scale calibration

[ChellieWiles]

atmospheric pressures, temperature, elevation and so on do not impact any function of a gravity scale (once zeroed), this can not be said for digital scales. if you are reloading in a basement, out of the way of wind and you calibrate your digital, after 10 minutes of reloading, your very presence alone changes the pressure and temperature of the environment you're standing in. When I use to run test on digital scales we would have to put these scales in laboratory's confined with no atmospheric variables or human bodies to get a true calibration. one flaw I noticed early on is that by the simple motion of your hand hitting the 'zero' button on the scale can cause over a grain variation from true zeroing from the vortex created in air by simple motion. when your hand heads down toward the scale, there is pressure from the front of your hand as well as a continued downward force of wind pressure for up to 5 seconds after motion. the same with breathing in the same room as a digital scale! you will get very accurate measurements but they will never be true. too many variables unless you have a lab with a robotic arm design to not displace any atmosphere to get true results.
every one of my handloads will shoot up to 9/10 duplicates through a chronograph. Powder companies have spent a very large amount of money and time in the design of their powder. And, when you accurately measure this powder, it will burn exactly the same as the charge before displaying the exact pressure in any certain chamber. I weigh out every one of my bullets (not brass) and sort the variances to get this type of perfection. Premium bullet makers are very good with them so there are only about 10-15 out of 50 that are different than the others by usually less than .5 of a grain.
Isaac Newton is known for the first person to grasp this understanding and knew by erasing variables, outcomes become more precise. Think of all the variables that are needed for a digital scale to function properly. Too many for a simple man like me.

[JASmith]

Those who complain about digital scales are living in the past. While I do keep a balance scale around in case there is power outage and I need to reload, my Chargemaster just chugs along. Yes, its accurate to +/- .1 grain, but that is really all a balance scale is accurate to as well...

I suspect that some of us have tried electronic scales on the cheap -- ~$30.00 versions. That is at least where my own prejudice comes from. I got tired of seeing the zero change between charges. I could do at most three charges before the scale started to drift.

My impression is that folks get excellent electronic scale results when they invest a fair bit more than they would for an average quality balance beam AND periodically check zero and calibration.

[bwaites]

atmospheric pressures, temperature, elevation and so on do not impact any function of a gravity scale (once zeroed), this can not be said for digital scales. if you are reloading in a basement, out of the way of wind and you calibrate your digital, after 10 minutes of reloading, your very presence alone changes the pressure and temperature of the environment you're standing in. When I use to run test on digital scales we would have to put these scales in laboratory's confined with no atmospheric variables or human bodies to get a true calibration. one flaw I noticed early on is that by the simple motion of your hand hitting the 'zero' button on the scale can cause over a grain variation from true zeroing from the vortex created in air by simple motion. when your hand heads down toward the scale, there is pressure from the front of your hand as well as a continued downward force of wind pressure for up to 5 seconds after motion. the same with breathing in the same room as a digital scale! you will get very accurate measurements but they will never be true. too many variables unless you have a lab with a robotic arm design to not displace any atmosphere to get true results.
every one of my handloads will shoot up to 9/10 duplicates through a chronograph. Powder companies have spent a very large amount of money and time in the design of their powder. And, when you accurately measure this powder, it will burn exactly the same as the charge before displaying the exact pressure in any certain chamber. I weigh out every one of my bullets (not brass) and sort the variances to get this type of perfection. Premium bullet makers are very good with them so there are only about 10-15 out of 50 that are different than the others by usually less than .5 of a grain.
Isaac Newton is known for the first person to grasp this understanding and knew by erasing variables, outcomes become more precise. Think of all the variables that are needed for a digital scale to function properly. Too many for a simple man like me.

I'm impressed by that degree of individual persistance. Theoretically, then, you should be able to shoot miniscule groups.

My experience, though, is that the vast majority of effective variables are once the trigger is pulled, not in the reloading process. I'm not saying we shouldn't try to be as exacting as possible in reloading, but I seriously doubt that anyone on this board can tell the difference in .1 grain +/- when actually shooting. There are a few serious marksmen here, and maybe stokesrj or LR1955 or some of the others can tell, but I know I can't.

Having read Carl Bernosky's reloading recipes, I am 100% convinced that its far more the shooter than the cartridge.

[ChellieWiles]

single hole groups out to about 250 yards. and bwaites, you are very right about it being the individual pulling the trigger that changes things the majority of the time. but I've had very good results of 1-2 inch groups or less at 500 yards with this approach. also, i do have my barrels made to withstand 100k pressures to reach velocities a bit higher than most shooters on many of my rifles.
now, as to "winners" of competitions...I have a very strong belief that the best shooters or the best of anything in this world do not compete. they realize that the only people they are truly competing against are themselves and would rather not deal with fan-fair.

[stokesrj]

This is a subject I have some knowledge of. My MOS in the USAF was Precision Measurement Equipement Laboratories, and later I was a state metrologist responsible for keeping the state standards of weights and measures certified to the then national bureau of standards for weights and measures, now called NIST (national institute standards and time). In this role I calibrated scales in a vacumn, oil free enviornment, with weights that were so precisely polished that if you allowed them to touch one another they would bond molecularly, becoming a single mass. I calibrated scales of mechanical design so precise that a single dust fiber caught in a knife and pivot interface could be detected.
Mechanical beam ballances are incredibly accurate, but they hold no advantage over the most precise electronic scales.

For our purposes as reloaders, both mechanical, and electronic scales of sufficient quality are far more accurate than needed. Electronic scales exist that can accurately detect to the smallest grain of powder, or even a tenth of a grain of powder. But none of us can afford them, and if we could then we coulndn't affor the enviornment to use them in. The scales are on the order of tens of thousnads of dollars and the enviornment on the order of hundreds of thousands of dollars. It is all moot. A goood quality electonic or mechanical scale is all that is needed.
A good quality scale costs in the $200 range.

