A Good Safety Lesson

[chrishayes]

I only use a beam. Ohaus in this case. My partner bought a $25 digital and brought it over. Took 4 mins to decide this thing is going back. Ghosts in the ethers won't effect a beam scale. My beam will settle on a measurement in ~4 seconds. A digi scale just is not that much faster.
I always use my Dillon powder drop and it's spot on barring stick powders like 700X and 800X. So now I only use Longshot in rounds that other stick powders might be applicable.

 

[DartonJager]

Just my 30 year experience. I bought a PACT digital powder dispenser and scale for rifle reloading 30 years ago. Have two made for RCBS Ohaus 1010 beam scales and one 505. I checked every PACT powder charge with my 1010 and before every reloading session check my 1st 1010 with the second 1010.
I read that PACT offered a upgrade to my powder dispenser that would make it 2x as fast and I had it done.

That was 10 years ago. I have since used it to reload countless rifle cartridges in 223, 7mmstw, 308win, 300wsm, 300wm, 6.5x55 Swede and of late TONS of 450 Bushmaster and 35 Remington. After throwing countless thousands of charges and measuring 1000s of them I have determined my PACT at times is off by a VERY consistently .2 grains NEVER more or less always .2 grains so I have it throw charges .5 grains light and trickle up to my needed charge weight. Not kidding it is actually kinda bewildering its ALWAYS 0.2 grains never more or less and that's using all three of my balance beam scales as checks.

My reloading room is in my basement and my bench is rock solid dead level and plumb and I use only incandescent lighting and no breeze of any kind is ever present and no other electronics are in my basement or in reloading room or in use in my basement when I reload.

I use a optical chronograph while developing all new reloads and never have experienced anything even approaching a significant deviation in the velocity of my reloads that would suggest even a minor inconsistency in powder charge weight.

I can say with complete honesty I have RELATIVE to its cost, enjoyed excellent consistent accuracy with my PACT electronic scale and powder dispenser.

Forgot to add the area of my bench where my PACT sits is covered by a very hard mat that is made to be anti-static and will not conduct electricity we use in my industry that are placed on the floor in front of low and high voltage electrical switchgear as safety precautions.

 

[venomballistics]

After weighing a bullet with a primed case on the scale to get a baseline, I weighed each of my five loaded cases one by one. Once doing the appropriate math, I found the powder across all cases varied from 2 to 9 grains over what .....

This will have told you something next to nothing.
Runout of your brass and bullets can easily account for 2 - 9 grains.
You will need to pull the bullets and weight the powder directly.
There's almost no way to overcharge by 9 grains and still have your bullet fit

 

[rockquarry]

This will have told you something next to nothing.
Runout of your brass and bullets can easily account for 2 - 9 grains.
You will need to pull the bullets and weight the powder directly.
There's almost no way to overcharge by 9 grains and still have your bullet fit

I don't understand. How does runout (concentricity, I'll assume) account for 2 -9 grains (of what)?

 

[venomballistics]

I don't understand. How does runout (concentricity, I'll assume) account for 2 -9 grains (of what)?

Weight variation if you prefer.
The op weighed loaded rounds expecting to determine powder charge of those rounds.
How's everyone missing this?

 

[rockquarry]

Weight variation if you prefer.
The op weighed loaded rounds expecting to determine powder charge of those rounds.
How's everyone missing this?

I'm certainly missing it. Runout and weight variation aren't even closely related. Two very different aspects of handloading. I've never heard of runout with pistol brass, but maybe it's possible. I have a Sinclair concentricity tester, the least used tool on my loading bench. I'll try it with pistol ammo and see what I come up with.

 

[Neumann]

Time for me to read up on tolerance stacking! It will be a good consideration for the future.

There was a fluorescent light in use in the garage, so that certainly may have been interfering with the scale. I will start noting the variables and see what I can do to control things. I want to see if I can get the digital scale to be reliable.

If you know the weight variations of each component, the net variation is described by the Sum of Variances (variance = (standard deviation)^2). As someone else said, the best you could learn from weighing the loaded cartridge is a double charge, and I wouldn't trust that. Pull all the bullets and dump the charge. For grins, check each charge weight. At least you can reuse the components, except for belling, seating and crimping. Dump the powder or recycle, it's up to you.

