Cast target shooters : Weight sorting

[Wolfdog91]

Well my ADHD has me over here soring though a bunch of Boolits but I'm curious you guess who do all the high speed target shooting, the super tiny groups and all that. What are your weight sorting requirements? On the dot ? Half grain different ,one grain difference, tenth of a grain difference? I know all this probably isn't needed for what I'm doing but hay not like I sleep any way lol
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Also it's a good thing if your Boolits have gotten heavier since your first casting season right ? I mean I can't really see a difference other than my bases looking a bit more squared but I've jumped from mainly 56.0 grains after powder coating to manly 56.6 and above after PC.

[Bird]

From my experience, if I have a 0.5% spread from the lightest to the heaviest bullet it makes no difference at least for 100 yards rifle shooting....that's about as far as I can see a target these days. So for a 180 grain bullet, its good to go if they are 179.5 to 180.5 grains, but they usually come out with less weight spread than that.
I keep the first 15 or so bullets to one side after the mold is up to temperature, and compare them to the larger batch I have cast. I find there maybe the biggest difference in those first few I have cast.
I don't bother weighing each bullet for rifles, and it makes no difference at all for pistol at 25'.
There are more important factors with shooting cast in rifle, that is wind drift that is acting upon cast bullets at the lower velocities. The bullet is in the air longer than a higher velocity jacketed bullet, and the wind has longer to act upon upon it, which affects group size more so.

[Land Owner]

I am no "expert" and like you "feed the Jones" of weight sorting cases, boolits, and powder charge in the hope of identifying and one day shooting a "one hole group" (its the journey). This practice resolves the "time on my hands" as I line up cases from light to heavy weight and boolits from heavy to light weight trying to "normalize" shot to shot differences.

Does it make ANY difference? I THINK IT DOES, which is all that matters, as I become intrinsically confident in the ammunition I make, for the guns that I shoot, through the testing I perform.

[gunarea]

Hey Wolfdog
This falls into your particular preferences. Those who will tell you it makes no difference are not the ones on the podium at the end of the tournament. Close enough is for skill levels that are adequate. Winning a local match with Wal-Mart ammunition is not unheard of. Winning at state or national competitions is done with precision ammunition. From there it is a dictionary issue. Your quest is simple as the love for your hobby. My experience covers over fifty years of serious competition. Many conversations with peers and students of this endeavor. This chest pounding includes a handful of Florida state medals, more than a few are of gold. I can tell you from empirical knowledge, close enough does not win these contests. When taking the life of another creature, this same effort should be applied, out of respect. You are right about the mental condition of confidence making a difference. The delicate ego needs the out of questionable ammunition. When I miss, it is me! You are not wrong to pursue. Sometimes the pursuit is the pleasure. Keep it up, this is where improvement and innovation comes from.
Roy

[B R Shooter]

I concur with Roy. I've shot benchrest a long time, but cast BR only a couple years. In my view, every variable should be taken out. Shot to shot consistency wins. I prep brass as close to the same as I can, and maintain them. Weighed powder charges. You need a good gun platform too, but that's another subject. Then there are the boolits. There are some things you can't control. You'll never know if there is an inclusion inside the bullet. We shoot an alloy, how do we know every bullet has the exact blended mixture? Weighing, measuring, is what we can do. Getting the base and gas check as square as possible is another.

[high standard 40]

I agree with gunarea and b r shooter. I won a regional competition shooting cast bullets against other shooters using match grade jacketed bullets. That didn't happen for me by saying "ah, that's good enough" If for no other reason, sorting by weight can be a tool for achieving more consistent casting results. If you don't realize you have casting technique issues, you can't correct them.

[DonHowe]

Unless bullets I cast are for pistols or plinking (which I don't do much of) I sort by weight because it is one of the things I can control.
For several years I competed in schuetzen benchrest where bullets are fairly soft and plain based. The 200 yd score target has a 25 center ring 1.5" in diameter. Some shooters I have known held to the tradition of shooting bullets in the order they were cast with only visual inspection. sOME of these shooters have shot impressive targets even record targets. I believe the best of these shooters are such consistent casters that if their match bullets were weighed they would be found to be very consistent in weight. I like to think I am a proficient caster and sometimes am very consistent but weighing finds the odd bullet often enough to shake my confidence. So I will continue to weigh rifle bullets.

[dverna]

Just something to ponder...

