Single stage press vs. progressive?

Tomochan, if you have a chargemaster holding +/- 0.1gr, you have a gem and super lucky.

Of those, I and others have tested, the variations is usually 0.2gr or higher. One would throw 1/2gr out now and then (high and low). If you increase the number of charges weighed, you will start to bump into these "flyers".

Does it matter? only you, your rifle and your target can decide.

I have proven way too many times how precise charge weights matter more then many reloading steps. Weighing each charge is painful but driving a bunch of 5's and V's makes it all worthwhile.

Jerry
 
Mystic Precision said:
Tomochan, if you have a chargemaster holding +/- 0.1gr, you have a gem and super lucky.

Of those, I and others have tested, the variations is usually 0.2gr or higher. One would throw 1/2gr out now and then (high and low). If you increase the number of charges weighed, you will start to bump into these "flyers".

Does it matter? only you, your rifle and your target can decide.

I have proven way too many times how precise charge weights matter more then many reloading steps. Weighing each charge is painful but driving a bunch of 5's and V's makes it all worthwhile.

Jerry
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Everything you say is correct though I might add that consistency of neck tension is probably equally important and, yes, I think I lucked out with mine but I am now hankering after a two decimal place replacement. Search for perfection never ends.
 
BadAsMo said:
Now 've never had the inclination to try, but from what I've heard, it is not possible to shine up a turd.

Clearly kombayotch you have never owned or so much as tested a 2 or god forbid 3 decimal place scale, or you are a short range shooter and would not know the difference.

I have personally owned 4 scales, Dillon 1 decimal place, RCBS 1 decimal place, Sartorious 2 decimal place and Vibra 3 decimal place (meaning grains as a unit of measurement). I have compared them all and I could type until my fingers hurt about all the ways ALL 1 decimal pace scales are only good for short range shooting. I have tested the loads and the velocity spreads that result from variations in said loads. Out to 300 yards you could hardly tell a perfect load from a powder scoop. At 600 yards it matters and at 1000 yards in means everything.

The real variation of a 1 decimal place scale is plus or minus .2 grains, meaning a .4 grain variation in the loads. Don't confuse a precise number being displayed on the scale with a precise weight on the pan.

It is not possible to consistently hold 10 inches of vertical at 1000 yards with a 1 decimal place scale under the most ideal conditions.

My Vibra scale can weigh the ink it takes to sign your name and that is no BS, or you guys can line up with our boy kombayotch.

There are plenty of decent 2 decimal place scales for around $300, just google it.

This company sells more than their web site shows. You just have to call them. They have scales from about $150 to $2000 so pick what you can afford. Also they are Canadian.
http://www.walterproducts.com/products-main/balances/electronic-balances/kilotech-kha-series-entry-level-precision-balances

One more thing, make sure the model you pick weighs in grains. Don't confuse G as in Gram with Gn as in grains.
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No, it isn't going to hold up to a high end 3 decimal place lab scale, but neither is your Sartorious (formerly called Acculab, which as I said, I have owned) unless they have improved them significantly as of late. I doubt they have since the review on Sinclair are still low, and state that they still drift all over the place. Everyone I know who has owned one has replaced it with a Denver TR-603D (or similar). The Acculab/Sartorious was no better than a beam scale or many of the 1 decimal place digital scales or the Chargemaster once it was tuned, had reducers installed and when bad charges were dumped back into the hopper. That is comparing them on the TR-603D and comparing the SDs of the ammo. If you spend $300 on those 2 decimal scale, you're wasting your money.

Oh, and you can leave your attitude at the door unless you'd like to end up in the pink. ;)
 
Tomochan said:
Everything you say is correct though I might add that consistency of neck tension is probably equally important and, yes, I think I lucked out with mine but I am now hankering after a two decimal place replacement. Search for perfection never ends.
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I just bought 3 AND F X 120 i for 400 beans each from toronto I think, they had a special one as the school boards cancelled out on orders for (1000 each in the USA) Ontario I think and they are great, hoold to 2 / 100 ths of a grain plus or minus and sem not to drift,


the special ends end of may I think cannot remember who we bought them from http://cambridgeenviro.com/productD...-A-D-5-Year-Warranty-Top-Loading-Balance-2867


I cannot shoot worth crap but have nice chit

Jefferson
 
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back40sniper said:
I look forward to the day I can call wind good enough at 1000+ that a +/- tenth grain is as important to me as it is to some people. I salute you and aspire to these levels, cheers!
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Nailed it.

Even 3/10ths of a grain aint gonna make a lick of difference at 1000 if you miss the wind.