If you have a gas furnace or water heater, cold makeup air will flow across the floor.

I use a progressive press, and check each powder dump until three successive weights are within 0.2 grains. I do that on startup, and after any significant interruption. If the scale were wacky, you would see greater variations.

 

[rwsmith]

One last thought,
Weighing loaded cartridges doesn't tell you much. It's called tolerance stacking....

Agreed. This doesn't really tell you anything. Re-weigh the powder after pulling the bullets.

 

[Mike SC Hunter]

I have a new RCBS electronic scale sitting in it's box on a shelf above my reloading bench......I'm still using my 40 year old RCBS(Ohous) 10-10 scale..........Iffen a balance beam scale scale ever goes out of whack......You can remove the silver pan that the powder pan sits on......Remove The screw and open. Add-subtract #8 lead shot to recalibrate it.

 

[rockquarry]

I have a new RCBS electronic scale sitting in it's box on a shelf above my reloading bench......I'm still using my 40 year old RCBS(Ohous) 10-10 scale..........Iffen a balance beam scale scale ever goes out of whack......You can remove the silver pan that the powder pan sits on......Remove scale screw and add-subtract #8 lead shot to recalibrate it.

I've never had that problem with any balance beam scale, but that sounds like a good idea.

 

[Rick H.]

An interesting thread with good information, but I can't sit in the dark ages when reloading. A few years ago I was using an RCBS electronic powder dispenser and it worked well. I just had to keep an eye on the display as I went thru the process of charging cases and constantly check it with my beam scale. I read about and saw an Auto-Trickler setup that uses a A and D Company FX-120i scale. Auto Trickler is made by a Canadian company and they are making later versions of this scale and powder measure. The one I have is a V-3 model and it works very well and measures to 100th of a grain. You just have to follow the directions for use and setup. They are now making a V-4 version that is supposed to also work very well with several improvements to the V-3 design.

The Auto Trickler and A and D scale combination I have has given me no grief at all save for the sensitivity of the scale. Air temperature, wind or drafts and even humidity can have a slight deviation on powder drop readings. After a few uses I discovered the most ideal location for this dispenser and scale in my reloading area, but there are times when my scale will pickup a .1 to .2 tenths positive reading from "0". Usually this is when I stop the powder drop process for more than a few minutes, but the Auto-Trickler will not allow a powder drop if the scale doesn't read "0". In other words, it is designed with its own fail-safe program. No "0", no drop. The scale is dead nuts accurate when compared to my RCBS beam scale.

I was a bit concerned when I bought this scale and dispenser from CE products, which is their USA distributor, as I am not a very techie guy. The setup process went well enough, but I did have some questions that were answered via email in very short order. Their customer support is terrific. I did buy some spare parts for mine as the V-3 model is no longer made, but those parts are sitting in a box unused. At the time I bought this dispenser and scale I think the price was about $900.00. I know that sounds like a lot of money, but it was money well spent for speed in powder dispensing and accuracy. I have yet to find a powder that doesn't dispense well thru this dispenser. Powders like Varget tend to clump granules, so you may go over your indicated charge weight, but only by a few hundredths of a grain.

I can't say enough about the Auto-Trickler and its use. If setup properly I can charge 45 to 50 grains of powder in about 8 to 12 seconds with no over charges. The V-3 drops a bulk charge and then the trickler kicks in to finish the pre-set charge weight. I still compare my drops from the Auto-Trickler to my RCBS beam scale, but not near as often as I used to. Setup properly and used properly this dispenser is a marvel of engineering. I am sure the new V-4 model is even better, but I don't know how it could be.

I must add that the Auto-Trickler doesn't like dropping very small powder charges using the bulk dispenser. It doesn't adjust low enough for anything under 10 grains or so. For those types of loads I just use the trickler sans the bulk dispenser and this works very well doing so. Even just using the trickler by itself I still get dead accurate powder drops in about 10 or 12 seconds.

Since the Auto-Trickler has come out there are a few other companies that have come out with their own versions of this product. Some are quite fancy with cabinets and fancy lighting and I am sure they work well enough, but I trust what I have and have no intention of making a change. If mine broke permanently I would no doubt buy the V-4 version of the Auto-Trickler. Yes, it is that good!

Rick H.