Weighing bullets question?

[Jerry Lester]

I spent a while weighing my 32 magnum boolits last night. This 95g Saeco SWC mould is dropping them on average at around 97.5g which is fine with me.

My question is this...

I decided that + or - .4g should be good enough for consistent accuracy seeing how 100g XTP-HP's can vary as much as + or - .5g or more. Most of mine are dropping between 97.3, and 97.7 grains, but a few are a tad farther off, and of course, every once in a while I'll weigh one that won't even raise the beam[smilie=1: . I'm figuring a void in those boolits?

Is + or - .4g good enough(close enough)? That leaves me with my boolits having an extreme weight spread of .8g. I'm figuring it's fine, but would like to have the experienced opinions of you seasoned casters on the matter before I start sizing 2000+ boolits after individually weighing each one:roll: :mrgreen: .

[Guido4198]

I try not to tell others what they need to do, but since you asked, I'll share my criteria for what it's worth. For heavy bullets...200 gn. or more...I'll accept up to 0.5 gn. dispersion in either direction. For lighter weights, I tighten that a bit. I just cast a mess of 25 calibers, (Lyman 257464) for my 250 Savage. I kept my range to 0.1 gn. for those. My keepers are: 91.3-91.4 gns. 50/50 Pb/WW.

[grumpy one]

This is a question I want to resolve, but am finding it difficult. I've found that my pretty sloppy casting technique gives a considerable range of weights - after discarding the ones with visible faults, my 311291s vary over about 1.5 grains. They also vary a bit in diameter. Despite careful loading technique, group sizes for the same load vary too - bad 5 shot groups are three times the size of good ones, but often three of the five bullets go through the same hole in the bad groups. My current suspicion is bullet variability as the culprit. I've found my 311255 castings only vary by half a grain - a third as much as the 311291s - and group sizes are considerably more consistent.

I'm embarking on a series of tests where I match bullets for both weight and diameter, rather than just weight, because I've found matching them for weight doesn't entirely cure the problem (though it seems to improve it somewhat). The key point is that good castings don't vary anywhere near as much as mine do, either in weight or diameter.

Like you, I suspect that my least-dense bullets (the ones with low weight and large diameter) either have patches of porosity or voids in them. Some of the ones I reject either have holes or cloudy patches on the surface (I'm too lazy to get my alloy really clean), which is part of the basis for this suspicion, along with reasoning that variations in bullet density must have some cause. Unfortunately variations in sprue cutting outcomes have to be factored in there, and can have a biggish effect.

In this situation there are two solutions available. One is to improve the quality of my bullets in the hope that the problem will go away. The other is to experiment with bullets having various known faults and see what happens. I'm following the latter approach for now, mainly as a way to use up my collection of lousy bullet castings.

[Junior1942]

Sort 'em by Standard Deviation. See http://www.castbullet.com/shooting/standard.htm

[grumpy one]

Junior, as a first trial I have it in mind to shoot six groups, all with 311291.
The first three will weigh 178.5 grains (+ or - .25 grain)
Group 1: 0.311" as cast driving band diameter (+ or - .0002)
Group 2: 0.3114"
Group 3: 0.3118"
The second three will weigh 179 grains (+ or - .25 grain)
Group 4: 0.311"
Group 5: 0.3115"
Group 6: 0.312"
The wider spread on the second batch is because it turns out the diameter varies more in my 179 grain bullets than in my 178.5 grain bullets.

The outcome from this test might tell me that bullets with high density (groups 1 and 4) shoot better than those with low density (groups 3 and 6). It might even tell me that denser bullets of the same diameter (groups 4, 5 and 6) shoot better than less dense bullets (groups 1, 2 and 3). More likely, though, bullets will scatter around the target with no obvious cause, as usual.

I intend to shoot these groups with 20 grains 4759 in my K98 30-06, because I need to size to 0.312 to shoot them in my 30-30, and most of these bullets are too small to size 0.312. The 30-06 likes 0.311 bullet sizing. Unfortunately results tend to be more erratic in the 30-06 than the 30-30, so the odds are against me getting any useful results. However it is fairly painless shooting 20 grains of 4759 in the K98, so perhaps I'll have a nice day at the range.

