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Posted: 8/27/2012 1:08:16 PM EDT
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So, I bought a pretty expensive Sartorius scale that is supposed to have 0.02 grain accuracy. However, it's giving me grief and I'm debating the purchase.
I zero with the powder pan on the scale. I measure out a few powder charges and load them into cartridges. After several cycles of this, I've noticed that the "zero" weight will shift - sometimes significantly (by as much as an entire grain). So, with the pre-amble out of the way - how accurate are powder drops, and what are the most accurate powder drops out there - are there any that are more than .1 grain accurate - and does it really matter? |
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Drakich,
Try plugging it in to a good surge protector, like one for a home theatre setup. Make sure it is not near any fans or a/c vent. Keep away from fluorescents. You can try these to reduce interference to the scale. I have noticed it is very susceptible to cell fones being near it. Re-zero it every few drops. There is another Sartorius that is really accurate, accurate and fast to .001gr, but costs over $1200. The Gd-503. You can look at the GemPro 250 which is accurate down to .02gr and around $150. Does it really matter, that is up for debate. All these scales I mentioned are used by guys that I shoot with and compete against in F-class matches and they all swear by their particular voodoo. Me? I use a Pact scale and it is very accurate to 0.1gr and that is good enough for me. Hope that helps. SY |
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Any equipment has a few tricks for it to run well.
Don't know anything about your stuff but here are some things I have learned. Beam scales––Set them up level on a firm surface,best near eye level. I have a special shelf for mine. Zero scale,double check all slideing weights are in notches . As others have said the slightest draft or wind will mess you up. I have used both Lyman and RCBS beam scales ,both to good use I use the simple old school Lyman #55 measure. Don't trust any charges thrown with powder less than a third of the hopper. Use it with consistency and it will throw very good charges I have a friend who has all sorts of electronic scales but he throws his charges with a Lyman 55 that he has duct taped a empty powder bottle to the small hopper to give it bigger capacity. With this he won the Canidian National Palma matches several years ago. If it is good for him it works for me |
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Quoted:
Drakich, Try plugging it in to a good surge protector, like one for a home theatre setup. It's plugged into a surge protector, but I'll see if upgrading to a better model does the trick. Make sure it is not near any fans or a/c vent.
My set up is in my garage. No ventilation at all! Door is actually sealed very well, no draft. So they only air movement comes from my movement. It isn't a whole lot. Keep away from fluorescents.
How far away? Overhead lighting is actually fluorescent. Not a lot of lighting options in the garage though, so this worries me a bit. You can try these to reduce interference to the scale. I have noticed it is very susceptible to cell fones being near it.
Noted. Re-zero it every few drops.
Yeah, was having to do this anyway. There is another Sartorius that is really accurate, accurate and fast to .001gr, but costs over $1200. The Gd-503. You can look at the GemPro 250 which is accurate down to .02gr and around $150.
$1200 is a little more than I want to spend on a scale. Does it really matter, that is up for debate. All these scales I mentioned are used by guys that I shoot with and compete against in F-class matches and they all swear by their particular voodoo.
Me? I use a Pact scale and it is very accurate to 0.1gr and that is good enough for me. My original plan was to use my Hornady electronic dispenser to drop a charge a grain or two under, then trickle the rest in, but the variation of +/- 1 grain is worrying me - because I know the cheapo Lee powder measure and the Hornady electronic dispenser don't have variations that large. |
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Let the balance warm up for 10-15 min and see if your zero is stable. If it still drifts by 1 grain call the manufacturer and see what they say. This may have done the trick. Turned on the unit last night, calibrated, and zeroed it with the powder pan. Came back 30 minutes later, and the measured weight had drifted up. Re-zeroed it, and left it overnight, and it stayed stable. I also moved it further away from an extension cord / power strip and leveled it a little better (this stuff is in my garage and there is a slight slope on the floor). |
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Quoted:
How much does one kernel of powder weigh? Std ball or flake powder I mean. Does it weigh more than .02 grain? Using my Sartorius analytical balance that weighs to 0.0001 grams (0.0015 grains) I have the following weights: Ten kernels of IMR 4064 = 0.0172 grams = 0.265 grains one kernel then = 0.0265 grains Ten 'balls' of H335 = 0.0020 grams = 0.0308 grains one 'ball' then = 0.00308 grains |
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Quoted:
Quoted:
How much does one kernel of powder weigh? Std ball or flake powder I mean. Does it weigh more than .02 grain? Using my Sartorius analytical balance that weighs to 0.0001 grams (0.0015 grains) I have the following weights: Ten kernels of IMR 4064 = 0.0172 grams = 0.265 grains one kernel then = 0.0265 grains Ten 'balls' of H335 = 0.0020 grams = 0.0308 grains one 'ball' then = 0.00308 grains You do get the prize for checking this out and reporting back I honestly wondered if a scale with .02 grain sensitivity would register this between kernaes of powder. I've always subscribed to the + 0.1 grain variance, and if my measure throws to that level, I'm OK with it. If others want to go after this level of precision, more power to them, it was just never for me. I've never attempted chasing down to .02 grain variances, so I just wondered what a kernel of powder weighed. |
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Quoted:
You do get the prize for checking this out and reporting back I honestly wondered if a scale with .02 grain sensitivity would register this between kernaes of powder. I've always subscribed to the + 0.1 grain variance, and if my measure throws to that level, I'm OK with it. If others want to go after this level of precision, more power to them, it was just never for me. I've never attempted chasing down to .02 grain variances, so I just wondered what a kernel of powder weighed. So, I did a little more playing around last night. Lately I've been using WCC844 exclusively (because I bought a shitload of it), but I have various 1 lb lots of other powders (CFE223, Reloader 17, Hodgon Benchmark, H335, you get the idea). I have the following: * Sartorius electronic scale accurate to +/- 0.02 grains. * Hornady electronic dispenser/scale, accurate to +/- 0.1 grains * Really cheap (Lee? Hornady? - it's Red, no name on it) manual powder dispenser * Hornady powder trickle What I had been doing was dispensing using the Hornady electronic scale, verifying the measurement on the Sartorious scale (usually re-zeroing in between), and then dropping the powder in. Very slow process. The variance on the Hornady electronic dispenser was around 0.1 to 0.2 grains (although sometimes it was dead on) It, however, turns out that WCC844 meters *really* well in the cheap powder dispenser. I'm working on a 69 grain SMK w/22.5 grains load, OAL ~ 2.258. Variance on the powder measure was +/- 0.02 grains except an odd throw or two that were 0.04 grains over. +/- 0.2 grains is too much variance for me, but 0.04 grains is ok. |
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