I have been loading on my tuned Chargemaster for 4yrs (double checking each load with my beam scale) and I seem to do OK out to 1000yds/900m against the competition. I even manage to win a match or 2 along the way.
 
In process engineering we have a problem that we refer to as “Tolerance Stack Up”.

Tolerance Stack Up is exactly that… the end result of a series of tolerances once you add them all together.

For example, if you had a staircase built consisting of 5 steps and you told the carpenter that each tread had a tolerance of 12 inches, plus or minus 1 inch, the total length of the stair case could be anywhere from 55 inches to 65 inches long.

This same concept can be applied to reloading and shooting…

The muzzle velocity of your ammunition is driven by the sum total of all the variables within the load itself. The more you reduce the variation of each variable the more you can reduce the sum total of all of them as applied to ES and SD.

So what are some variables?
1) Brass fit to chamber (fire formed or FL resized)
2) Neck Tension
3) Bullet weight and dimensional variation
4) Hardness of brass
5) Variation in brass weight
6) Primer consistency
7) Consistency of seating depth
8) Powder charge
9) etc

So yes, the powder charge is only one of these variables, but to dismiss it as irrelevant is a mistake.

To minimize the importance of one variable simply due to the existence of all the others is absurd.

To create ammunition that is as consistent as possible we must address all the variables one by one to the greatest extent we can within reason.

So if we load the best ammunition we can and we have a good accurate rifle, the shooting is all up to the nut behind the butt. The thing is that it does not matter how good of a shooter one may be if the ammunition is not consistent, it will play out on the target.

When a round goes high or low you need to KNOW why so you can correct for it - or not. If it goes low due to a light powder charge you will have no way of knowing that at the time you make the shot, so you are left to guess if it may have been a light load or if a condition has shifted.

If your loads are precise, then you can rule out variations in the load and focus on external factors such as wind and mirage.

This is all basic physics and if you choose to cling to your chargemaster as the ultimate despite the obvious fact that better can be had by spending that same amount of money on a more precise scale then you need to think this through.
 
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kombayotch said:
http://www.6mmbr.com/gunweek059.html

About the Chargemaster; if you try and use it out of the box, without tuning it and not paying attention to what the display reads when you remove the pan, then yes its crap. However, it can be accurate if you tune it, add a reducer and make sure the display always reads -(pan weight) before dumping the powder. I had an Acculab VIC-323. The SDs I got from using it were no better. it was slow because it was always drifting all over the place (even on a UPS). My two Chargemaster keep the powder flowing as fast as I can seat the bullets and check the runouts.
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Reading this post, this is exactly what I'm hoping people new to reloading can avoid. I did the exact same thing. When you add up the cost of all these scales, you could have bought one really nice lab grade 3 decimal place scale.

A good 3 decimal place scale might drift from 0.000 to 0.004 grains before you need to hit the Tare button and that is not often. 0.004 is about 1/5th of the weight of a kernel of Varget.

In the end it is not the cost of the good scale that hurts. It is the collective cost of all the discarded scales added to the endless days and cost of dissatisfying experimentation at the range before the good scale was finally bought.

I normally recommend the Vibra brand scale (balance) to those who can afford it because the load sensor is a tuning fork which is not affected by dust and it is the least affected by variations in electricity. Magnetic force restoration models are likely to require periodic trips to the factory for cleaning if they get powder residue inside the sensing system. Load cell models are the least expensive but worst of all. Their accuracy degrades over time and usage and they are most susceptible to variations in electricity. Normally anything under about $500 will have a load cell.
 
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FX-120i ordered, thank's Jefferson for mentioning this great deal on them, I had been wanting one for some time.
 
Tomochan said:
I use a RCBC Chargemaster and my loads shoot pretty well when the driver is switched on but what BadAsMo is saying seems to make sense as on my scale a, for example, 46.5 reading could be 46.511 46.599. Such a variance wouldn't really show up until out past 600 or so but it would make a difference and such a difference would grow with every inch the bullet traveled.
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Actually I'm saying that when your chargemaster scale reads 46.5 the actual load weight might be anywhere from 46.3 to 46.7.
 
In Electronics Engineering, we have a problem known as "Signal-to-Noise Ratio".

When we look at signal-to-noise ratio, we compare the magnitude of source of noise to the magnitude of the signal. When trying to eliminate any source or noise, there reaches a point of diminishing returns. And if the noise is insignificant, we don't spend extra time re-designing circuits with more precise and more expensive components trying to eliminate it. There is a point where the error of your powder charge becomes a red herring. While an expensive 3 digit scale is a wonderful tool to have, people shot good scores before they were available.