Completely unnecessary warning note: 20 grains 4759 is my best accuracy load in the 30-06. Please don't try it in a 30-30. Listed maximum load of 4759 for a 30-30 is 18-18.5. 20 grains might mean a faceful of metal - I'm not silly enough to find out. I have tried 19, and some of the primer found its way into the firing pin hole in the bolt.

[Jerry Lester]

Interesting! Keep us posted on your results please...

[Dale53]

I cast for many different guns. I use a single cavity for my precision bench rest Schuetzen rifle (.32 Caliber). It was suggested by ASSRA Schuetzenmeister, Jim Borton, that I get the Cabine Tree clamping mould handle to reduce the weight differences in my bullets. I did so and by jingo it did reduce the differences. It clamps the mould together the same amount (and holds them together) while casting. Those slight differences in diameter (almost too small to measure but large enough to weigh) caused by varying pressure on the mould handles make the difference.

When casting for my pistols and revolvers I use the conventional handles and multiple cavity moulds. My weight tolerance with those bullets is plus or minus one0-half grain.

http://www.castingstuff.com/cabinetree_loading_products.htm

Works for me!

Dale53

[Guido4198]

After doing all the bullet sorting,measuring,weighing...
Remember to put at least that much effort into your cases. My research into using a group of cases that have been "match prep'd"...versus random mix, w/ out trimming, etc...shows a considerable affect on group size. If your goal is to compare bullet differences...you have to eliminate "case difference effects" as much as possible.

[Bass Ackward]

Grumpy,

I believe that, as usual, we create our own problems. And it depends on our ability to diagnose the problem to actually correct the end result. I can't possibly cover all the options because I don't know them all. I catagorize problems resulting from bad bullets to break down into two catagories for me. Pressure problem related and stabilization related.

When a bullet sizes, and all rifles are sizers, it depends on where our bullet problem actually is. If it's in the base which is the steering wheel of the bullet, a slower powder can be gentler on more bullets and allow more bullets to be successful. When your bullet's size is larger than bore, that aids inertia and puts more resistance to forward motion. So .... pressure has more opportunity to work on the base colapsing the void and throwing the base out of square, which is where most molding defects rise too. Smaller sizing with faster powders can improve groups overall. You might not have most in one hole, but the fliers won't be as dispersed either. So it turns out to be a compromise thing. Harder bullets can help here if the balance to strengthen the base isn't countered by increased resistance to forward motion.

Which is one of the many reasons I chose my name. I go rock hard for slow stuff and soften for faster velocity. Always Bass Ackward. I use that same charge with a 311284 that is actually .3075 in places in a .308 bore. I size the check on at .3095 which is a tight fit. But that bullet sucks if you try to push it. Now if it were bigger, I expect it would do better. It will hold 1/2 slow fire.

Then there is the problem of stabilization. If you choose a faster velocity load with slower powders, voids far enough away to not ruin the base, may ruin balance. These may not be as noticeable, if higher RPMs stabilize them better. I have taken 35 caliber bullets that look like they have erosion up the sides (good bases) and vary by 4 or 5 grains and still held 1 1/2" 10 shots groups. Since a 35 has a slow rate of twist for the bullet weight, if I slow them down, or when they move far enough down range to drop below that magic point, they disperse everywhere. But you have to shoot farther to see this effect.

My point is that I think you will find that if you change load or any load perameter, your test results may be entirely different. Depending on the problem you are creating, the varibles of that launching system, and the method you use to solve it.

[wills]

http://www.public.iastate.edu/~jessie/PPB/Stats/

[felix]

Wills, the principles for the analysis of variance points more to those who can't see the forest because of the noise presented by the trees. We really don't have that problem in seeing the grouping ability of a particular load versus another. If it is that close over several outings in differing conditions, then we might have a problem. However, that problem is solved by the amount of components we have in stock. Most of us would pick the load having the greatest inventory of components, but some of us would pick the other to intentionally eradicate the inventory because no more can be had anyway. ... felix

[grumpy one]

Bass, I think I need to do some work on which are the most sensitive factors in causing the variability I'm getting. I know about some of the things that vary, but I don't know whether they matter. If small voids or porous areas within the bullet are a big part of what's happening to me, I hope the experiment I described will point that way. I finally got around to weighing my cases today, and found I had two different batches of 30-30 cases mixed up together, with one batch five to six grains heavier than the other, so I've culled one batch. The 30-06 cases were homogeneous, so I didn't gain anything there. I shoot 311291 in the 30-06, and C309-170-F in the 30-30, and I seem to get more variability in weight and size in the 311291, so I may gain something from culling bullets more stringently than in the past - I may find out from the experiment.