Say your bullets average 55 gr. You do your weight sorting and put them in groups of
54.3-54.5
54.6-54.8
54.9-55.1
55.2-55.4
55.5-55.7

Will you expect the 54.3-54.5 bullets to groups as well as the 55.5-55.7? The tolerance is about the same as % of weight. (.37% vs .36%)

Now think about why one group is averaging a lower weight (over 2%) than another group...what would cause that?

It seems to me, that unless whatever is causing the weight difference is homogenous (density variation of alloy) or a void/inclusion that is centered on the axis of every bullet, the lighter bullets are suspect. You cannot stuff more alloy into a bullet to make it come out heavier...full is full. About the only way you can get heavier bullets during a casting session is to not completely close the mold.

I will be interested in seeing how your sorted bullets shoot.

BTW, in spite of what has been posted, cast bullets are never an advantage over jacketed bullets unless cost is the criteria. The vast majority of bullet casters cannot achieve the performance of $30/100 .30 cal hunting bullets...and none can out perform a match grade bullet. What a good shooter can do on a good day, is not the norm.

Do not drink the Kool-Aid. Hone your casting skills and set realistic goals. IMO, a 2500 fps .224 cast bullet load that shoots 2 MOA 10 shot groups EVERY time is a VERY impressive accomplishment. But that is easy with run of the mill jacketed bullets.

Good luck.

[JonB_in_Glencoe]

weighing boolits for shooting accuracy:
This is a activity that you have to define the parameters for yourself, from your personal experiences.

Most of us seasoned boolits casters don't weigh sort boolits. But weigh sorting is an excellent practice for a newbie boolit caster to judge how well you casting session was. A casting session where you were on top of your game with your rhythm and maintaining consistent mold temperature, should yield a batch of boolits that are less the 1% weight variance...and probably more like 0.1% weight variance.

[Thumbcocker]

Frank Marshall wrote articles about orienting the boolits in the chamber for best accuracy. I believe he weight sorted as well.

[JSnover]

Frank Marshall wrote articles about orienting the boolits in the chamber for best accuracy. I believe he weight sorted as well.
I don't know who wrote it, but I've also read of shooters orienting cases in the chamber.

[Larry Gibson]

Well my ADHD has me over here soring though a bunch of Boolits but I'm curious you guess who do all the high speed target shooting, the super tiny groups and all that. What are your weight sorting requirements? On the dot ? Half grain different ,one grain difference, tenth of a grain difference? I know all this probably isn't needed for what I'm doing but hay not like I sleep any way lol
279410279411

Also it's a good thing if your Boolits have gotten heavier since your first casting season right ? I mean I can't really see a difference other than my bases looking a bit more squared but I've jumped from mainly 56.0 grains after powder coating to manly 56.6 and above after PC.

What I'm about to say is not criticism but just the way it is. As mentioned many here, if not most, here do not weight sort their cast bullets because they think it doesn't do any good. Many here, if not most, have not the interest to do so because their equipment/style/method of shooting doesn't produce any beneficial results. Many here, if not most, while they cast good bullets do not cast excellent bullets where proper weight sorting is beneficial. Many here, if not most, who have tried weight sorting weight sort incorrectly based on incorrect information they've read or watched on U-Tube.

Perhaps this will answer your question;

Weight Sort 30 XCB Cast Bullets


"For your theory, that lighter bullets in a batch are less accurate than the heavier ones we must assume: 1. that light bullets are caused by voids, 2. that those voids are not too near the longitudinal axis and, 3. that they are large enough to be significant."

Ergo is the problem in this discussion. I do not subscribe to any of those 3 assumptions. In fact if you re-read my post with the graph I explain what I've found to be the real problem and it is not the suspected or assumed "voids" in the bullets. Yes, that's what we've all been told for probably a hundred years and it is what we've based our testing on.

Ten years ago I thought I was casting pretty good bullets, excellent in fact. However. the more I got into shooting cast bullets at HV I found while I was casting good, excellent bullets I too hit the accuracy wall that joeb is alluding to. I also found that when those cast bullets were pushed to really HV (2500 - 3000+ fps) they did not do as well as expected. Back then I was weight sorting as we've all been told to. If you line them out by weight you get the so called "bell curve". In proving insanity I, like you and everyone else, then did the same testing of each .1 gr testing over and over again expecting different results.....we all got the same results; accuracy was not really improved via that method no matter how many times we ran the test. You are asking me now to run the same test and think I will come up with different results? It wouldn't happen.

