Cause and effect

[VandelayIndustries]

I thought itd be interesting to do a cause and effect thread to help reloaders of all skill levels figure out what went wrong and why. So for example when I first got into reloading a mistake I made was having the shoulders of my resized cases bulge just after running them trough my seater die. It was caused by not backing my seating die off enough during initial setup. Another is from a podcast I listened to where they talked about how having a carbon ring can cause you to pull bullets.

 

[Doom]

Good idea if the posts stay on subject. The post should also give some explanation of “why” the problem occurs.

The bulged case you referenced can occur with seating dies that have the ability to taper crimp the case into the cannelure of certain bullets. To set up the die for a crimp is a 3 step process. To seat without the taper requires only running the die to the shell holder then backing it off enough to keep the taper portion of the die clear of the case mouth. It is important to read ALL of the instructions for the seating die before setting it up in the press. If

In the case of Lee seating dies there are two different dies, one that will crimp and one that is call a Dead Length Seating Die.

 

[SERE8541]

When I first started, I thought only military brass was crimped. I later found out that is NOT the case. FC and Speer nickel are a couple of examples of crimped brass (.223 speaking). So, I over swaged a bunch of the Speer. The result was I blew out a bunch of primers and ruined the cases. Another result was some of the primers fell down below my trigger in my AR and jammed the trigger. I had to dig them out. What I learned was not to over-swag brass.

 

[918v]

One of the problems with reloading equipment is that it is often way too powerful for the task. For example, seating primers with a press mounted attachment. Or seating bullets using a die in your big press. They are not sensitive enough to give the novice the necessary feedback to sense something isn’t right. The results often are blown primers and damaged bullet tips or bullet setback.

 

[Rocketmandb]

seating primers with a press mounted attachment. Or seating bullets using a die in your big press.

Right on point with this one. Very inefficient to move the whole ram and case to seat something that only needs to move fractions of an inch. It introduces unnecessary error and, as you mention, takes the feel out of it.

 

[tomme boy]

Your brass has to be all the same length also when it comes to crimping in standard seating dies. It will buckle the shoulder if you have long pieces.

 

[338dude]

One of the problems with reloading equipment is that it is often way too powerful for the task. For example, seating primers with a press mounted attachment. Or seating bullets using a die in your big press. They are not sensitive enough to give the novice the necessary feedback to sense something isn’t right. The results often are blown primers and damaged bullet tips or bullet setback.

Leverage

 

[Doom]

My electronic/digital scale drifts? Why?


The answer is ALL scales drift. Some more than others. They should be installed and set up according to the manufacturer’s recommendations to provide repeatable results and eliminate errors and minimize drift. The scales used by reloaders are typically precision scales of varying quality and price but they all consist of two major systems. The primary element is usually a load cell that generates a voltage output proportional to force (weight in this case). The output of this load cell is very linear but the charge in voltage is extremely small. It is also self-compensating for temperature in the normal temperature ranges it is used in.


To be useful the output of the load cell is fed to a very high gain electronic amplifier circuit. This is a multi-component system with components that have both linear and non linear responses to changes in temperature. Because it is high gain, it is very sensitive to temperature. This temperature dependence has a minimal effect on the amplifier gain but does tend to bias the “zero” reading. One of the primary performance specifications for an electronic component is its performance versus temperature. The better the performance the higher the cost. The grading of electronic components is very similar to quality sorting of 22LR ammo such as Lapua or Eley.


To understand drift it helps to understand how the scale measures weight. When a scale is calibrated, it will use two or more datapoints to establish the variation in cell/output to weight. The calibration should be performed with the platen empty, this is without the weighing pan. For those that remember algebra the equation of a straight line is y=mx+b where m is the slope of the line which is the variation in voltage with applied weight, and this slope is determined during calibration. The scale then uses the 0 calibration point as the initial zero/tare reading ( b in the formula) to adjust the reading to zero. Once the pan is placed on the platen a new tare is calculated when the zero/tare button is pressed.


Temperature is not the only source of drift for a scale. Hysteresis of the load cell occurs. This happens when the zero is approached from different directions and is also dependent on time. Placing a heavier weight on a scale will require a longer amount of time for the scale to return to its “zero” condition.



Good laboratory practice is to re-zero the scale BEFORE EVERY SAMPLE IS WEIGHED. This is a step that is often omitted by reloaders. RE-ZEROING eliminates the potential drift issue and is a common automatic feature on higher end scales such as the Fx-120i and the Chargemaster 1500. In some cases, if trying to measure very small weights near zero the auto zero function interferes. The scale sees the minor changes in weight as zero drift and re-zeros.



It is also important to understand that the scale does not use a single point reading but averages readings over time. Not providing enough time for this to occur can also be a source of zero AND weight reading errors.

 

[JoshPutman]

Something else I've learned about electronic scales is to leave your cell phone away from them, and florescent lighting can make them act wonky.

There are other things that make them act goofy, I'm sure. These are just a couple I've learned.

 

[Whiskey Tango Foxtrot]

I wrote on the powder hopper on my chargemaster,
CLOSE DUMP
only happened 1 time

 

[6.5SH]

I wrote on the powder hopper on my chargemaster,
CLOSE DUMP
only happened 1 time

I use a rubber band to hold it closed and give a visual cue on mine.

 

[acudaowner]

not that it's something anyone else has to do this , but I made my self a check list to follow step by step check list on a 3x5 card of what needs to be done to the brass just so I can't forget a step while getting my brass ready to be fired again . One of them follows each box of brass I am working with it also gives me a better way than just remembering ( ha) in my head how many times each box has been reloaded . the ones that follow the ammo around and get checked as I do a step were laminated so it just a wipe clean and reuse item .

 

[Haney]

Something else I've learned about electronic scales is to leave your cell phone away from them, and florescent lighting can make them act wonky.

There are other things that make them act goofy, I'm sure. These are just a couple I've learned.

When you say they act Goofy ,what actually happens to the scales ? Thanks

 

[JoshPutman]

It's been quite a while, but from what I can recall, you could watch the readout bounce around when you were weighing a charge, or get vastly different readings between throws that were actually the same weight.

 

[Trapshooter12]

I always leave the container of the powder I am using next to my scale so that there is no confusion as to what powder is in the scale.

 

[cat-mechanic]

Don't try to cram large pistol primers into small pistol primer holes. I didn't know 45 ACP had both, until I found out the hard way. Have since learned that 10mm has both as well. Bastards. On a positive note, Dillon will replace the entire priming assembly when this happens and you end up igniting your primer stack.

 

[OkieMike]

It's been quite a while, but from what I can recall, you could watch the readout bounce around when you were weighing a charge, or get vastly different readings between throws that were actually the same weight.

I run fluorescent lights in my shop and haven't had an issue. But when I remodeled I made sure everything was properly bonded and grounded.

I'm not an electrical engineer so I don't know if grounding makes a difference... But IIRC the modern electronic ballasts change the frequency to eliminate the flickering the old magnetic ballasts were prone to. Anytime you go through the process of changing frequency you have the potential to introduce wonky waveforms onto the neutral. That "garbage" may bleed over on to other equipment. A properly grounded and bonded system may help mitigate that... Or it may not. It could also be interference from a field produced by the light fixture itself. I don't understand what little I know about it.

I'm betting there's an EE on here who could shoot down my theory or verify it.

Mike

 

[VandelayIndustries]

I always leave the container of the powder I am using next to my scale so that there is no confusion as to what powder is in the scale.

I write the powder name on an index card and stick in the hopper. Same principle though.