I'm sticking to a mid-range hardness (water dropped 3%/5%) for now because if I use very hard bullets I'll conceal the variables I need to investigate. One of the things that worries me a bit is I suspect that water dropped bullets vary quite a bit in hardness when I make them, because the amount of time it takes me to get them out of the mould and into the bucket varies. Since I seem to have a strange compulsion to push bullets about as hard as I can, variable hardness is a bad feature for getting consistent accuracy results - most likely some of the bases collapse and others don't, for what is theoretically the same bullet specification.

The stabilization question is a major reason for me sticking to 55 yards - if I ever get the short-range situation under control, it will be time to move out further and introduce a bunch of additional variables, like how well the bullet flies.

If I ever figure out what matters and what doesn't, I hope to be able to back off on what I do and don't try to control. In the end I'd be quite happy with full loads that shoot into 2 or 2.5 inches at 110 yards - so long as they do so consistently. I'd be likely to stop doing things on the loading bench if I can get that kind of accuracy without doing them. However I have to get the situation under control before I can make that kind of investigation.

[lovedogs]

Jerry... you've raised a question that sometimes baffles me. Conventional wisdom and common sense would tell us that weight differences would make a lot of difference. Surely, if they vary too much it will have an effect. But let me relate a story to you.

To begin with, I don't have any experience with small bullets. My smallest bullets are 240 gr. .44's. A couple years ago I got in to shooting silhouettes with a .45-70. We were required to shoot cast lead bullets and I hadn't cast any bullets for years so I didn't have any equipment yet. My first year I had to buy custom-cast bullets. Darn expensive way to go! By the next year I'd gotten all the stuff together to make my own bullets.

While shooting the mail-order bullets I'd found that the 500 gr. bullets I was buying varied by as much as 7 gr. I called the supplier to complain. He told me it wouldn't make any difference, that this was a small percentage of the total bullet weight and they'd shoot just fine. Being new at this I believed him and just kept shooting them. And he was right. They shot great! One inch 100 groups were common and I used them in matches shooting out to a half-mile. No problem.

Then when I started casting my own I found I could cast much better bullets and the weight variance was much smaller. My good ones are within one grain. But for the life of me I couldn't see where they shot any better than that other guys. They all shot great!

For matches I do sort bullets and use only the best ones that are all within one grain of each other. But my experience has been that if they have no visual defects and the bases are sharp they all shoot really great. In my opinion, the sharp base is the most important part. I've found that if they drop out of the mould with a sharp base they will weigh so close it won't make any difference, barring any other visual defect, of course.

That's my take, for whatever it's worth.

[Wayne Smith]

I spent a while weighing my 32 magnum boolits last night. This 95g Saeco SWC mould is dropping them on average at around 97.5g which is fine with me.

My question is this...

I decided that + or - .4g should be good enough for consistent accuracy seeing how 100g XTP-HP's can vary as much as + or - .5g or more. Most of mine are dropping between 97.3, and 97.7 grains, but a few are a tad farther off, and of course, every once in a while I'll weigh one that won't even raise the beam[smilie=1: . I'm figuring a void in those boolits?

Is + or - .4g good enough(close enough)? That leaves me with my boolits having an extreme weight spread of .8g. I'm figuring it's fine, but would like to have the experienced opinions of you seasoned casters on the matter before I start sizing 2000+ boolits after individually weighing each one:roll: :mrgreen: .

Jerry, are you shooting them out of a rifle or a pistol? It makes a difference, unless you are planning to shoot a revolver to 100 or so yds. Longer range is obviously more demanding on a bullet, and thus you need more controls. Short range pistol/revolver shooting is much less demanding and the fit of the bullet to the gun is much more important than the exact weight of the bullet.