The most accurate practical scale available to us as reloaders is the Prometheous. The Prometheous I is a mechanical scale capable of uniform powder charges to the single grain of powder. The Prometheous II is both more accurate and faster. A Promethious I, if you can find one for sale is around $1,200 and a Prometheous II cannot be purchased, only leased.
Here is an article on the Prometheous I including six sigma capabilities compared to scales such as the Ohaus 5-10.

http://www.6mmbr.com/prometheus.html

Here is a video of the Prometheous II in acton.

http://www.youtube.com/watch?v=6scLPhkT-8w

I have a friend that owns both and has the Promethious II interfaced to his Dillon 650. It is a nice piece of gear and he wins his share of matches using ammunition loaded on it. But, I don't believe it is necessary to get to single grain of powder load uniformity. There are far more significant factors such as consistent neck tension and simply tuning loads for forgiveness. I've seen him beat at 600 yard mid range matches by folks throwing charges on a Niel Jones powder measure that costs one third the price.
Respectfully,
Bob Stokes

[LR1955]

single hole groups out to about 250 yards. and bwaites, you are very right about it being the individual pulling the trigger that changes things the majority of the time. but I've had very good results of 1-2 inch groups or less at 500 yards with this approach. also, i do have my barrels made to withstand 100k pressures to reach velocities a bit higher than most shooters on many of my rifles.
now, as to "winners" of competitions...I have a very strong belief that the best shooters or the best of anything in this world do not compete. they realize that the only people they are truly competing against are themselves and would rather not deal with fan-fair.

CW:

So, your chrono readings show that nine out of every ten shots are identical in velocity? And this is because of your mechanical powder scale?

Why would anyone care if their barrel could take 100K of pressure? I always thought that it was the chamber that counted more so than other parts of the barrel?

Anyway, given your ability to shoot one hole groups at such ranges, you must be the top Bench Rest shooter in the world. I am sure you can provide us with a link that shows your world records?

LR1955

[mongoosesnipe]

I cheek the calibration on my 1010 before every reloading session just in case and so long as it is in the same spot I left it it has never needed adjusting if I move it to a different area of the bench small adjustments are nessisary my bench is level but not perfect but I have found loading to not be any slower when weighing powder charges ou just calibrate the balance dial in your charge and add powder until it balances honestl most of my loading is done on my Dillion 650 and once I dial in the charge on the powder meter I just check its accuracy with the balance every time I add primers and powder to the set up it has never varried with good metering powder the vast majority of my reloading is done with varget with rifle and titegroup for pistol and I have had great luck with both price isn't really a factor in my decision to keep with the 1010 it cost more than most of the digital scales on the market but honestly if I start competing at a level where I am weighing each case an bullet and sorting all of my components bases on the match string I will be shooting I will portably get a digital scale as that mount of measuring and sorting would be difficult with a balance

[Drifter]

...every one of my handloads will shoot up to 9/10 duplicates through a chronograph.

You obviously have a unique gift, as you are likely the only person on the planet that can achieve that type of consistency, especially considering the average margin of error for most electronic chronographs.

Due to such a high level of skill that most will think impossible, you might be better served to leave some things unsaid.

Just saying...

[ricsmall]

my old rcbs (made by pact) digital scale and powder measure have loaded perhaps 10,000 rounds in the last 10-11 years and are still spot on. I think calibration and environmental control are the two biggest factors. Also the little bit of benchrest shooting I was involved in, the loading was done with a precision powder measure, harrell I think, the only charges weighed were the first and about every tenth. No, I never won, but the other guys using same equipment did. Just shows you dont have to weigh every powder charge with properly functioning and maintained equipment.

[rickOshay]

Originally Posted by ChellieWiles
...every one of my handloads will shoot up to 9/10 duplicates through a chronograph.


I once saw Big Foot shoot a single hole at 1000 yds.

[BjornF16]

Pulled out the waders...it's getting deep in here!

[ChellieWiles]

Anyway, given your ability to shoot one hole groups at such ranges, you must be the top Bench Rest shooter in the world. I am sure you can provide us with a link that shows your world records?

LR1955

if you have any video/pictures of competitors on the range, from the front angle back towards the bench, you'll see the glitter of my scope way back about a half mile behind him with a USMC Sniper spotter alongside gauging windage and what-not.

[fanofflyn]

Once I had a digital scale that had a platform, and every now and then it would get erratic. I discovered that a couple of grains of the powder would wedge beneath the platform and throw off the readings. After I popped off the platform and cleaned it, it did return to normal. I bought a later model of the same scale, and they changed the design such that this problem no longer existed. I changed because it would read four times faster, but I kept the old one for backup. I'm totally happy with their reliability.

[sneaky one]

Good lorde chel wil-let it go-adapt.. The digital scale is the best way to do our reloading. The old school beam scale is sooo inaccurate now days- compared to a digital scale . I always use the alum. pan as the start point-then hit tare- then measure, then hit tare after each wt. check -- then measure. ,,repeat...always triple check everything. Ahhhh... the new world is a rising, with more intell than the past old stiffers= non yielding, old grumps---had access to. hee-hee! Change it up!! Look to the future, plan for it. Don't live in the past.

[LRRPF52]

I also use match bullets as weights to check my scale's consistency, and it is within .2gr of weight. I think neck tension would play more of a role in velocity before .2gr, but who knows...

Maybe I should take my digital scale out to the skeet range, and go to a beam scale?