As I continue to read and lean here while incorporating new information in my reloading I noted the importance of having a digital powder scale. After a little research I ordered one and have been using it for a week or so. What a difference. It is so much easier and faster now for booth my rifle loads and my hand guns. Thanks.
A thank you
- Thread starter anrfknm
- Start date
What did you have before, what do you have now?
snert
Silver $$ Contributor
I am still using a scale and various Redding measures. LAst night threw 500 23 grain Benchmark loads. Weighed every 5th one. Never had to change the thrower. I do, however, set my measure up to throw half a charge, and double throw each load, counting on law of averages to get me even closer. It works, especially with the 30BR and 10X measures which are darned accurate.
I just don't have space or the right area for a digital or electronic measure.
I just don't have space or the right area for a digital or electronic measure.
so, if you throw double your load, then split it between two cases, do you decrease your error by 50%?
snert
Silver $$ Contributor
Well, here is my non-math answer:
First, i was told by an engineer type that by halving and double drop, the degree of "miss" is lessened. I took his word for it.
i use a 10X Redding for light charges and mostly ball powders. I still weigh regularly to make sure it is accurate and not drifting.
I am able to throw 17.5 of H335 using two throws on the 10x more consistently than I can do it in one throw using a BR-30. So maybe it has to do with the design, maybe not, but I find that if I try to do it on one throw using either the 10x or the BR30, I get more "waffle" or inconsistentcy.
So...there you have it
First, i was told by an engineer type that by halving and double drop, the degree of "miss" is lessened. I took his word for it.
i use a 10X Redding for light charges and mostly ball powders. I still weigh regularly to make sure it is accurate and not drifting.
I am able to throw 17.5 of H335 using two throws on the 10x more consistently than I can do it in one throw using a BR-30. So maybe it has to do with the design, maybe not, but I find that if I try to do it on one throw using either the 10x or the BR30, I get more "waffle" or inconsistentcy.
So...there you have it
Dusty Stevens
Shiner
If your thrower throws a bit low and you throw 2 low ones thats twice as much low as one low one. (Or thereabouts)
snert
Silver $$ Contributor
His explanantion was that over the course of 20 throws, if 5 are off, not in a row, as per usual odds, then you have 5 small misses, vs 5 big misses.
mtncwru
Gold $$ Contributor
Here's the math answer. Please know that I picked the example numbers because they're easy to work with; I would expect much lower variance from actual powder measures:
It's going to depend on your specific powder throwing mechanisms, and whether the variance of a given device is a percentage of the overall measured amount, or by an absolute weight.
If your thrower varies on absolute weight (so by, say, +/- 1.75 gr., no matter your target weight), then by throwing twice you've doubled your maximum error as Dusty points out. If your measure varies on a percentage of target weight (say, +/-10%), then it's not that you wind up with smaller errors (since you still have the same total potential error margin), but rather that you can wind up with cancellation of errors.
I setup a sample in Excel, assuming a +/-10% margin of error for a given throw, and assuming that heavy and light throws occurred with equal frequency and at random. I then used the Excel random number generator to give me a set of 600 values from 0 to 1; half were multiplied by 0.1 and the other half by -0.1 to determine the percentage of error for each throw. Those errors were then applied to a charge weight of either 8.75 (half throw), or 17.5 (full throw). The half throw charges were then randomly sorted to distribute the heavy and light charges, before those charges were added together to derive the total charge list. Selected stats for the charge lists are below.
Half Charge
StdDev 0.74621
Extreme Spread 3.02
Max Charge 19.06
Min Charge 16.04
Avg Charge 17.56
Median Charge 17.56
Full Charge
StdDev 1.002899
Extreme Spread 3.47
Max Charge 19.24
Min Charge 15.77
Avg Charge 17.46
Median Charge 17.51
So if you have a thrower that varies based on percentage of target weight, it would appear that half-throwing your charges may produce more consistent loads, with a less extreme spread across the sample. Whether or not that extra consistency makes a difference over, say, weighing each load, is going to vary on a case-by-case basis. It's something you would need to test and verify for each measure/powder combo you want to use.
The main risk of this is the need to activate the lever twice, and thus adding double the human intervention and double the risk of human error. I say this as someone who tracks and works to mitigate medication errors in healthcare: each touchpoint is an opportunity to introduce error into the system, and so should be examined for necessity and potential alternatives. In addition to the safety aspect there's also the time aspect: the faster I can load quality, safe ammo, the better.