Let's assume we have a mould that will cast perfectly even bullets in all dimensions. Not an assumption but fact is that mould has a finite capacity for any alloy. Thus if we cast with a good alloy giving the best fillout then only those that weigh the heaviest will have filled the mould out completely. Any bullets with less weight are then not dimensionally the same. We may not be able to measure other than weighing that difference but the difference is there in lighter weight bullets none the less. Now that difference in weight (mass) is there but it is not predictable.....we don't know where in or on the bullet that difference in weight is missing from. The missing weight is what creates the imbalance. I suspect voids in the alloy are not the problem but rather other aspects are which I have previously discussed.
I recently cast 542 NOE 30 XCB bullets of #2 alloy. I have just completed weight sorting them. In the next post I will show the graphed results of the weight sort which should aptly demonstrate what I'm saying. Have to copy, download, etc. so it will be an hour or so.

Here is the results of the weight sort. 542 bullets were cast of Lyman #2 alloy and WQ'd. They were then aged about 12 days before I got around to weight sorting. Here is my set up for weight sorting. I visually inspect each bullet for any defect. If any is found that bullet is rejected to be melted and recast at a later casting session. Those that pass my anal visual inspection then have any remnant of the sprue cut off. That is done on the lead block with a sharp blade on the pocket knife. The bullet is then weighed on the Redding balance beam scale. While waiting for the beam to settle I then visually examine and sprue cut another bullet. With the magnifier in front of the scale I can readily and accurately see what the weighed bullets exact weight is. The bullet is then placed in a bin for that weight.

Of the 542 bullets weighed 22 were rejected for a visual defect or because they weighed less than 156.9 gr which means the weighed ones had passed the visual inspection but still weighed way lite. The remaining 520 XCBs were weight sorted into separate bins of .1 gr increment from 156.9 gr to 158.0 gr......a 1.1 gr spread.

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Here is the rough graph of the weight sort. As you can see there is no "bell curve". The curve rises from 156.9 gr slowly to 157.5 gr and then rises sharply. The "curve" then plateaus out at 157.7, 157.8 and 157.9 gr with 113, 124 and 110 bullets for each weight. The "curve" then falls sharply to just 9 bullets at 158.0 gr. Of those 9 bullets only 2 actually weighed 158.0 gr. The remaining 7 bullets weighed between 157.9 and 188.0 gr. There were no bullets heavier than 158.0 gr.

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The weight sorting is showing us the 113 bullets of 157.7 gr, the 124 bullets of 157.8 gr and the 119 bullets (I'll put the 158.0 gr bullets in with those) of 159.9 gr weight has the highest weight/mass of alloy in them. Since the curve dropped off suddenly we see those weight bullets are the most consistent and the best the mould will produce with that alloy. Those 356 weight selected bullets will be used for best accuracy.

The 157.6 gr bullets will be used as fouler/sighters as I expect they will give very good accuracy also given only a .2 gr +/- difference in weight.

Had we lumped all the visually selected bullets into one group 70% would have been with the excellent bullets, another 15% would have been with the fouler/sighter bullets and the remaining 15% would have been with bullets having a weight/mass difference of 1.1 gr. Now, had I done that I probably would have got nice 1 1/2 moa groups with 7 +/- shots going into moa or less and 2 -3 +/- shots going out of the group in the 1 1/2 moa +/-. How many of you shoot groups like that with bullets only visually sorted?
It is with such weight sorted selected bullets (the 157.7 to 157.9 gr bullets) that I am able to hold moa accuracy to 300 yards and beyond with a 2900+ fps velocity.

That is how I weight sort and why it makes a difference.

[Dimner]

I weight sort.

I use a franklin armory digital scale and it has about a 0.1-0.2 grain drift. More drift than I would like, but it allows me to weight sort decently.

Depending on the size of the bullet profile I am casting with, the overall spread of a casting session is anywhere from 0.6 to 1.0 grains. Low quantity outliers are culled, and then I end up having maybe 2 or 3 groups of like weighted bullets all within 0.2-0.3 grains of each other. After that, when I am cooking up loads, I grab bullets in the same weight group.

[Larry Gibson]

Wolfdog91

In answer to a similar question as yours;

"Larry,

Those are some nice groups. With regard to consistent boolit weight, what do you consider consistent? Plus or minus X.X grains?
It depends on the weight of the cast bullet to begin with. Most weight sort thinking those bullets that weigh the same or with a +/- will shoot the best. I've learned that while that method of selection will give better accuracy it will not give "the best". As I weigh each bullet I visually inspect the bullets first. Any visual defect, no matter how small, is cause for rejection. I then weight sort to eliminate those very light bullets that passed the visual inspection but obviously have a void inside. I then put the bullets into small plastic bowls of .1 gr increments."