We also have something called "Quantization", which is the voltage each bit the analog-to-digital converter reads represents. Weight placed on the scale is converted to an electrical signal by a transducer that is fed into the analog-to-digital converter. Each bit represents a voltage that is proportional to the weight the transducer is measuring. When we design something like an electronic balance, we like to make sure that each digit in your LCD display is represented by several bits of information. Therefore, the scale can actually measure at a higher resolution than what is displayed to the user. And while the user cannot see that information, the internal microprocessor can. So, when something is being trickled onto the scale, the processor can measure it at a higher resolution than a user reading the display can.

Another interesting concept is "Hysteresis", which is the memory inherent in both electrical/mechanical systems and material. An example is when you bend a wire, you need to bend it back further the other way in order to get it back to its original location. We know that strain gages have much higher hysteresis than one that magnetic force restoration, which is why they have a tendency to drift more. We know that the cheaper (if $300-400 is cheap) 2 digit scales use the same strain gage based sensing technology as the cheaper 1 digit scales (including the Chargemaster), so they aren't necessarily capable of higher accuracy, they're just displaying more decimal places of the same signal. So some of us don't waste our money on more expensive strain gage based 2 digit scales that still display a lower resolution of the signal than what the Chargemasters internal processor is measuring.

I don't know why people insist on flashing engineering credential as if it will automatically make them right. Many of us here are engineers and spend our work days arguing with other engineers. So, not all of them can be right...
 
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BadAsMo said:
0.004 is about 1/5th of the weight of a kernel of Varget.
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So what tool do you use to crop those kernels of Varget into 5ths ?

Not trying to pick one here but honest to gosh, I just don't get it. In a "diminishing returns" world, there surely has to be some point where good enough is good enough. We measure velocities on equipment rated at +- 0.5%. Are we playing "pick-up-stix" with our butt cheeks ?
 
BadAsMo said:
Actually I'm saying that when your chargemaster scale reads 46.5 the actual load weight might be anywhere from 46.3 to 46.7.
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And you're missing something very basic in doing so. Your empty pan has a weight. You can measure that weight. When you remove the powder pan, the display should read negative that weight. It should do so because you tared the scale with the pan on it. If it does display that, your weight measurement is consistent. For it to display that and not be consistent, you would have to have a drift in BOTH offset and gain that would put your other point (powder weight) at the same location. Possible? Sure. But, statistically very unlikely. This is why you look at the display when you remove the pan. If it does not display -(pan weight), then don't dump the powder into the case, dump it back into the hopper. Yes, your initial weighing may be off, but the measurements will still be consistent, at better than +/- 0.2. That is what you get from the CM out of the box, without taking any precautions.

Sure, a 3 digit magnetic force restoration scale is a wonderful tool to have... IF you can afford it. But it is not absolutely necessary, people got by without them for a long time and few people using them today have beaten the scores of yesterdays good shooters that didn't have them. My point was that the Chargemaster is capable of the same accuracy as other strain gage based scales (including the 2 digit ones) IF you take some precautions. The most notable being to limit the powder flow so that you don't get clumps during trickling, another being to deal with the static buildup issue that seems to plague the plastic they use on it.
 
back40sniper said:
I look forward to the day I can call wind good enough at 1000+ that a +/- tenth grain is as important to me as it is to some people. I salute you and aspire to these levels, cheers!
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You beat me to it. I wish I was that good where being that anal would actually make a difference when shooting long range.
 
kombayotch said:
And you're missing something very basic in doing so. Your empty pan has a weight. You can measure that weight. When you remove the powder pan, the display should read negative that weight. It should do so because you tared the scale with the pan on it. If it does display that, your weight measurement is consistent. For it to display that and not be consistent, you would have to have a drift in BOTH offset and gain that would put your other point (powder weight) at the same location. Possible? Sure. But, statistically very unlikely. This is why you look at the display when you remove the pan. If it does not display -(pan weight), then don't dump the powder into the case, dump it back into the hopper. Yes, your initial weighing may be off, but the measurements will still be consistent, at better than +/- 0.2. That is what you get from the CM out of the box, without taking any precautions.
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Ok I’ll bite.

When I tested my RCBS and Dillon scales (mine and other local and provincial shooters) I gave the scales every opportunity to produce the same repeated value. I weighed and re-weighed the same powder charge multiple times to ensure I was getting the same value each time. In between each re-weigh I used a length of wire as a check weight that weighed the same as the powder charge plus the pan.