My preferred system, both from a time and safety standpoint, is to weigh every charge on my GemPro. I drop most of a charge (within 0.2 gr., usually) with my Lee thrower, then trickle up into a pan on the GemPro. +/- 0.06 gr. is acceptable for me; anything that's too heavy just gets dumped back into either the thrower or the trickler, then gets re-thrown.
It's going to depend on your specific powder throwing mechanisms, and whether the variance of a given device is a percentage of the overall measured amount, or by an absolute weight.
If your thrower varies on absolute weight (so by, say, +/- 1.75 gr., no matter your target weight), then by throwing twice you've doubled your maximum error as Dusty points out. If your measure varies on a percentage of target weight (say, +/-10%), then it's not that you wind up with smaller errors (since you still have the same total potential error margin), but rather that you can wind up with cancellation of errors.
I setup a sample in Excel, assuming a +/-10% margin of error for a given throw, and assuming that heavy and light throws occurred with equal frequency and at random. I then used the Excel random number generator to give me a set of 600 values from 0 to 1; half were multiplied by 0.1 and the other half by -0.1 to determine the percentage of error for each throw. Those errors were then applied to a charge weight of either 8.75 (half throw), or 17.5 (full throw). The half throw charges were then randomly sorted to distribute the heavy and light charges, before those charges were added together to derive the total charge list. Selected stats for the charge lists are below.
Half Charge
StdDev 0.74621
Extreme Spread 3.02
Max Charge 19.06
Min Charge 16.04
Avg Charge 17.56
Median Charge 17.56
Full Charge
StdDev 1.002899
Extreme Spread 3.47
Max Charge 19.24
Min Charge 15.77
Avg Charge 17.46
Median Charge 17.51
So if you have a thrower that varies based on percentage of target weight, it would appear that half-throwing your charges may produce more consistent loads, with a less extreme spread across the sample. Whether or not that extra consistency makes a difference over, say, weighing each load, is going to vary on a case-by-case basis. It's something you would need to test and verify for each measure/powder combo you want to use.
The main risk of this is the need to activate the lever twice, and thus adding double the human intervention and double the risk of human error. I say this as someone who tracks and works to mitigate medication errors in healthcare: each touchpoint is an opportunity to introduce error into the system, and so should be examined for necessity and potential alternatives. In addition to the safety aspect there's also the time aspect: the faster I can load quality, safe ammo, the better.
My preferred system, both from a time and safety standpoint, is to weigh every charge on my GemPro. I drop most of a charge (within 0.2 gr., usually) with my Lee thrower, then trickle up into a pan on the GemPro. +/- 0.06 gr. is acceptable for me; anything that's too heavy just gets dumped back into either the thrower or the trickler, then gets re-thrown.
A couple of years back I bought a starter kit from RCBS that had most of what was needed to start reloading. It came wit a cheap RCBS mechanical scale that I've used ever since. A few days back I received the Frankford Arsenal Platinum Series Precision Scale I purchased and have loaded both pistol ammo and rounds for my rifle. A lot easier with the digital scale.
Should I not use those Lee scoops?
Raythemanroe
Bullet Whisperer
My head hurts, who throws for accuracy?
Ray
Ray
Use both to compare accuracy , check one with the other... What I am getting at is , digital drifts so don't get complacent , always check everything twice , Safety first... Find something that you know weighs the same like a bullet or coin and check the scale occasionally....
Will do.
LarryDScott
Site $$ Sponsor
Ya'll are just toooooo deep for me. LDS 
Sorry for starting this 
... anyhow - another wrench for the "real math" example above, if you throw two half loads, you will have to have two perfect throws to reach the target weight, if you just throw one load, you will only need one accurate throw....
Just kidding - whatever works for you, continue to do it that way, I just wanted to be the forum troll when I posted the initial one...
... anyhow - another wrench for the "real math" example above, if you throw two half loads, you will have to have two perfect throws to reach the target weight, if you just throw one load, you will only need one accurate throw....
Just kidding - whatever works for you, continue to do it that way, I just wanted to be the forum troll when I posted the initial one...
Last edited:
pirate ammo
Guaranteed to take the wind out of their sails
no need to be sorry,,just sit back and see what happens,,I use a digital on my handgun stuff,,works great,,Sorry for starting this
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