Scale ideas?

[SeabeeKen]

I have a little used gempro 250 id let go. Left over from scale testing i did a while back. Works like new

 

[1066]

Thank you for your long and detailed reply Ned. I fully except what you are saying - accurate and reliable powder weighing take one of the many variables out of the equation, and I feel the 1 kernel of Varget =.02gn =1fps as a fair guess and a workable figure.

I don't know anyone who actually cuts kernels to get the exact weight, with most excepting a +/- .02 or a single kernel as acceptable - A finer powder might give closer results.

My point is, you don't really need the latest high end scale to achieve this. Ten years ago you could have spent $1,500 or more on the latest offering from Mettler, Ohaus, Sartorious or any other high end analytical scale. These scales were used for exacting work by technical laboratories with no problems and, to be fair, weighing .02 grain is like weighing lumps of coal to many of these sub milligram scales.

Someone invents a new mousetrap and suddenly "force restoration" is the latest "must have" tool, all very nice, but just round the corner we have, Surface Acoustic Wave (SAW) scales or some other latest technology.

I think many reloaders underestimate the humble beam scale - true, they are not all good, but many are reliable, repeatable and quite capable of single kernel resolution. One of the weaknesses is the short length of the beam that makes decerning single kernel beam movement difficult to see - now easily overcome by use of a cheap USB camera or phone set-up.

Monitor Balance Beam with Magnified Image on SmartPhone « Daily Bulletin

If you use a balance-beam scale to weigh powder and reloading components, here's a clever way to magnify the view of the beam tip. Of course you can use an old-fashioned magnifying glass, clamped in place, to upsize the view.

bulletin.accurateshooter.com

I have beam scales that resolve down way below 1mg or .0154gn.

This is a common, basic old M500, not even trying to be exact:

And a 505 :

A 10/10:

Don't write off the humble beam scale - they just work.

 

[Fuj]

Something I read about what Speedy Gonzales was using.....
And starting at a measly $3800 bucks, You can own a "Promethius"
The ultimate beam scale on steroids.

Internals.....

 

[1066]

Or you could find something equally as accurate for $50 at your local flea market:


or something twice as accurate for $100:

 

[Tesoro]

I bought a new Redding a few years ago that will most certainly weigh one stick of IMR 4350.
It hasn’t been sent anywhere or had anything done to it either. It could be the only one they’ve ever made that will do that but normally I’m not that lucky. It’s better than the RCBS 10 10 that I bought in the ‘70s ever was. Also have a small electronic scale to double check myself before loading.

Why dont you use check weights to the closest .5gr of your load with a balance beam? Alot simpler and takes out all concerns.

 

[Tesoro]

absolutely not for PRECISION SHOOTING, hunting and plinking just fine

Explain this!!!

 

[justpassinthru]

Why dont you use check weights to the closest .5gr of your load with a balance beam? Alot simpler and takes out all concerns.

If I set my Redding to 44.6 grains, it's convenient to drop a charge weight it, then double check it on the electronic scale. The little electronic is a Gemini 20 and it's a great little scale that I've used a lot. Besides, it's possible that I'd screw up adding up the weights.
When checking my scales, I use check weights. I trust them, it's me I'm concerned with.

 

[Tesoro]

If I set my Redding to 44.6 grains, it's convenient to drop a charge and put it on the electronic scale to double check myself. The little electronic is a Gemini 20 and it's a great little scale that I've used a lot. That's just how I prefer to do it. Besides, it's possible that I'd screw up adding up the weights.
When checking my scales, I use check weights. I trust them, it's me I'm concerned with.

ok!

 

[Ned Ludd]

Thank you for your long and detailed reply Ned. I fully except what you are saying - accurate and reliable powder weighing take one of the many variables out of the equation, and I feel the 1 kernel of Varget =.02gn =1fps as a fair guess and a workable figure.

I don't know anyone who actually cuts kernels to get the exact weight, with most excepting a +/- .02 or a single kernel as acceptable - A finer powder might give closer results.

My point is, you don't really need the latest high end scale to achieve this. Ten years ago you could have spent $1,500 or more on the latest offering from Mettler, Ohaus, Sartorious or any other high end analytical scale. These scales were used for exacting work by technical laboratories with no problems and, to be fair, weighing .02 grain is like weighing lumps of coal to many of these sub milligram scales.

