Consistency applied.

[MBTcustom]

Thanks for the input popper. What you describe is exactly how I used to cast.

Unfortunately, for me, visual inspection is no longer sufficient to achieve my goals. My bullets were consistent in appearance, but closer inspection with the basic tools available to me showed a different story.
I decided that I wanted my bullets to measure exactly the same, weigh exactly the same, and look exactly the same. Judging by the groups I believe the effort at the bench is paying off for me.
Although I must confess I would prefer to cast bullets that are as perfect as I can cast as it pertains to the above criteria regardless of whether it made a huge difference on target or not. I may not be to the point as a marksman that I can detect subtle differences in bullets weight and diameter, or I may not be shooting at distances that it would make a difference, but I would prefer to be ready when that time comes, with good casting habits and proven processes.

[MBTcustom]

Bravo. That is how it's done, and it does not matter what alloy you use. Each one will have a sweet spot.

Just a little back story for the readers; sgt.mike and I worked on this together December 2013 and continued to work on it throughout 2014 to the present. We have plotted dozens of bell curves with all the alloys we have that are usable for casting a bullet out of. The results between the two of us were very consistent in that we always saw a sweet spot in alloy temperature. Also, we both improved greatly in our casting proficiency over 2014.
When we started this exercise late in 2013, my bell curves looked pretty much like sgt.mike's posted above. Where I am at now is clearly shown in the OP.

You too can enjoy this level of precision and consistency with the molds you own. It's exciting and rewarding to see where you are at, and to make a change and observe the result as sgt.mike was good enough to demonstrate.
Remember, it's not about the bullets. It's about the guy holding the mold, and this process will help you refine your process into a fine art.

My father once told me something that has always stuck with me and I believe it to be so: "There is no such thing as magic. Magic is just good science, badly explained".
This is simply using the power of observation to produce a repeatable technique.

Thanks for posting sgt.mike.

[Sticky]

Excellent demonstration sgt.mike! Thank you!

I will work on temps in a similar manner next time I can bear the garage cold for a while (very soon, i'm itchin..lol). I also need to get a hole in my molds so that I can monitor mold temp as well, I think that will be an enlightening facet of the process for me, as a new caster. I need to get a handle on these areas to increase my consistency. Thanks again for sharing! :cheers:

[MBTcustom]

Excellent demonstration sgt.mike! Thank you!

I will work on temps in a similar manner next time I can bear the garage cold for a while (very soon, i'm itchin..lol). I also need to get a hole in my molds so that I can monitor mold temp as well, I think that will be an enlightening facet of the process for me, as a new caster. I need to get a handle on these areas to increase my consistency. Thanks again for sharing! :cheers:

When you get the thermometer in there and start using it, just use it to see general trends at first. I made the mistake of thinking it could be used to replace the timer, which it cant. You have to plug it in and just keep an eye on it occasionally, and you'll start seeing a correlation between what it says, and what you are doing. I outlined the biggest benefits I have found in post #53, but I haven't been using this tool for very long.

Also, I work in an un-insulated garage as well. Just for the record, if you invest in a kerosene heater, it will absolutely run you out of there. Mine was an absolute life saver and much cheaper than the sunflower propane heater I was using in previous years.

[Sticky]

Well, I live in the subfreezing zone this winter and my kero heater has been dedicated to supplementing the fireplace to keep the heat pump from wearing itself out this winter on those days when just a fireplace can't do it, so the cotton duck coveralls serve two important purposes for me in the garage - make it just bearable and protect me from the hazards of molten lead! I know the cold environment is not working for me, but honestly, most of my casting will likely be done in the cooler months and that gives me more time to dedicate to range time in the warmer months. It's just too darned cold to enjoy range time when your bare trigger finger is getting numb from the cold (well, it is for me anyway). So I need to get a process that will allow me to cast in these cold temps with consistency, knowing that I can adjust that, if needed, as the temps rise and I find myself short on a boolit in the middle of the summer and need to fire up the pot again.

I understand your point. One of my early goals in this learning curve is to identify and try to quantify those more critical parameters that affect the consistency of the process and the quality of the finished product and both alloy temp and mold temp are two obvious parameters that fit that bill. I know I can use the dial on the Lee pot and the temp scale on the hot plate that I have, but having hard accurate numbers takes that one step further. I PID'd my Lee pot before I even turned it on, so I can have an accurate monitor for that part of the process and I want to be able to monitor my mold temp as well. I have a meter that will allow me to use a non-contact IR pyrometer, but I have learned over years of measuring temps, that this is not the best way. It is always more accurate and repeatable to use a probe in the metal (IN the metal, not against the outside of it) to monitor the temp of a metal object. Heck, even a small thermometer can be used for this if the fit to the hole is close enough.

