charge issue

[Bulldog1856]

Hey guys hoping for some help. I am newish to reloading and am having an issue with my powder charge. I am using unique powder through a Lee auto disc. heres the rub...Lee states that the .61 disc should give me 5.6 grains. i weigh it out using my hornady digital scale and i am consistantly getting 4.9 grains.the Lee safety scale is telling me almost the same thing. Should i increase the auto disc trusting the scale or trust the disc? I have a feeling the 20 rounds i have loaded will have to be pulled as i suspect they are undercharged.

[promod1385]

Go back and RTFM! Trust your scales... Manufacturing tolerances in the auto disk and in the powder can make a difference.

[Seismic Sam]

Yes, trust the scale, and seeing as you're getting the same results with a digital and a balance beam scale means your posterior is covered there.

There are a variety of factors that can affect most measures, and several are:

1. The amount of powder in the hopper.
2. The Lot # of the powder you are using. This SHOULD NOT and generally ISN'T an issue, but I have run into it a few times, so blindly assuming that all of one brand of powder has the same metering density has a small amount of risk or uncertaintly to it.
3. Any other ambient vibration on your bench while metering powder can have a relatively noticable effect, and the amount of impact of the measure going from stop to stop can make a difference.
4. And finally, the powder measuring cycle can have a huge difference in the charges thrown. You want to go from the disc in the "fill" position to the dump position and then back again. This allows the maximum time for the powder to settle in the disc cavity. Going from dump to fill to dump is a bad idea, because there is a difference in powder settling in the first few seconds, so a half second in fill position will give you a different weight than 1 second in fill position, and so on. You want to give the powder the longest time possible to settle in the disc before you throw it.

[wrench]

Agreed, trust the scale. My Lee auto disk measures consistently low-I trust my scale and choose the size hole that throws the charge I want, don't trust the chart.

[Bulldog1856]

SS and wrench... Thank you very much for your courteous responses. That is what I figured would be the answer. I reviewed my books multiple times and researched first but was hoping for confirmation from experienced reloaders that I was correct in trusting my scales not the equipment. Multiple rechecks and weights later I know I have the correct charge now. Thanks again guys.

[Seismic Sam]

And finally, I will add my usual rant about digital scales, which can be unreliable and/or inaccurate. I have a Cabela's $85 digital scale that has a plastic measuring pan that can generate enough static electricity to make the powder particles cling to the pan, and it has a brutal zero drift of about half a grain a minute, so if you weigh the powder 2 minutes after you zero the scale, your weight will be a grain higher than it actually is...

[engnerdan]

And finally, I will add my usual rant about digital scales, which can be unreliable and/or inaccurate. I have a Cabela's $85 digital scale that has a plastic measuring pan that can generate enough static electricity to make the powder particles cling to the pan, and it has a brutal zero drift of about half a grain a minute, so if you weigh the powder 2 minutes after you zero the scale, your weight will be a grain higher than it actually is...

on this topic, did you try spraying down the scale with "Static Guard"? I read about it online and how well it works. When I bought my cheap Hornady digital scale I actually stopped to buy the Static Guard on the way home from Gunstop. I removed the pan and pedestal. Sprayed the whole scale down and the pedestal and let it dry. I have had no problems with drift.

[bulletproof]

Don't trust the Lee Safety Scale, it's junk. Worst product Lee makes IMHO.

If anyone disagrees I have one to sell.

[Pat Cannon]

Don't trust the Lee Safety Scale, it's junk. Worst product Lee makes IMHO.

If anyone disagrees I have one to sell.

I disagree that it's junk, mine works fine, it's the best $20 scale out there. It's just not for anybody who's in a hurry. It's more aimed at the Geo-Metro-driving, over-the-air-TV-watching, Boxer-lager-drinking, Swisher-cigar-smoking demographic (e.g., me). I do agree that every other Lee product seems to be better than the Safety Scale.

And +1 to what everybody says about the Auto Disks. Just use the chart to get in the ballpark, then weigh. Looking at my notes from some recent .357 Magnum loads of Titegroup:

0.37cc disk, per chart: "4.4 gr", actual weights 4.0 - 4.1 gr.
0.40cc disk, per chart: "4.7 gr", actual weights 4.3 - 4.4 gr.
0.43cc disk, per chart: "5.1 gr", actual weights 4.7 - 4.9 gr.
(Did you know the numbers on the disks are cubic centimeters?)

BTW that load's my 'gamer' load for steel matches & IDPA this year -- not much muzzle flip but it reliably knocks down the poppers. Haven't chronoed it; I think I'm legal in IDPA. Pretty sure, actually, since I only need 665 fps under the wimpy new SSR power factor.

[Pat Cannon]

...Lee states that the .61 disc should give me 5.6 grains. i weigh it out using my hornady digital scale and i am consistantly getting 4.9 grains.the Lee safety scale is telling me almost the same thing. Should i increase the auto disc trusting the scale or trust the disc? I have a feeling the 20 rounds i have loaded will have to be pulled as i suspect they are undercharged.

I'd just shoot'em.

DISCLAIMER: Confirm this with somebody more expert than me. (There are plenty!)

There are some powders that do goofy things like HIGH pressure if you load them too light, and of course you don't want a bullet stuck in the barrel, especially if you pull the trigger on the next one before you realize it, but my GUESS is, you're in a safe range. What powder is it? Is 4.9 grains on the chart of the manual you're looking at? If so, you just have some light rounds, no biggy... oh unless you're one of those guys who's all picky about the exact point of impact.

[Bulldog1856]

5.5 grains is the starting charge listed. I doubt it would cycle correctly as low as it was. I was going for soft loads but that was too low.

[Pat Cannon]

5.5 grains is the starting charge listed. I doubt it would cycle correctly as low as it was. I was going for soft loads but that was too low.

Ah. Well, we all gotta pull some bullets eventually. 20 ain't so bad.

This is one of the reasons I don't think this silly auto-loading pistol fad is going to last.

[engnerdan]

5.5 grains is the starting charge listed. I doubt it would cycle correctly as low as it was. I was going for soft loads but that was too low.

You might be surprised how little powder it takes to operate some guns. A lot of the loads guys use to make 125pf for "gaming" are well below the minimum load on charts. What caliber are you loading for?

[Pinnacle]

Trust your scale...

Think of it this way;

"In G-D we trust, all others we weigh..."

[sgruenhagen44]

I try to keep my hopper over 50 % full when reloading. All my lee discs are a little light. Trust your scale!