I loaded 20 loads from each scale and then compared those powder charges on my Vibra 3 decimal place tuning fork balance.

The results were a total extreme spread of at least +- 0.2 grains on all one decimal place scales tested.


kombayotch said:
Sure, a 3 digit magnetic force restoration scale is a wonderful tool to have... IF you can afford it
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To this I say, you can. Just sell off the 3 scales you mentioned and you will have the cash to buy the better scale. Check out that FX-120i – that’s a great deal.

kombayotch said:
But it is not absolutely necessary, people got by without them for a long time and few people using them today have beaten the scores of yesterdays good shooters that didn't have them.
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I shoot F Class and the V bull has recently been reduced from 1 MOA to ½ MOA because people are shooting much better than in the past. Tie breakers at the provincials would go on for 30 rounds on a 1 MOA v bull. Now that we are down to 1/2 MOA, ties are much more rare.

kombayotch said:
My point was that the Chargemaster is capable of the same accuracy as other strain gage based scales (including the 2 digit ones)
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No argument. I always recommend something better than a strain gage. Again – see FX-120i – at 400 bucks that’s a no brainer.
 
HKMark23 said:
So what tool do you use to crop those kernels of Varget into 5ths ?

Not trying to pick one here but honest to gosh, I just don't get it. In a "diminishing returns" world, there surely has to be some point where good enough is good enough. We measure velocities on equipment rated at +- 0.5%. Are we playing "pick-up-stix" with our butt cheeks ?
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I don't cut kernels, but I must admit that at times I am tempted to. At least with my scale I have that option.

On match loads I am satisfied with loads that range from my exact target weight to that weight plus the weight of one kernel. So if I want 45 grains of Varget, I settle for loads of anywhere from 45.000 to 45.020.

If I see a load that weighs 45.022 I will pick out one small kernel.
 
When I come across at $400 magnetic force restoration scale, that I've seen credible test results for, I will snap it up. The description of the FX-120i on some of the sites selling it states: "If you are an obsessive competition shooter and need powder weight to the absolute kernel then you probably need to buy the Sartorius GD503."

If you're going to be obsessive, you might as well go the length...
 
HKMark23 said:
So what tool do you use to crop those kernels of Varget into 5ths ?

Not trying to pick one here but honest to gosh, I just don't get it. In a "diminishing returns" world, there surely has to be some point where good enough is good enough. We measure velocities on equipment rated at +- 0.5%. Are we playing "pick-up-stix" with our butt cheeks ?
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Point of dimishing returns. You are absolutely correct that most rifles can't show you 1 or 2 kernels of varget so that degree of error is lost in the "noise" of the rifle accuracy.

BUT, when a scale has a variation of +/- 0.2gr, that is still only a handful of kernels of Varget (each kernel is 0.02gr by the way). So 4 to 5 kernels is 0.1gr. That is not alot of powder and most just disregard that itty bitty bit as important. Add that error, to other errors in the loading process and you have a stacking error that will show up on paper.

By the way, for competitive 223 loading, you will be able to see 0.1gr on target at LR.

Whatever scale you presently have (as long as not some really nice mag force scale), compare to a "better" product so you know what the true error rate is. ALL measuring devices have a range of error - there is no perfect device. The key is using a device whose error is SMALLER then what you are trying to measure. There is no point in cutting kernels of powder.....

Example - I use a Gempro250. This is a strain gauge 2 decimal digi scale. Quite inexpensive and drifts. It is fast for a reading and you just have to learn its quirks (this is not a no brainer scale). The manf error lists as 0.02gr so it offers the MECHANICAL accuracy of under 0.1gr which is all that I care about.

Assuming the scale is working, the worst I am going to be out is 2 to 3 kernels of varget from case to case. THAT is plenty close enough even if trying to hit a pop can at 1000yds.

I will say that until you load your ammo with a scale capable of holding error to under 0.1gr, you will never really know how out of tune your load truly is. It became real clear when I switched to these scales to load my 223 ammo.

For a 308, some will show variations as small as 0.1gr but definitely 0.2gr. When you load to that level of consistency, the shape of your groups WILL change.

Round groups are a great indicator of a shooter using a scale with a higher error range (assuming all other loading steps are done well) .... or one that needs to practise their follow through a whole lot more :)

Jerry


Just scroll through the video to speed it up. At 500m with my 223 FTR rifle. What good load tuning and accurate scales can do for you
 
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"...any reason you can't..." Nope, but it's not going to be as precise as ammo you've weighed each charge, etc. Progressives are about loading lots of good enough ammo fast. They ain't exactly precise.
 
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