Why You Should Weigh Your Bullets

[Castaway]

This is why you should weigh your bullets. Four and one. One day, I’ll get five

[sharps4590]

Shoot a fouling shot off to the side, then shoot for group....if the first shot was from a cold, clean barrel.

[Castaway]

Flyer was 4th shot

[indian joe]

This is why you should weigh your bullets. Four and one. One day, I’ll get five

I know ya didnt flinch but that is exactly where mine go when I do - high and wide at 11oclock - can show a bunch of competition targets with one of the ten out there. I'm workin on it but aint happened yet!................

[Castaway]

Possible flinch, but unlikely, was sand bagged in and called a good shot

[sharps4590]

Flyer was 4th shot

Ha! I would not have suspected that.

[Harter66]

I thought it was so you'd know your 27-130 weighed 141 gr dressed so you didn't drop primers when groups were closing and still 1 gr under max to keep closing them ........ New rifle needed to be proofed anyway .

I'll enter a guess of lube purge . Your running just a little too much or something is just too much of a good thing in your lube . Your pushing the excess out or riding over it . Either way the excess is pushed out or causes an uncontrolled base defect . Viola' bullet out . It's impressive that you have it down to the same round every time .

[fastdadio]

This is why you should weigh your bullets. Four and one. One day, I’ll get five

Izzat powder burns I see on that target?

[Castaway]

fastdadio, any powder would have had to travel 100 yards

[KenH]

Powder burns on target? That's funny

Is it always the 4th shot that gives the flyer? If so, that's also interesting. BUT - my congrats on good shooting with a good "dialed in" rifle.

[Castaway]

On a good day, I can get 5 at 1.75”, plus or minus w/o the flyer. I’m convinced the anomaly was due to a bad bullet. The above is the best I’ve ever done, by far. Flyers for me can happen anywhere in the string, there’s no pattern.

[popper]

Interesting you think weighing bullets would catch bad ones. So a single grain of alloy is what volume? Say you have an air bubble and it gets compressed when firing. How much does it really distort the bullet? It will NOT throw that flyer! I shoot RNFP cast from an AR10 308w 2400 fast loads, some with nose deformation and don't get that large a dispersion. Long time ago I nicked the base of some 40sw, ~1k fps and saw a nice 4" circle of holes on the target. You either pulled it or had a damaged bullet, not a 1gr difference due to a void. Yes excessive lube can cause it.

[Castaway]

Bad base makes sense but these were checked. Could a badly applied check or the check flying off cause it? The lube problem is new thing for me. I wipe a wet and dry patch between shots. Could a void in the grease groove cause a 4” flyer?

[tmanbuckhunter]

I was getting the occassional flyer like this with my silhouette gun, shooting no neck tension. I finally let the "shoot with neck tension crowd" beat some sense into me and simply going to .001 neck tension stopped the flyers altogether. I don't know what your load is exactly, but just a thought. Only other thing that can cause that is an airpocket if you didn't flinch.

[bangerjim]

The ONLY time I weight boolits is either with a new mold or I change the alloy mix drastically. Once I know the weight, I write it down on a slip of paper and put it in the mold storage box. End of weigh scale usage!

I am not one to weigh every boolit and worry about a flier or two. All the shooting I do plinking and target practice with water bottles and paper. That's all. No hunting. No match grade shooting, No contests. Only fun with friends. It's like a round of golf, the only competitor I have is MYSELF and MY SKILLS and not the people I am playing with or blaming the weight variation/accuracy of the clubs because there was blade of grass or tiny piece of dirt on the clubs or balls. It's all ME.

Your body movement/position or surrounding conditions/weather/wind will relate to good or bad shooting, not the tiny miniscule weight variances in boolits you cast.

Have fun

bangerjim

[Larry Gibson]

I see you've got the usual responses referencing that weight sorting isn't necessary. Well, for the usual 1 1/2 - 2 moa 3 or 5 shot groups most seem satisfied with weight sorting cast bullets isn't necessary, if you cast good quality bullets. Also as seen many just kiss off flyers such as yours as a twitch or bad shot even though the shot was called good. All that is fine and I shoot a lot of such bullet/loads in numerous rifles just for fun.

However, when I'm serious about getting the best accuracy then weight sorting is a must along with casting excellent (that's different from "good") bullets with a proven alloy. If you want the accuracy that the 4 shots show a potential for then I suggest you also weight sort.....properly. Here is a response i posted some time back that may give you some insightful information.

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.



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.



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.

With such weight sorting I am able to consistently shoot 5 and 10 shot groups shown here even though I was shooting for score on the CBA target not group. Lower left target is sighter target. Bottom right target (the 10 shot group) is actually 2 different 5 shot groups. A wind came up out of 4-5 o'clock and I did not correct for it as I wanted to see how much it affected the bullet. The group enlargement toward 9 o'clock is the result.

[high standard 40]

Larry, I use the same process you do. It has served me well. We don't all have the same accuracy requirements. But I have found weight sorting to be a valuable tool to achieve optimal accuracy.

[Harter66]

In the vein of weigh sorting . I had a rifle that with a 1.5 gr difference in case weight , single source of brass , I water weighed too , that would not just toss one out but put it in a group of its own 18" away . This wasn't some high end precision $5000 rifle either it was a plain Jane left hand 1965 Savage 06' .

[indian joe]

Not shooting the kind of groups these other blokes are but I want to eliminate every excuse I possibly can
I weigh sort boolits any time I am serious - got a neat little digital scale and the job got a lot easier and quicker - as I proceed I stand em up in their weight groups on a flat board right near the weigh station - line em up in rows of 10 - 20 front to back -

so I have a lead boolit graph grows as I go along - definitely agree with Larry - no sign of a bell curve !!

Also think that a part of the variation in mine is coming from how I hold the mold (how hard do ya squeeze the handles as you pour) I get about 5% are well outside the average, (got slack on the handles and they are fatter or sprue plate screw came loose and we decided to pour a few more before fixing it - just dumb stuff)
Quality brass mold (CBE) gets me about half the variation in the main batch that I get with a LEE (difference between $25 and $150 or difference between aluminium and brass?) - not a pick on LEE - cant beat em value for money and they work good for a lot of shooting.

No bell curve at my place!

[freedom475]

Bad base makes sense but these were checked. Could a badly applied check or the check flying off cause it?

Well I believe that this is your answer...Yes, a gas check poorly applied, or flying off during flight is not good for accuracy. Most BPCR matches that I am familiar with do not allow the use of Gas-checks. Annealing the checks might help, but using a mold that does not require them will be best.