero , every round is checked at every step if not it will show on paper.

[RC20]

What kind of powder dispenser?

Electronic , or mechanical?

[hounddawg]

I have a RCBS Chargemaster, a 750 Rangemaster, and a 502 balance beam. When weighing a charge the Chargemaster and Rangemaster agree with each other time after time. The 502 will be off by .2 no matter how many times I calibrate and zero the electronic scales. Never have figured that one out, and my suspicion is the beam scales pan or cradle has something to do with it.

Like most things in this sport as long as the charge is the same every time I am happy, repeat ability is key

[higgite]

I'm guessing that OP's RCBS powder dispenser is a Uniflow, not a Chargemaster, since he said he has gone digital and now uses a GemPro instead of a pan scale. Since there is no history of random measuring with the pan scale, the test to see if the problem is the powder measure or the new scale is to weigh random charges with the GemPro AND the pan scale. I'm betting on the powder measure being inconsistent with whatever particular powder the OP is using. For some reason, I get up to a +/-.2gr spread with Universal in my Uniflow, but always less than a +/-.1gr spread with W231.

[BumbleBug]

Originally Posted by higgite

I'm guessing that OP's RCBS powder dispenser is a Uniflow, not a Chargemaster, since he said he has gone digital and now uses a GemPro instead of a pan scale. Since there is no history of random measuring with the pan scale, the test to see if the problem is the powder measure or the new scale is to weigh random charges with the GemPro AND the pan scale. I'm betting on the powder measure being inconsistent with whatever particular powder the OP is using. For some reason, I get up to a +/-.2gr spread with Universal in my Uniflow, but always less than a +/-.1gr spread with W231.

I agree that the OP is probably talking about a Uniflow mechanical powder measure. The accuracy is dependent on the type of powder & the consistency of operation. Like a lot of things, practice makes perfect. I suggest practice throwing charges directly into the pan & weighing to refine your technique. You might be surprised at what works to improve your charge accuracy.

Just IMHO...

[RC20]

That said and hoping to avoid an assumption.

Frankly its amazingly close then. Not even sure why you would ask that but.

Its not going digital, its going hybrid.

.3 with a mechanical of any kind is fantastic, leap for joy and all that. Frankly .3 is good with an Electronic dispenser . I see that all the time.

I can adjust for that by loading on the low side and snagging grains out of the flow tube till it hits what I want.

Seldom if ever an issue. Some small pistol and rifle loads that 3/10 makes a big difference but for the most part no.

What you frankly have to watch is the sale drift.


If your pan tare drifts off then you need to re-zero.

[F. Guffey]

I have powder measures and I have dispensaries, I even have Lee dippers, one set is black, one set is yellow and the last one is red. I have RCBS Uniflow and the small one that requires changing the rotor for different weights, and I have all of the rotors so I have to ask if he has the dispenser with the digital read out or is he using something like the Uniflow?


And then I have the trickler and before I confuse someone I have more than one trickler.

F. Guffey

[jski]

The powder was Hodgdon's H110. The powder dispenser is the RCBS Uniflow:

[mack59]

Mechanical powder measures, even the best, can vary even with a good metering powder. They are susceptible to variation in technique and static and other considerations. I do agree that a variation between high and low of .3 grains really isn't bad.

Given that you rechecked your Gempro by weighing known weights to verify its accuracy then it probably is variation from the powder measure and not the scale.

However the Gempro is a strain gauge scale and as such there are limits to it's accuracy, such scales are known to wander within a few tenths of a grain and more in some instances.

I would trust a 10-10 Rcbs scale before either a digital strain gauge scale or a powder measure.

For true accuracy one has to move up to a magnetic force restoration scale. But those are some significant cash.

[jmorris]

I would bet $1 that I could get better than .3gn with H110/296 with a dipper, the powder is quite fine and meters much better than any extruded powders.

I would inspect your measure for problems, if you have already tested your scale. Also worth noting if the measure is only off when your air conditioning is running or some other environmental variable that is messing with your scale, when the measure is not the problem.

[444]

I have used dippers quite a bit and in my experience they are pretty damn accurate.
I have also used an RCBS Uniflow powder measure for a couple decades and would honestly estimate I have thrown in excess of 20,000 charges with it and I agree that +/- .3 grains is about typical.
Which isn't as good as a dipper, but a lot faster.

I worked with a guy that owned a rifle and wanted to start reloading for it but wasn't willing to spend any real money to do so (sounds like half the threads on internet gun forums). SO, I suggested to him that he get a Lee Loader. At the time, the cost of a Lee Loader was less than $20 but he wouldn't risk less than $20 without me bringing one into work and demonstrating it to him. So after he saw that, he wanted to know how accurate the dipper threw a powder charge, so the next shift I brought in the dipper, a pound of powder, and a digital scale. Long story even longer, I found that if I dipped the powder, then scraped over the top with a business card that these dippers were FAR, FAR more accurate than I would have ever thought they were. Easily more accurate than my RCBS Uniflow. But again, they are slower.

Flash forward about 20 years, I own tons of reloading equipment. I probably have a half dozen powder measures both mechanical and electronic. However I often use a Lee dipper when I load rifle ammo. If I am throwing a charge, then trickling it up to weight, I stand there with a can of powder, a Lee Dipper, a powder trickler and a scale. Very low tech but it is every bit as accurate as any other way you want to dispense powder.

[F. Guffey]

I found that if I dipped the powder, then scraped over the top with a business card that these dippers were FAR, FAR more accurate than I would have ever thought they were. Easily more accurate than my RCBS Uniflow. But again, they are slower.

And then there are the Lee scientifically designed dippers. The difference between the 'scrape-um with a business card' and 'heap-um up with out scrapping is the difference between a starting load and a maximum load.

F. Guffey

[RC20]

I have an old model of that.

No where near 3/10 - frankly that's outstanding. Many bench rest types just volume load and it works.

What load are you working on and caliber?

If its 9mm or 25 then 3/10 is a possible issue up at max. Otherwise .........

[jski]

I'm loading for .30 Carbine, .357 Mag, .45 Colt most of the time. The .30 Carbine and .357 Mag aren't particularly sensitive to that kind of variation. But the .45 Colt for my S&W Mountain Gun could be. I haven't tried this experiment with Hodgdon's Titegroup, which I use for my .45 Colt rounds.

[Don Fischer]

I think it could be the dispenser or the scale Only with flake powder do I throw charge's directly into the pan, meter's really well. Ball measure's really well, but it and stick I don't trust. I throw them light and trickle up, every round! My scale is an RCBS 505 I've been using over 30 yrs. I've used different powders scales but my RCBS is pushing 30 now too. Scales, beam type and every digital I've heard of are accurate to +/- 1/10th grain. Give that 1/10th and add for the charge you threw with ball nad especially stick type powder's and the result's can be way off. trust the scale, not the powder measure. Want to know really how close your measure is throwing? Get it set to where you think it's right on, ball and stick powder, and throw 10 chgs into the pan. Multiply a single chg by 10 and weight the ten! Might put a scare into you!

BTW, they are not pan scales, they are beam scale's.

[hounddawg]

I could not care less about the accuracy. Plus or minus a tenth or two is good enough to develop a load. What you are looking for is precision so every charge you throw is the same as the charge you threw yesterday or last week. It might not be the same if you use a different scale but as long as it is the same on that particular scale you know every round will shoot like the last