Someone invents a new mousetrap and suddenly "force restoration" is the latest "must have" tool, all very nice, but just round the corner we have, Surface Acoustic Wave (SAW) scales or some other latest technology.

I think many reloaders underestimate the humble beam scale - true, they are not all good, but many are reliable, repeatable and quite capable of single kernel resolution. One of the weaknesses is the short length of the beam that makes decerning single kernel beam movement difficult to see - now easily overcome by use of a cheap USB camera or phone set-up.

Monitor Balance Beam with Magnified Image on SmartPhone « Daily Bulletin

If you use a balance-beam scale to weigh powder and reloading components, here's a clever way to magnify the view of the beam tip. Of course you can use an old-fashioned magnifying glass, clamped in place, to upsize the view.

bulletin.accurateshooter.com

I have beam scales that resolve down way below 1mg or .0154gn.

This is a common, basic old M500, not even trying to be exact:

And a 505 :

A 10/10:

Don't write off the humble beam scale - they just work.

I'm not a beam scale hater in any way, shape, or form. Folks should be using whatever weighing method satisfies their needs and budget. It's really that simple. Realistically determining what those needs might be in terms of accuracy/precision/weight increment seems to be the real issue here.

For clarification, MFR is not "new" technology; it has been around for a long time. What I was referring to in an earlier post was that if one was going to buy an electronic balance, MFR is the way to go. Buying a junk chinese torsion balance made to look like an expensive laboratory analytical balance just because it might seem relatively inexpensive can be a mistake. The obvious downside to buying a quality MFR balance is the relatively high cost.

 

[big5ifty]

Understanding and identifying limiting sources of error is an important part of the reloading and shooting process. One needs to have some grasp of this concept so that they can choose a suitable method for weighing powder that fits their needs and their budget.

Is there a point of diminishing returns when it comes to powder weighing ?

The smallest increment is the weight of one granule. The weight of granules is not identical - by definition powder charges are not identical even if the scale says so.

To what degree is it necessary to control powder weight for a particular caliber in a precision discipline like 1000 yard benchrest ?

I still don't have a clear understanding of how the variation in the weight of primer compound - not the weight of the primer - is able to skew results even when powder is dispensed to 1/100 of a grain, but I do believe it contributes to variance even if powder charges are identical.

When do enviromentals have a bigger effect than powder charge variation ?

 

[Ned Ludd]

Is there a point of diminishing returns when it comes to powder weighing ?

The smallest increment is the weight of one granule. The weight of granules is not identical - by definition powder charges are not identical even if the scale says so.

To what degree is it necessary to control powder weight for a particular caliber in a precision discipline like 1000 yard benchrest ?

I still don't have a clear understanding of how the variation in the weight of primer compound - not the weight of the primer - is able to skew results even when powder is dispensed to 1/100 of a grain, but I do believe it contributes to variance even if powder charges are identical.

When do enviromentals have a bigger effect than powder charge variation ?

I would consider cutting kernels past the point of diminishing returns, LOL. In reality, if one is careful and observant while weighing out the first 5 or 10 charge weights, it is not too difficult to determine where each powder throw "wants" to be with respect to the desired/calculated numerical charge weight. Typically, the difference between where most of the charges "want" to end up and the calculated value will be equal to or less than the average weight of a single kernel, assuming the weighing apparatus is capable of measuring to that level. Because we're often throwing a couple thousand or more kernels per charge, we can therefore let the statistics work in our favor in the following way.

To do this, I weigh out charges for my sighters/foulers first, using a Mettler Toledo analytical balance set to .0001 g readability, paying close attention to the range (hi/lo) and approximate median charge weight. I do this to begin making a decision about how tight I can hold the charge weight tolerances. The balance I use can actually be set to .00001 g readability, but trying to weigh powder down to that fine a precision would be ridiculous, maddening, and would probably end up causing me to take a hammer to my wonderful balance. That would be less than 1/100th of a kernel readability. I really like my balance, so I don't want to do that. Anyhow, after watching charge weights carefully while preparing sighters/foulers, it is really not too difficult to keep the overall range to as low as +/- half a kernel or so, certainly within +/- one kernel once I start weighing powder for my test rounds, or rounds to be used for record shots in a match. I've worked in a laboratory all of my adult life, weighing milligram quantities typically many times per day, so weighing powder this way is really second nature for me at this point.

