Weigh check and sort?

Anyone else doing this with your cast Boolits? I know I am still new to this and some of this is being done just out of curiosity. One observation is that I'm not sure if it is the quality of the mold or if I am just improving technic! I have been weigh checking all along and sorting into groups for loading purposes. As I am progressing my weights are becoming much more consistent.

This last batch that I just cast yesterday are from a Lyman single cavity 452374 225gr RN. Ended up with 103 pcs. I cast some of these previously but I had the wrong handles and the blocks were not closing properly and they were all oversize and way over weight. I received the proper handles and WoW what a difference.

With this batch I found the median weight with this alloy for this mold was dropping at 228gr which I thought was very good. So as I was sorting these I set my parameters to +/- 0.3gr of the 228gr and ended with 70within this range and 10 pcs under the -3gr and 23 pcs over the +.3gr.. I didn't weigh for total variance but I believe it is less than 1.0gr +/-.

So again this is telling me that either I am getting better and more consistent or the iron mold is more consistent than the Aluminum. I'm hoping it's the case that I'm improving.

I don't know how long it takes for the different weight/densitys of the alloys to move around and stratify,
but stirring fairly often seems to help mine be more consistant .

I don't weigh & sort them for handgun stuff, but I still stir fairly often.

If I'm doing rifle ammo, I'm more careful & all.
And will sometimes sort a handful by weight to be as good as I can get them.

A older Lyman book had a 3-4 page article about that, and it was pretty informative.

Winger Ed, that's something to think about. I also have a Lee 452-200gr RNFP mold that I have cast before also so now I may just have to cast up another 100 of so and compare the results.

I have also changed from Ladle pour to bottom pour so I don't know how much of an effect that has had.

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Originally Posted by kmw1954

Anyone else doing this with your cast Boolits? I know I am still new to this and some of this is being done just out of curiosity. One observation is that I'm not sure if it is the quality of the mold or if I am just improving technic! I have been weigh checking all along and sorting into groups for loading purposes. As I am progressing my weights are becoming much more consistent.

This last batch that I just cast yesterday are from a Lyman single cavity 452374 225gr RN. Ended up with 103 pcs. I cast some of these previously but I had the wrong handles and the blocks were not closing properly and they were all oversize and way over weight. I received the proper handles and WoW what a difference.

With this batch I found the median weight with this alloy for this mold was dropping at 228gr which I thought was very good. So as I was sorting these I set my parameters to +/- 0.3gr of the 228gr and ended with 70within this range and 10 pcs under the -3gr and 23 pcs over the +.3gr.. I didn't weigh for total variance but I believe it is less than 1.0gr +/-.

So again this is telling me that either I am getting better and more consistent or the iron mold is more consistent than the Aluminum. I'm hoping it's the case that I'm improving.

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I cast till I can cast no more. Then I pick twenty random bullets and weight them. Usually they are within .2 grains of each other and that is plenty fine with handgun bullets. Now that I cast my own bullets for my 7.62X39 I weight each bullet, and I usually only cast 200 at a time of those since I only shoot feral hogs with those, but they must be within .1 grains. This gets me 1 to 1.5 inch groups at 100 yards at about 1900 FPS.

ACC

I don't remember the last time I weighed a bullet intended to be fired from a handgun, except to see how heavy a bullet was from a new mold. I couldn't possibly care less about weight-sorting handgun bullets.

I might sort rifle bullets intended to be fired beyond 100 yards.

I don't usually weigh cast bullets but a few experiments that I have done the bullets were within .3 grain of +or- .015. Thats in the ball park of your better jacketed bullets.

I’ve weighed a bullets from a couple batches to see what kind of variations I was getting. After doing it a couple of times I determined it wasn’t really worth it. Any outliers were due to small voids in the base of the bullet that can be identified by a quick visual inspection.