The mold is preheated on a hot plate, but I haven't yet checked the mold temps to see if it is even getting to the temp that is indicated on the hot plate, nor even verified the actual temp of the hot plate vs indicated by the dial scale temp. I need to do this to give me accurate monitor of that parameter. For now, I have just been using the tried and proven visual monitors that guide you to that sweet spot (even though I really don't yet know what that sweet spot is.. lol)

I am going to drill a probe location and use my wire bead probe that allows free movement and manipulation of the mold, or at least the ability to spot check the temp by just inserting the probe for a few secs to find out. I have seen the signs of improper mold temps, from poor fillout and wrinkling, to frosties and smeared sprue cuts and have learned to 'time' the sprue frost to try and find a consistent cadence. I know it's much about the timing and less about the other details, but having more hard data to monitor and record will surely benefit the process and my learning.

[MBTcustom]

Sticky, remember what I said about hot plate temperature. Its better to err on the side of too hot than not hot enough.
Your casting conditions are going to make consistency very hard.
First, your spout will need extra priming in order to heat up (you might have to go 1.5 seconds).
Second, your mold is going to be cooling off so fast, you're really going to have to be johnny on the spot with your dwell time (if you dwell at all).
Third, any error in cadence will require you to return the mold to the hotplate immediately till you bring it back up above your maintenance temperature.

The good news is that once you get this dialed in perfectly, you should be able to cast faster than any of us. I wish I could experience what that's like for an afternoon. That would be a very interesting challenge!

Please keep us posted on your progress!

[MBTcustom]

Made a big difference in my reject rate. Did you mic some of the various weights to see if dia. variance was a big contributing factor to the weight difference? I understand Tim's reasoning, to minimize voids in the boolit, just don't think he will find them by weight segregation. I think they are related to what I call 'smily faces' on the boolits. Small 1/10" dia. wrinkles that I believe are caused by contaminate in the melt (or mould), I haven't found any particles but it apparently is a local freezing area. This is my suspected problem with eutectic alloys, not just Lino. They freeze in a very small temp band so there can be no 'migration' of air/junk.

popper, I know exactly what you mean about the smiley faces in the bullets. It concerned me too until I realized that the cause of that is that Linotype has the tin and antimony in perfect solution with eachother which renders a highly reflective surface. When I hold the bullet in front of my face and inspect for defects, I can clearly see a smiling face in the surface of the bullet.
This is nothing to be concerned about, and I personally believe it has no bearing on the accuracy of the bullets on target, but like the rest of what I have written in this thread, that is my opinion only, and I hold noone else to it.

[Doc Highwall]

Tim and Mike, what distance approximately is the sprue plate from the bottom pour spout that you are using?

[MBTcustom]

Tim and Mike, what distance approximately is the sprue plate from the bottom pour spout that you are using?

About 1/4", or as close as I can get it without dragging the puddle.

[MBTcustom]

On that note, I did experiment with different spout heights and I have never found a long throw to give consistency, and in fact, increases the chances of air bubbles being trapped in the bullets.
I keep the spout height at about 1/4" mainly because if it were any closer, I couldn't aim the stream any longer, and I find that giving up a little in the spout clearance area, to gain the ability to attempt consistency with aiming the stream, to be a very reasonable trade-off.

This issue is another that can be settled with the bell curves, and I confess I never really experimented with it, but I encourage anyone else to do so if you are so inclined.
As with all the rest of this: exercise control at several different levels. If there is a difference, then pick the best one. If there is no difference, then don't worry about it anymore.

What has surprised me up till now is how things that I really thought shouldn't make a difference actually do have a significant impact on consistency. In fact, I have yet to find a single thing that does not effect the bell curve somehow. In each facet of bullet casting, I have found there is a right way and a wrong way for me to attain consistency such as I describe.

[MBTcustom]

So today is casting day and I decided to focus on COWW straight up just to see how close I could get. Mold used was the 30XCB.
COWW is on my list of "good" alloy's but certainly not excellent, and this is why:

I ran the bell curves this morning to find the ideal alloy temperature, and found it at about 705 degrees. Unfortunately fillout was terrible due to the surface tension of this alloy so I bumped up another 10 degrees to try to aid the fill out and experimented with dwell times. I tried a 6, 10, 15, and 20 second dwell times, and settled on 15 seconds as ideal for maintaining a mold temperature of 450 degrees, and a 2.5 second puddle freeze.
I ended up casting 300 bullets like this, but there were many lube grooves with rounded edges, and worm trails etc etc etc. This is just a tough alloy to get good fillout with, and I found myself in a catch 22 where I could bump the temperature up and get better fillout, and blow my bell curve, or I could maintain the ideal temperature (a little on the warm side) and do the best I could.
I went ahead and plotted this bell curve with some of the bullets. I had about a .7 grain variance (terrible IMHO) and the curve clearly shows the alloy was a little bit on the warm side. This is why we add tin to the COWW fellers. Yes, it toughens up the alloy and makes pretty bullets, but the main thing it does is reduce surface tension, which tricks the alloy into thinking it's being used at a much higher temperature, while at the same time actually lowering the ideal operating temperature. Like using a slow twist barrel, it just makes sense to do the obvious thing to make your results consistent.