I'll explain with 7mm to 32 caliber bullets of 150 to 220 gr as an example. Many who weight sort will kind of "graph" the bullets out by lining them up in tenth grain increments that are consecutively numbered and straight across the bottom. What you end up with is a "bell curve" shape of bullets. The curve starts out curving up, peaks out and then curves back down almost the same as it went up. The majority of the bullets in the curve will have a 1 to 1.5 grain difference in weight. There will be some that are much lighter and a few heavier. That is what you get with "good" cast bullets.

Using a quality alloy that will cast excellent bullets is also paramount. This is why straight linotype and #2 alloy are most often used. They give excellent and uniform fill out, consistency of weight with fewer defects. Some batches of COWWs will also if the antimony and tin percentages are sufficient and balanced. Alloys in these smaller caliber bullets that give a lot of shrinkage will never cast "excellent" bullets no matter how good they look. The reason is we cannot control the shrinkage and where it occurs on each bullet. Slight shrinkages that are in different places on the bullet are undetectable by visual or even precise measurement and they mean a slightly unbalanced bullet. Might not seem like much but at higher RPM and/or at longer ranges of 200 yards and beyond it is readily detectable on target by enlarged groups and poorer accuracy. Complete fill out in the mould and minimal shrinkage is needed for a quality cast bullet that will give the best accuracy.

Weight sorting the visual inspection passed bullets with "excellent cast" bullets gives a weight sorted curve that rises sharply and then levels off with several weights (three or four of .1 grain increment) having about the same number of bullets. The curve then falls sharply to just a few heavier bullets. There is no downward "curve".

When I got the 4 cavity NOE 30 XCB mould I ran this test with Lyman #2 alloy;

I cast 531 bullets

1.9% were rejected for visual defects

8.6% weighed less than 157.7 gr (some as much as 2 gr less that obviously had internal voids I could not detect through visual inspection)

3% weighed 157.8 gr

4.5% weighed 157.9 gr

5.9% weighed 158 gr

18.7% weighed 158.1 gr

19.3% weighed 158.2 gr

21.6% weighed 158.3 gr

14.7% weighed 158.4 gr

1.8% weighed 158.5 gr.

I then loaded 10 shots of each increment (157.8 gr to 158.5 gr) to test at 300 yards.

Test rifle was my 30x60 XCB. The NOE bullets weight 164 gr +/- when fully dressed and were loaded over 53 gr of AA4350 which runs 2900+ fps out of that rifle. The incremental test loads were fired consecutive by weight with the barrel cooled, cleaned and then fouled with 2 fouling shots prior to the next increment test. The results were then graphed out for a simple visual comparison.

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We see the lighter weight 157.8 and 157.9 gr bullets were not as accurate. The lighter weight bullets giving indication to probable incomplete and inconsistent fill out and/or shrinkage or that they have small void(s) in them. The "heavy" end of the bullets (158.0 through 158.5 gr) gave consistent accuracy (precision) at very close to moa at 300 yards. I have run this test several times and with cast bullets in the 150 - 180 gr weight range I select the heavy end of the weight sorted bullets +/- .2 to .25 gr. With this weight range I use the 157.8 and 157.9 gr bullets for foulers and the 158.0158.1 bullets for sighters. The 158.2 through 158.5 are then used in matches and other tests where precision is measured. For the best accuracy at this level of high velocity the top half (158.3 to 158.5 gr) of those selected bullets almost always give the best results, particularly at 200 and 300 yards.

With other weight ranges I like wise run a similar weight sort test and now select the heavy end of the match selected weight sorted bullets for accuracy/precision use.

[Larry Gibson]

Wolfdog91

The pay off, especially at HV and longer range,;

The 30 XCB, 308W, 500 Yards, 10 & 12” twists

On another forum I was asked how well I could shoot the 30 XCB at 500 yards, particularly at a velocity of 2250 fps +/- having pushed the RPM Threshold up from 1940 fps. It had been several years since I did any long range shooting with the XCB in a 10” twist and then the longest range was 300 yards. Most of my LR shooting with the XCB in the 14” twist .308W Palma rifle and the 16” twist 30x60 XCB “DAWN” have been also limited to 300 yards. I did informally shoot out to 400 yards but nothing on record as such. Time to do some 500 yard shooting on target.