[Jerry Lester]

Jerry, are you shooting them out of a rifle or a pistol? It makes a difference, unless you are planning to shoot a revolver to 100 or so yds. Longer range is obviously more demanding on a bullet, and thus you need more controls. Short range pistol/revolver shooting is much less demanding and the fit of the bullet to the gun is much more important than the exact weight of the bullet.

I'm shooting them from a custom 32 magnum Single Six. I try to keep shots at game within 50 yards, but I regularly practice with my revolvers at 100+ yards.

[joeb33050]

I weigh (almost) every bullet I cast. For a while now I've kept a record in EXCEL. Until the past month or so I would have said that the standard deviation = variability measure of bullets is independent of the weight-that small bullets and heavy bullets vary about the same. Lately I've had a lot of trouble casting bullets out of WW for the 45/70. I'm going to finish my WW and quit forever, I find that bought 25:1 or Lino makes such better bullets easier that it isn't worth the aggravation for me any more. Talking rifle bullets here.
I have records on 13,072 bullets cast in an average lot size of 109 bullets per session.
The heaviest bullet cast was 445.3 grains, the lightest 58.5 grains.
The average standard deviation was .148 grains, the largest-yesterday with a 45/70 bullet, was .305 grains; the smallest standard deviation was .062 grains.
Some bullets some days weigh way over or under, I use these for sighters/foulers.
I don't count these because I am able to cast bullets with the vast majority +/- .5 grains.
My opinion is that there's something wrong if I can't cast bullets +/- .5 grain in any lot any weight.
My sighters/foulers make embarrasingly small groups with no strangers that I can remember.
I don't think that segregating bullets finer than a group +/- .5 grains helps accuracy. I primarily weigh bullets to find that VERY light bullet that shows up now and then, even after passing 4X visual inspection. These DO seem to shoot a little wild.
That's my story, and ....
joe b.

[Wayne Smith]

Jerry. do up a bunch that you've carefully weighed and sorted, and another bunch that you shot as cast, only visually sorting and tossing. Shot those two for accuracy, and I'll bet you don't find a significant difference. One or two fliers per 50, I'll bet. Those are the ones with voids that you didn't see. That is, assuming your casting process is adequate.

[Magnum Mike]

I weigh all of my boolits. I shoot a lot that have some visual defects but otherwise meet my weight requirement. BTW, i weighed a bunch of full length gas checked bullets to determine what their weight tolerance was/is. The results were surprising....

[Idaho Sharpshooter]

if you are shooting them in a pistol, it doesn't really do much good, IMHO. Bullseye or PPC maybe...but unless the targets are small ring bullseyes it is a waste of time.
I shoot CAS, and any load that shoots under 5" at 25 yards is overkill. My partner finished fourth at EOT this year. He doesn't know within 3gr what his bullets weigh.

Rich

[georgeld]

I went that route a few yrs ago.

Then fired about a hundred real careful five shot groups in the '06, 30/30 and a couple revolvers and discovered even the worst cast bullets shot better groups than I was capable of shooting myself.

So I quit messing with it and started casting a lot more by stashing/trading those singles for six cavity Lee's and just making production runs of as long as I can stand sitting there doing it for about three or four sessions to fill a two gallon bucket.

After each session, or between each refilling of the pot I'll quickly eyeball sort what's been cast since the last time. Usually a handfull or three.

When they go thru the sizer if n when I do that. And again as they go into the case they get another eyeball inspection. Anything I see not good enough goes into the pot, or scrap bucket til next time. But, unless a notion hits, I don't weigh them at all and get along with them just fine.

I've fairly well gotten away from rifle shooting them and burning many times as many in the wheel guns plinking and practicing.

I am strongly thinking about casting some 12ga balls for a hog hunt to see how they'll work. Take the plug out of the 1100 should make a wicked up close hog buster. Althougth I don't have a 12ga loader set up it's been in mind for years since I do have a Lee loadall for 20ga that could be updated pretty easy.

Anyone have some suggestions for doing this? I've got a single Dixie RB mold for .715". Never been heated up yet either. How would this work patched and pressed into 12ga hulls? OR would I be blowing the gun up and my head off?


Could anyone tell me what a ball this size would weigh right off hand without having to make some and weigh 'em?

Thanks fella's,