Again, notice the preference the mold had for erring on the heavy side?
Attachment 132557
That's telling you that the alloy temperature was too hot. This was one of the most interesting discoveries I made when doing this bell curve project. I always line the bullets up with the light ones at the top of the page and the heavy ones toward the bottom. If the curve error showed a preference towards lighter weight, the base of the christmas tree swings it's hips to that way, and it means the alloy temperature is too cool. If the alloy was too hot, then your christmas tree will swing the bottom towards the heavy side, but the point of the christmas tree will always pinpoint the ideal weight that the mold wants to cast with that alloy.
I think that's pretty neat.
I never read about anybody doing bell curves with their bullets before, and the two points I just made have certainly never been told to me.

[MBTcustom]

Thanks for your input popper.
So what do you recommend our readers do to increase their consistency? so far, what I have gathered is that you do not weight sort, you do not control temperature, you do not control timing, and your inspection process is completely based on visual observation.
I have demonstrated my proficiency such as it is, but I am very interested in improving myself beyond where I am now (as is everyone who comes to this site).
What would you suggest I do?
How can I progress?
How will I know I have progressed with my casting and not just my riflemanship?
How can I gauge my progress?
Please help us learn!
Thank you sir.

[MBTcustom]

Thank you sir, but perhaps we have a differance of opinion when it comes to consistency?
When I say consistency, I mean as measured with the tools I have available to me (that would be my scale, and my micrometer).
You have stated that neither of these tools are worth using in your opinion. That being the case, the only thing left is visual appearance of the bullets. Would you not say that visual appearance is a very subjective metric by which to judge proficiency, and/or to educate the inexperienced with?
If visual appearance is all you use to test your bullets for consistency, how do you know you have improved? Moreover, how can you teach someone else to improve?
And why would you be so adamant about ignoring the basic tools available to every reloader on his forum?
I'm very confused by your aversion to measurement and documentation, and the resultant improvement. What negative effect would these common tools of measurement have on the accuracy of the bullets? I am trying to wrap my mind around your casting philosophy, but it's not coming easily. Could you please expound?

[kbstenberg]

Goodsteel and Sgt.Mike I wish there was some way that I could express my gratatude for opening my mind on how to improve my casting tech.
The last long paragraph in post 91 opened my mind to thought I had never even considered!!!
And Mikes example of how he narrowed down the melt temperature preference. Clarified how to go about my own tests. Thank you so much Kevin

[MBTcustom]

Thank you popper. Honestly, I can't argue with any of that. Certainly as it pertains to pistol bullets (low speed at close range) or rifle bullets at less than 2000fps/120,000rpm at 100 yards.
No argument from me. However, I personally believe that at velocities of 2700fps+, at ranges of 200yds+, and with a group size goal of 1moa or less, and RPM approaching 140,000 these things do in fact make a difference.
I would be shocked if creedmoor handgun competitors do not care about the absolute consistency of their bullets and find a direct correlation between consistent projectiles, and consistent scores.

That said, I have stated repeatedly in this thread that I am not doing this to sort my bullets by weight. That is absolutely not why I posted this. For 99.9% of the shooters on this forum the weight of the bullets means very little, and sorting them by weight is an absolute waste of time (although, the harder you push them, and the more you expect of them, the more stringent you are likely to get about the quality of the actual bullets themselves).
However!!!!!!
I am advocating that a shooter can sort out his casting process by plotting bell curves based on the weight of the bullets. By using the bell curves to whip their process into submission, it is possible to reduce his/her cull rate to practically nothing.

Rather than hold people to a set regiment of casting that may or may not work for them depending on their equipment and it's similarity to the average, I am explaining a way by which each caster can teach themselves what works and what does not. This is not a way to trap someone into one way of doing something, this is simply teaching people how to observe their consistency with a scale, rather than a firearm (after all, a scale is a much less expensive way to measure than burning two pounds of gunpowder) and to see immediately what effect changes have when/if they make them.
Once a caster has matched their process "prescription" to their unique skills/equipment, they can learn to realize their best potential, and think for themselves, rather than blindly following a certain process. A caster who utilizes this method will do things in a certain manner, will understand why they do so, and will be able to explain why they do so, on demand, as I have done here.

I am a fan of self sufficiency, personal education, and self reliance. This method provides all three.

[boltaction308]

Goodsteel and popper

I have not had a chance to read everything on this thread but what have read has been very informative and eye opening, thanks and keep up the good work

[MBTcustom]

Goodsteel - I think if you are looking to find voids in boolits that would cause 'bad' boolits you might look into the devices used to check welds, paint thickness, etc. They work like sonar (TDA) to measure density. Might try a local body shop to test? Or oil field welders?