The cold weather front shifted a day earlier than expected so it cooperated this morning, February 26, 2018, at least for the 500 yard shooting. By the time I got to 600 yards the wind was switching back and forth from 5 o'clock to 9 o'clock and pushing 12 to 14 mph so I didn't attempt shooting there at 600 yards with the 30x60 XCB in my rifle “DAWN”. I did however get fairly decent shooting conditions at 500 yards and got decent groups with my 10" and 14" twist .308Ws at 500 yards this morning.

This morning dawned at 39 degrees with a 2 mph wind coming out of the SW. I was at my long range shooting local north of LHC about 30 minutes later. I set up the target and my wind flag and then went to the 500 yard firing point and set up a portable BR. It's not the sturdiest bench in the world but it will do. From the firing point the wind was running 3 - 6 mph out of 7 to 8:30. By the time I was ready to shoot the sun was up and the temp was 45 degrees and the humidity 28%.

The first rifle shot was my M1909 Argentine with a 24" A&B barrel with a 10" twist. It's in a wood sporter stock. The scope is a 10X Weaver MicroTrac with friction adjustments. The load is the 30 XCB cast of #2 alloy and WQ'd, weight sorted as previously mentioned. The XCB was loaded in LC72 Match cases (match prepped of course) with WLR primers. The load I used, 44 gr RL22, is the same load that had proven extremely uniform and accurate at 2267 fps (163,224 RPM) in the thread I posted and suggested you read about how the RPM Threshold can be pushed up. For calculating sight adjustment for elevation and the wind I used the “Applied Ballistics” program I got with Bryan Litz’s very fine book on long range ballistics. That was really beneficial because it got me pretty close elevation wise. Also I had calculated the wind correction in moa and that was very helpful. Before the shooting at 500 yards was done the wind was steady at 4 – 8 mps coming out of 8 o’clock. That required 7 +/- moa (30 to 50” at 500 yards) adjustment for the wind with the 2267 fps load out of the 10” twist rifle. I had put up a good wind flag which was very helpful as I tried to shoot in the same wind condition.

I had set a rock about 6 – 8” I had painted black off to the side of the target to use as a “sighter”. With the .308W rifle with 10” twist it took a bit to get on target at 500 yards with that older Weaver scope is friction, not click adjustable and the turret marks were not moa. I did manage to get the 10 test shots on target before I ran out of ammo.....barely. The group was not centered up on the target. Here's the rifle on the bench (sorry, no slick video as I'm so like last century....just some pictures and on target results)......if you save that picture to a file you can enlarge it and see the target and range flag on the face of that far ridge where the barrel is pointed.

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Here's the target. Note two of the shots creased the edge of the target frame so I counted them in the group. Here's the target measurement. It is an 11 3/4" ten consecutive shot group at 500 yards. I covered the bottom bullet hole up with the tape taking the picture. However you can see it in the other photo. The HV load (for a 10" twist) is holding very close to 2 moa (actually 2.35 moa) at 500 yards. Obviously the RPM Threshold has been pushed up but yet is still manageable. In the 2nd picture you can see the range flag hanging limp. Seemed like every time I went to check/change the target the wind died. Then as soon as I got back to the bench it started blowing again…..go figure……

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I then switched rifles to see what controlling the RPM by using a slower twist and boosting the velocity can do for us. The next test was with my Palma rifle with a 27.4" light Palma S&L 14" twist barrel in 308W on a M98 byf action. The load is the standard 2600 fps load I worked up several years ago. It is 47 gr AA4350 in Winchester cases with WLR primers. Again the NOE 30 XCB bullet was cast of #2 alloy and WQ'd. The Lube was 2500+ and GCs are Hornady's. With the 14" twist 2600 fps is 133,714 RPM, considerably less than with the 10" twist at 335 fps less velocity. The Palma load is well under it’s RPM threshold.

Here's the 500 yard 10 shot group from the Palma rifle at 2600 fps. With the precise elevation/windage adjustments of the Weaver T-16 on the rifle it didn't take long to get centered on target. Still I was using 4 +/- moa of wind adjustment. Here is the group measurement. The 10 shot group at 500 yards is 7 3/4" which is 1.45 moa.

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So, there are the 500 yard 30 XCB test results that was asked for. This was a lot of fun for sure and I’m watching the weather forecast for the next low wind day. Then I’ll be off again with DAWN to shoot at 600 yards……..

[Larry Gibson]

And at 600 yards;

http://castboolits.gunloads.com/showthread.php?356607-NOE-30-XCB-30x60-XCB-600-yards

[B R Shooter]

If accuracy is what matters, it don't come easy. But it's possible. Accuracy means a lot of different things to many people.