Agreed that I don't believe there would be any great advantage by doing this though as I stated in my 1st post that it is more out of curiosity and a way to judge my own consistency with what I'm doing. But as long as I'm doing it I might as well sort them. I will admit that my degree of variance has decreased since I started last summer.

to get all the boolits closer to the same weight and make sure the first cavity you cast has s filled out the base, prime the spout before the cavity on each pour

My action pistol sport requires meeting a power factor that is calculated using boolit weight and velocity, with each competitor's ammunition checked by actually pulling apart competitors' rounds and weighing the bullet, while shooting other rounds over a chronograph. So I need to know that all my loaded ammo has boolits of appropriate weight.

I don't weigh all of them, though. I need too many to weigh them individually. Instead, I go for casting consistency, which ends up getting me bullets within a very acceptable and predictable weight range.

By using the same alloy at the same PID controlled temp, in the same molds using the same casting techniques, I get pretty much all the same boolits each session, that I know will be in the weight range I need. They should hopefully also be more consistent in other ways.

But I have read, however, that weighing boolits is a good way of developing that consistency of technique.

The way I understand it, you weigh every boolit in a representative sample taken from a batch cast together, putting all of the different weights in separate lines that represent progressively greater weights. Starting all the lines on the edge of a piece of paper, you end up with a bell type curve, with perhaps the majority of boolits in lines more or less in the middle, and a few boolits of various higher or lower weights in shorter lines on either side. It's those side lines that represent the outliers in weight, and eliminating those lines by having more boolits in fewer lines in the peak of the curve is the goal.

Consistency in conditions, materials and technique influence the consistency of the final product. Besides the things mentioned in the third paragraph, ambient temp, wind conditions, mold temp and head pressure in a bottom pour pot were things I've read can be tweaked to get a more uniform batch of boolits, which can show up as more boolits in those center lines of the weight curve and hopefully few to none out on either side (a tall, narrow bell curve).

Yes, inspecting and weighing casts can get a good batch of uniform boolits by culling out the undesirables, but, at least for me, improving my technique is part of the fun and satisfaction of casting. Ymmv. ;^]

The boolits I use in competition, mostly at the Military Bolt-gun match at the local club, I weight-sort to .5gr groups.

I also weight-sort the brass into 1gr groups.

The off-weights I use for fouling or warm-up strings.

Yes, weight sort all my rifle bullets. I would weigh a few pistol bullets just to see what weight that mold throws, then never weight another one. Even 5gn differences in a pistol bullet do not affect the POI enough for me to see at 25yd.

My rifle bullets are in the 200gn range and are usually within 1gn of the target weight. Std Dev is usually in the 0.2gn range. I weight sort and will keep batches within .3gn. That has been good enough for sub MOA shooting.

My consistency when casting is not that great. I end up with a lot of flawed bullets when casting, approx 25%, mainly cause I only cast about 50 at a time before I have to give my hands a rest. Then, even with a hot plate, it takes a few rounds to get the temp of the mold right again. The nice thing is I have all the time I need to make bullets, so taking longer to get good bullets is not an issue.

Currently I only cast 45 Colt pistol bullets but these bullets get shot through both rifle and pistol barrels.
I weigh every bullet and place it on a like labeled post-it Note. After all the bullets are weighed they are packed in 50 count lots. Normally all the bullets in the 50 count lot will weight within 0.2 grains.
My entire batch of cast bullets may vary by several grains but each lot of 50 will be within 0.2 grains.
When I miss the target I can't blame my ammo only my shooting.

If I was a better shot, it might be worthwhile to weigh my boolits, but since I am not, I don't.

We all have some facet of this hobby that we get anal about. I have never made a habit of weighing boolits. Even when I was shooting IHMSA matches it just seemed irrelevant. I shot 429421 at 50-100-150 and 265gr Hornady condom bullets at 200 and never saw enough difference in dispersion between boolits & bullets to be concerned with.

My anal detail is case length. 38sp.-357-41M & 44sp I found a length that virtually all of them would clean up at for each caliber. When I bring in new brass they get trimmed for the first loading. I just like having uniform flare and crimp.