The most important question is whether this is actually necessary for what I do. I would argue that it is not. We're talking about a charge weight variance that calculates out to a theoretical velocity variance of well under 1 fps, so no, I can't shoot that, not even close. Nonetheless, weighing powder to that level of precision isn't that difficult or time consuming with the right setup. So it's not like doing it that way makes the process far more painful for me than it would be if I settled for a much larger precision increment. To each their own. What I know is that I never, ever, ever have to worry about charge weight variance in my loaded rounds at a match, and when I see unacceptable velocity variance during a load workup, I know it isn't due to excessive charge weight variance. In other words, charge weight effectively ceases to be a "variable". Those things are worth a lot to me, so I choose to do it that way. Only the individual can decide for themselves whether doing any step in the reloading process to some particular level is worth the amount of time and effort it requires. But to make an informed decision regarding whether some particular method is worth the time/cost usually requires some kind of estimate to be made, such as correlating a certain amount of charge weight variance to a certain amount of velocity variance. These kind of estimates are probably routine to anyone that works in a research laboratory, but they may not be so obvious to others. So I try to provide these detailed [and probably excruciating to some, LOL] explanations of how I do things, to possibly help others decide for themselves what route they may wish to take.

In general, I would think that many reloaders would be perfectly fine weighing powder to about +/- 0.1 gr. Depending on the cartridge/powder, that would likely keep the predicted velocity variance to somewhere around +/- 10 fps, or slightly less. Further, it's neither difficult nor expensive to do. That kind of precision increment could easily be achieved with a number of different weighing options. Most importantly, weighing options that don't cost $600-$700 or more.

If one wanted to go to the next level of precision in powder weighing, something like let's say +/- .02 gr charge weight range, there may be a few less expensive weighing options that simply can't reliably hold such tolerances. So it may cost a bit more, but you might also be getting better reliability, features, and/or ease of use, as well the tighter tolerance.

If one really wants to take it to the limit, such as weighing powder to +/- half a kernel or better, we're really talking about a limited number of balances that can reliably achieve that, and they're not going to be cheap. This is where you're really going to want a MFR analytical laboratory balance that will cost maybe $600-$700, to well over $1000 depending on the brand and features selected. The increase in cost to go to this level means one better think pretty carefully about what they're going to achieve by doing it, and whether it is worth it to them. Finally, it is not difficult to find good information online that explains what many of the various features and tolerances associated with precision weighing equipment really mean in practical terms; for example, readability, accuracy, linearity, etc. If someone is going to spend their hard-earned money on weighing equipment, it only makes sense that they take a little bit of time to learn something about that equipment.

As to where any of these tolerances fit into the grand scheme of things, I'm going to let people figure that out for themselves. It's simply not that difficult. For example, moderate to medium wind conditions in a typical F-Class match at 600 yd might be worth as much 2 to 3 MOA deflection, or perhaps even a bit more. Wind is usually by far the largest source of error. So one needs to figure out how wind deflection might compare to something like the difference between a load that reliably shoots 0.25-0.3 MOA at 100 yd, and one that reliably shoots 0.15-0.2 MOA. Over the long strings of fire we shoot in F-Class, the fact is that you're probably not going to notice any difference in those two loads in terms of score when the wind comes up. In other words, the wind is likely to be a far greater source of error than piddling little differences in group size during load development at short distance. Along the same line, one needs to have some estimate of the level to which they can reliably make wind calls. All these little estimates and fair/reasonable assessments of our skill level and shooting equipment are essential to determine with some degree of certainty, or at the very least to make an educated guess, as to what our limiting sources of error really are. In order to minimize a limiting source of error, one must identify it first. So having a good toolkit for estimating and comparing potential sources of error is something every shooter should be thinking about.

 

[JFrank]

Is there a point of diminishing returns when it comes to powder weighing ?

The smallest increment is the weight of one granule. The weight of granules is not identical - by definition powder charges are not identical even if the scale says so.