Thank you for the suggestion popper, but like I have stated many times, even though this process will find voids, the object is to never have them in the first place, which is why I am advocating using this process for testing the person running the mold, rather than the individual bullets that person is producing.
Culling bullets by appearance, weight, diameter etc etc etc, is only killing the ants. By directing this process at the person running the mold, you are sorting out the problems at the source. After all, the mold does not change from one drop to the next. The alloy doesn't change. The temperature of the alloy doesn't change. If you are experiencing voids, wild variations in weight, variations in diameter, or lousy looking bullets, it's not the fault of the mold or the pot, it's the caster that made the difference. No amount of shooting will change that, and no amount of casting will improve the results unless the caster finds a way to focus on his part in all this first and foremost.
This method shows voids, wrinkles, size and length variations, base fill out problems, rounded lube grooves, and just basic bad timing on the part of the bullet caster, but it doesn't really focus on any of them specifically unless the caster chooses to use it in that way. What this method does do, is demonstrate the overall casting consistency of the person running the mold, and shows improvement or lack thereof.
At the end of the day, there is no way that you can cast +-.1 grain strings of 100 bullets without you having done many things very very right.
In this way, the bell curve method is a catchall and will help a caster solve any problem he/she might be dealing with.
It is possible to tack down any one of the various ways of measuring bullets without capturing the others (you can have perfect bases but wrinkled bullets, good diameter with voids, good diameter consistency with weight variations etc etc etc.) but the only way they will all weigh exactly the same is if all these things are nailed down together.

So why is it that I call some of these things errors? What do I use as a way to judge what is right, and what is wrong?
Its actually very simple: Any characteristic that cannot be accurately reproduced in each and every bullet is an error. If it's not the same every time, then it will have an effect on group size at some point. Take that to the bank.

But it's the very nature of these "errors" that makes them able to be detected by this learning tool. The fact is, they are wrong because they are never the same, and the fact they are never the same is exactly why they will be caught by the bell curve, just as they will be caught by group size eventually. In other words, the only errors that this method does not catch (speaking of the caster or the bullets themselves if you insist on looking at it that way) are the ones that are always the same and very consistent. Of course, that begs the question: If an error is 100% repeatable, reproducible, and consistent, is it an error at all? I don't think so.

[Doc Highwall]

Tim, I think of consistency applied as prevention is better then cure.

This reminds me of someone who buys one of the fixtures that measures and straightens your loaded rounds by bending the loaded round, instead of figuring out what in their seating die set up is causing the run out in the first place and fixing it.

[MBTcustom]

Tim, I think of consistency applied as prevention is better then cure.

This reminds me of someone who buys one of the fixtures that measures and straightens your loaded rounds by bending the loaded round, instead of figuring out what in their seating die set up is causing the run out in the first place and fixing it.

Thank you sir. That is a great way to put it, and is exactly what I am saying.

I started the previous thread because there were several people who I noticed were plotting a bell curve for each and every casting session, and were just using it to find defects and cull them. I was trying to tell them that they might be focusing in the wrong place. Once the sweet spot is learned and written down, you are able to cast excellent bullets, and only the occasional check is required to keep yourself at optimum consistency.

Everyone I have told this method to, immediately either supports or condemns it as another way to cull "bad" bullets which is not what I was advocating at any time.
I have unsuccessfully tried to explain, that even though you can use this method to cull bullets, that is not it's real strength. The real strength of this method lies in finding where each mold likes to run, and more importantly, teaching yourself how to be consistent.
That's why I called the thread "Consistency applied" rather than "Cull for consistency" (which is in fact a contradictory concept).
The object here is to work yourself out of a job!

I hope that the readers can realize the purpose, and potential of this method as I have. It has taken me to levels of consistency that I never thought possible, and like I said in the OP, now I can take my pot off the shelf, add the alloy I prefer, heat everything up and just start casting good ones (like, REALLY good ones) right away.
I would like everyone to be able to enjoy casting like this.

[Jevyod]

All good info here Tim. One thing that I found out I was doing wrong was casting way to fast. I would only wait till the sprue froze, then cut and refill immediately. I just got back from casting 130 420 grainers for my 45-70. I slowed down my pour until I was doing one every 45 seconds. I had the melt at 750. With that temp, I am getting just slight frosting. I looked at them, and they look better than they usually do. I haven't taken the time yet to weigh, but plan to do that within the next few days. I actually enjoyed casting this way more than normal! I used to be afraid that any little pause would cool my mold too much.
So I am learning and trying to apply all I learn! I actually just ordered a hot plate for my mold so I can keep that more consistent. Next comes a pid (hopefully!!)