[dtknowles]

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We see the lighter weight 157.8 and 157.9 gr bullets were not as accurate. The lighter weight bullets giving indication to probable incomplete and inconsistent fill out and/or shrinkage or that they have small void(s) in them. The "heavy" end of the bullets (158.0 through 158.5 gr) gave consistent accuracy (precision) at very close to moa at 300 yards. I have run this test several times and with cast bullets in the 150 - 180 gr weight range I select the heavy end of the weight sorted bullets +/- .2 to .25 gr. With this weight range I use the 157.8 and 157.9 gr bullets for foulers and the 158.0158.1 bullets for sighters. The 158.2 through 158.5 are then used in matches and other tests where precision is measured. For the best accuracy at this level of high velocity the top half (158.3 to 158.5 gr) of those selected bullets almost always give the best results, particularly at 200 and 300 yards.

With other weight ranges I like wise run a similar weight sort test and now select the heavy end of the match selected weight sorted bullets for accuracy/precision use.

Wolfdog91
You see Larry's lighter bullets were not as accurate but that difference was about .3 MOA. If you have a gun that shoots groups that are around 1 MOA then .3 MOA might mean a lot to you. Not many people have guns that will shoot cast bullets to 1 MOA, culling the light bullets might help but it might not even be noticeable in your gun.

About your bullets gaining weight from aging. That does not happen. I think you have a scale calibration/warm up issue.

Tim

[Wolfdog91]

O boy y'all are gonna have to give me a second here , really really love all the info but I'm not the brightest bulb in the chandelier so it's gonna take me a little bit to comprehend all this lol. :shock:
Honestly was just expecting a few yes /no and I sort mine by these parameters lol. Lemme try and process all this

[Wolfdog91]

Wolfdog91
You see Larry's lighter bullets were not as accurate but that difference was about .3 MOA. If you have a gun that shoots groups that are around 1 MOA then .3 MOA might mean a lot to you. Not many people have guns that will shoot cast bullets to 1 MOA, culling the light bullets might help but it might not even be noticeable in your gun.

About your bullets gaining weight from aging. That does not happen. I think you have a scale calibration/warm up issue.

Tim

Well I wasn't referring to them gaining weight from aging I was saying the oner I weighted after my first casting session where lighter than these which are a new batch from a different session

[waco]

In this video I am shooting my Rem 700 .308 with the NOE 30CXB bullet. I sorted all of them to within .3gr of each other. I am running them at 2600fps using lube and a gas check. The target is a 10" steel plate at 500 yards.
https://www.youtube.com/watch?v=l9VDouNYi7A

[Goofy]

Weight sort in .1 gr increments and put them away for future use in ascending order. Seems to work for me.

https://i.imgur.com/0LR49yA.jpg

[charlie b]

Yep, I am another weight sorter. I did the same kind of experiments Larry did trying to figure things out and found the same results with regard to bullet weight. The group size tests and weight grouping charts were almost identical in shape.

One other thing I did as a further test was to vary casting temperature and found that would change bullet weight, sometimes by several grains. So, at least in my case, I believer the variance is mainly due to slight temperature changes during casting (lead and mold).

I also think that the 'very light' bullets are light due to a void. My only evidence of this is the severe change in group size when I shoot the bullets at the lighter end of the scale. Most of my shooting has shown that the threshold is somewhere around 2gns from the 'sweet spot'. If there was no void then they should group just as well as the heavier bullets.

And, yes, the pursuit of the sub-MOA cast bullet load can be an exercise in frustration :)

[RonIa]

As a bench rest shooter using my hand swaged jacketed bullets I find this thread very interesting I'm not sure if the two are all the same but how long the jacket is the twist rate and how fast you push your bullet makes all the difference in the world finding the perfect node by two different ways speed ( powder at the right burn rate ) and seating depth a bullet is like a tire on your car if it's out of balance you wont tell at low speed but run that at a higher speed and it will shake it's called the gyroscopic stabilizing units ( fancy word for how fast it will go before it's out of balance ) over time we have found that a 1in 17 or 1in 18 twist barrel using a 1 inch or .925 jacketed bullet in a 30 BR case is the cats meow just a few things to add to the quest of accuracy some of this may or may not help I hope it does
Ron

[jim147]

Weight sort in .1 gr increments and put them away for future use in ascending order. Seems to work for me.

https://i.imgur.com/0LR49yA.jpg

That a great example of shoot for group. When working up a load you must aim at the same point and ignore if they miss the 10 ring.