Weighing pistol bullets is a waste of time unless you do a lot of long range shooting.

Here is my data:
.45 200 gr SWC - first run - ES 1.7 gr SD .49 gr
.45 200 gr SWC - second run - ES 1.7 gr SD .53 gr
9mm 122 gr TC - ES 2.2 gr SD .49 gr
.38 130 gr RNFP - ES 3.3 gr SD .89 gr

BTW, those .38 bullets shot put 10 shots into just over 1.5 " at 25 yards out of a Marlin 1894. Good enough for me.

Thank you everyone for your responses, very enlightening.

I doubt I will make a consistent practice of this but again being new to this, about 6-7 months, I feel it has been useful to me to judge how my casting is progressing. I do feel it is progressing. I have done a few batches as kevin c describes and finding the "curve". This time I just found the median weight which was 228gr and then sorted into three groups, 228+/- .3gr and then one group above that and one group below that.

This mold is supposed to drop 225gr. Boolits so I was very happy to see them at just 228gr.. My first castings were done with a Lee 356-102 RN mold and those ended up dropping at 105/106gr with straight COWW alloy. I thought that was a bit excessive for that small bullet. Then the next was a Lee 452-200 SWC that dropped at 207gr with the same ally as the 356-102. Lastly was a Lee 452-200 RNFP cast with range scrap and it dropped really heavy at almost 210gr.

So once again part of this weighing was to see the difference in weight with the different alloys. These that I just cast were cast with the range scrap plus the 10% monotype added and again I ended with 228gr weight. So the monotype had a weight reduction effect. Next I am going to cast some of the 200gr mold again with this mixed alloy and compare the weight with the straight range scrap.

I believe as one gains more experience, consistent bullet weights will come with consistent methods. As your tempo, style, temperatures and alloy become more consistent, your bullets will become more consistent. I think any decent mold will not affect the consistencies of the bullets as the above factors...

You seem to be becoming a more consistent caster from casting and checking your progress so it's a win / win .

Do something long enough .... you get good at it !
After 50 years of casting a visual inspection is all I need , perfectly filled out corners , perfectly filled out base , no flaws ...it doesn't need to be weighed ...you can tell when they "look" right .

The secrete is to simply be totally consistent in your casting ....sounds so easy but it does require some practice .
Hang in there , practice consistency and soon you won't need to weigh them.
Gary

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Originally Posted by kmw1954

So the monotype had a weight reduction effect. Next I am going to cast some of the 200gr mold again with this mixed alloy and compare the weight with the straight range scrap.

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My understanding is that, since all the alloying metals we add to lead are less dense, the resulting alloy will cast a lighter boolit compared to pure lead.

There may be formulas that will predict the density of an alloy with more or less tin or antimony, or with mixed alloys of unknown content but known density, but, like you, I just do the empirical thing by taking notes on what weight I get with a given alloy and mold. Since I make up large batches of casting alloy from metals of known content, I'm pretty sure I can get consistent casting results.

I've made a very major effort to remove my OCD from the reloading process wherever necessary. There's a time and place, but unless you're shooting Bullseye matches, pistol bullets is not it. The human element brings way more error to the party than you'll ever see from a half-percent change in bullet weight. Save that focus for the long-range buffalo rifles.

Once you've weighed a few to see what your alloy yields, your better Q.C. method will be to check visually for good fillout, sharp bases, and flush cuts on the sprues. If your technique is good, and your multi-cavity mold uniform across all the holes, consistent weight will take care of itself.

Bigslug I wholly agree. This isn't the worst of the OCD. This is more of a curiosity than anything. My real OCD comes in the form of weigh checking powder drops. Even though I use a powder measure with powders that are very consistent I still weigh to often. Like every tenth one. Then like you say I also know that I cannot differentiate between a load that may be .3grains off either way when they are all strung together.