To what degree is it necessary to control powder weight for a particular caliber in a precision discipline like 1000 yard benchrest ?

I still don't have a clear understanding of how the variation in the weight of primer compound - not the weight of the primer - is able to skew results even when powder is dispensed to 1/100 of a grain, but I do believe it contributes to variance even if powder charges are identical.

When do enviromentals have a bigger effect than powder charge variation ?

Run a ladder test at a thousand yards and you will quickly see how wide your node is, some can be a small as .1 grains and in a 1k br rifle ( 6mm for example) we use Varget or H4895 that equal about six kernels so it’s easy to see that .1gr sensitivity isn’t going to work very well.

 

[Skeetman59]

I bought one!! It works as advertised!! Mine does not drift!! Great scale for $299!! wheelgun7360

So did I.

 

[boltman13]

I believe Ronald Regan first said it, "trust but verify". Once I have calibrated my FX-120i and zeroed it I use profesonal grade check weights to verify the scale is weighing accurately. So far it has not been off, but I still verify before each session.

 

[big5ifty]

...see how wide your node is, some can be a small as .1 grains and in a 1k br rifle ..

I would not bet the farm on a 0.1 grain node, which is not a node, more like a point.

A mild change in ambient temperature is going to cancel that 0.1 grain node.

 

[MarkO76]

In regards to beam scales, I've seen people add 1 single kernel and change the balance on the indicator. It seems to me (and I could be wrong) that if you had a smaller line on the indicator, you could get a more precise weight. Am I correct in my thinking?

 

[JFrank]

I would not bet the farm on a 0.1 grain node, which is not a node, more like a point.

A mild change in ambient temperature is going to cancel that 0.1 grain node.

It’s a tough bet but one we have to decide on if we want to shoot small groups, when you do enough ladders at 1000 yards you’ll see the wide node you brought with you get real small real fast.

 

[Mikey_P]

Something else you might consider in the interim would be the Gem20 scale (https://www.amazon.com/Smart-Weigh-...ocphy=9024595&hvtargid=pla-304071963067&psc=1). These can be purchased for less than $25.00

Just purchased a Gem20. Couldn't pass it up as it's currently on sale for $19.00(!). Thanks, Ned, for the link.

Mike

 

[1066]

In regards to beam scales, I've seen people add 1 single kernel and change the balance on the indicator. It seems to me (and I could be wrong) that if you had a smaller line on the indicator, you could get a more precise weight. Am I correct in my thinking?

Most good beam scales will react to a single kernel of powder - the problem is, you just cant see it. If you think about the old traditional laboratory balance, the distance from the fulcrum to the pointer is, maybe 10-12", meaning a little movement moves the pointer a greater distance, with the average reloading scale the beam is only around 5-7". The Lee scale is actually very sensitive but this advantage is lost by the very short moment length, the reloading scales with the longest beams are the old RCBS 304 type scales, the Lyman M5 and the current RCBS M500, however with a simple USB camera or phone camera this small movement can easily be seen.
This little video shows five individual kernels of Varget being dropped into a 502 scale for a total weight of about 1/10th grain. Unfortunately, during some youtube shake up the annotations were lost.

 

[MarkO76]

Most good beam scales will react to a single kernel of powder - the problem is, you just cant see it. If you think about the old traditional laboratory balance, the distance from the fulcrum to the pointer is, maybe 10-12", meaning a little movement moves the pointer a greater distance, with the average reloading scale the beam is only around 5-7". The Lee scale is actually very sensitive but this advantage is lost by the very short moment length, the reloading scales with the longest beams are the old RCBS 304 type scales, the Lyman M5 and the current RCBS M500, however with a simple USB camera or phone camera this small movement can easily be seen.
This little video shows five individual kernels of Varget being dropped into a 502 scale for a total weight of about 1/10th grain. Unfortunately, during some youtube shake up the annotations were lost.

Maybe I'm wrong, but it seems like for 99% of shooters there isn't that big of a difference between a good quality beam scale and a good quality electric scale. Both are very sensitive and both are repeatable. Maybe the biggest difference is speed? I mean a good electric scale with the motorized powder thrower and trickler vs a beam scale. I would think the electric would win out for speed and accuracy, would it not?