[dtknowles]

Well I wasn't referring to them gaining weight from aging I was saying the oner I weighted after my first casting session where lighter than these which are a new batch from a different session

I see that now that I reread you OP. Yes, it is better that you are getting more fillout if that is what is making your bullets heavier.

Tim

[Wolfdog91]

What I'm about to say is not criticism but just the way it is. As mentioned many here, if not most, here do not weight sort their cast bullets because they think it doesn't do any good. Many here, if not most, have not the interest to do so because their equipment/style/method of shooting doesn't produce any beneficial results. Many here, if not most, while they cast good bullets do not cast excellent bullets where proper weight sorting is beneficial. Many here, if not most, who have tried weight sorting weight sort incorrectly based on incorrect information they've read or watched on U-Tube.

Perhaps this will answer your question;

Weight Sort 30 XCB Cast Bullets


"For your theory, that lighter bullets in a batch are less accurate than the heavier ones we must assume: 1. that light bullets are caused by voids, 2. that those voids are not too near the longitudinal axis and, 3. that they are large enough to be significant."

Ergo is the problem in this discussion. I do not subscribe to any of those 3 assumptions. In fact if you re-read my post with the graph I explain what I've found to be the real problem and it is not the suspected or assumed "voids" in the bullets. Yes, that's what we've all been told for probably a hundred years and it is what we've based our testing on.

Ten years ago I thought I was casting pretty good bullets, excellent in fact. However. the more I got into shooting cast bullets at HV I found while I was casting good, excellent bullets I too hit the accuracy wall that joeb is alluding to. I also found that when those cast bullets were pushed to really HV (2500 - 3000+ fps) they did not do as well as expected. Back then I was weight sorting as we've all been told to. If you line them out by weight you get the so called "bell curve". In proving insanity I, like you and everyone else, then did the same testing of each .1 gr testing over and over again expecting different results.....we all got the same results; accuracy was not really improved via that method no matter how many times we ran the test. You are asking me now to run the same test and think I will come up with different results? It wouldn't happen.

Let's assume we have a mould that will cast perfectly even bullets in all dimensions. Not an assumption but fact is that mould has a finite capacity for any alloy. Thus if we cast with a good alloy giving the best fillout then only those that weigh the heaviest will have filled the mould out completely. Any bullets with less weight are then not dimensionally the same. We may not be able to measure other than weighing that difference but the difference is there in lighter weight bullets none the less. Now that difference in weight (mass) is there but it is not predictable.....we don't know where in or on the bullet that difference in weight is missing from. The missing weight is what creates the imbalance. I suspect voids in the alloy are not the problem but rather other aspects are which I have previously discussed.
I recently cast 542 NOE 30 XCB bullets of #2 alloy. I have just completed weight sorting them. In the next post I will show the graphed results of the weight sort which should aptly demonstrate what I'm saying. Have to copy, download, etc. so it will be an hour or so.

Here is the results of the weight sort. 542 bullets were cast of Lyman #2 alloy and WQ'd. They were then aged about 12 days before I got around to weight sorting. Here is my set up for weight sorting. I visually inspect each bullet for any defect. If any is found that bullet is rejected to be melted and recast at a later casting session. Those that pass my anal visual inspection then have any remnant of the sprue cut off. That is done on the lead block with a sharp blade on the pocket knife. The bullet is then weighed on the Redding balance beam scale. While waiting for the beam to settle I then visually examine and sprue cut another bullet. With the magnifier in front of the scale I can readily and accurately see what the weighed bullets exact weight is. The bullet is then placed in a bin for that weight.

Of the 542 bullets weighed 22 were rejected for a visual defect or because they weighed less than 156.9 gr which means the weighed ones had passed the visual inspection but still weighed way lite. The remaining 520 XCBs were weight sorted into separate bins of .1 gr increment from 156.9 gr to 158.0 gr......a 1.1 gr spread.

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Here is the rough graph of the weight sort. As you can see there is no "bell curve". The curve rises from 156.9 gr slowly to 157.5 gr and then rises sharply. The "curve" then plateaus out at 157.7, 157.8 and 157.9 gr with 113, 124 and 110 bullets for each weight. The "curve" then falls sharply to just 9 bullets at 158.0 gr. Of those 9 bullets only 2 actually weighed 158.0 gr. The remaining 7 bullets weighed between 157.9 and 188.0 gr. There were no bullets heavier than 158.0 gr.

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The weight sorting is showing us the 113 bullets of 157.7 gr, the 124 bullets of 157.8 gr and the 119 bullets (I'll put the 158.0 gr bullets in with those) of 159.9 gr weight has the highest weight/mass of alloy in them. Since the curve dropped off suddenly we see those weight bullets are the most consistent and the best the mould will produce with that alloy. Those 356 weight selected bullets will be used for best accuracy.

The 157.6 gr bullets will be used as fouler/sighters as I expect they will give very good accuracy also given only a .2 gr +/- difference in weight.

Had we lumped all the visually selected bullets into one group 70% would have been with the excellent bullets, another 15% would have been with the fouler/sighter bullets and the remaining 15% would have been with bullets having a weight/mass difference of 1.1 gr. Now, had I done that I probably would have got nice 1 1/2 moa groups with 7 +/- shots going into moa or less and 2 -3 +/- shots going out of the group in the 1 1/2 moa +/-. How many of you shoot groups like that with bullets only visually sorted?
It is with such weight sorted selected bullets (the 157.7 to 157.9 gr bullets) that I am able to hold moa accuracy to 300 yards and beyond with a 2900+ fps velocity.

That is how I weight sort and why it makes a difference.

Ok so if I'm understanding all this correctly , the weight sorting is basically a must if your running cast at higher velocities and trying to get above average accuracy. Interesting, and since I've been told multiple time these smaller bullets amplify all common casting problems , im definitely going to have to weight sort , awesome . BTW forgive me if im missing over the finer points here, again not the educated person in alot of these thing but im trying lol

[Larry Gibson]

Wolfdog91

Obviously you are new to this game. We all have to learn. many of us did not have video's or the internet forums for mentorship in the learning process. We learned by reading and by trial and error. There are many myths, old wives tales and just plain BS in this cast bullet endeavor just like many other endeavors. You'll have to find, usually the hard way, what really works with what you want to do.

The higher the velocity, given a specific barrel twist, the higher the RPM of the bullet will be. It is the centrifugal force created by the RPM that that acts, adversely to accuracy, on the imbalances in the bullet. The better balanced the bullet is the more accurate it will be. Hornady manuals have an excellent explanation of how imbalances in bullets, even quality jacketed bullets, cause dispersion of the bullet (group size) btw. Proper weight sorting of well cast bullets sorts out the imbalanced bullets.

[Krag 1901]

Gosh you guys get down the the nitty gritty. I've weight sorted and found a wide range in my 200 gr .30s. I'm putting it up to differences in the alloy due to my not mixing the pot well enough or temp variations. I just got a new 314299 mold and will be casting some boolets soon. I'll try to do better with temp stability and mold timing to keep the new steel mold hot. I generally cast with Lee Alum molds so it's going to take some time to get used to the Lyman mold.

I've only got one bragging group with my Krag, Lee 312-16-2Rs with 19 gr 2400 gave me 10 out of 15 shots in less than an inch at 50 yard the other five in about 2" and I think it was my boolets and my shooting that caused the outliers.Aperture sights. I didn't think that too bad for an old duffer.:bigsmyl2:

I'll be weight sorting the 299s to see how well I'm running the pot and mold temp. but will shoot then all just to see how the weight variations shoot.

[Land Owner]

For a small boolit, 50 gr. (as is the 22 Bator), weight sorting by one tenth of a grain (0.10 gr.) is one five hundredth (1/500) of the boolit's total theoretical weight. For (say) a 45 ACP boolit of 200 gr., 0.10 gr. is 4X smaller (1/2000) and has significantly less impact on rotation and/or accuracy. The "impact" of weight discrepancy is (imo) not proportional, but exponential, and magnified in light boolits. I have no data to back that up...just an opinion.

[oley55]

Pics of my weight sorting session from March 2016. The effort demonstrated there can be significant outlier weights in a batch, but also crystalized my OCD diagnoses. Weighing bullets on an old Redding scale with a weak dampening magnet conjures up a whole new meaning for the word 'tedious'. :veryconfu

[Krag 1901]

Pics of my weight sorting session from March 2014. The effort demonstrated there can be significant outlier weights in a batch, but also crystalized my OCD diagnoses. Weighing bullets on an old Redding scale with a weak dampening magnet conjures up a whole new meaning for the word 'tedious'. :veryconfu

You can get a digital scale pretty cheap that is +/-0.1 gr on Amazon. I bought two just in case I drop an anvil on one! Makes things a lot faster then you can check it against your balance scale.

[B R Shooter]

I weigh mine on the chargemaster scale, that reads to one tenth of a grain. Close enough.