Cast Bullet Weight Variations

[Blacktail 8541]

What Do You Consider Acceptable Weight Variations In Your Cast Bullets Before You Cull Them, Or Do You Check Weights? 90 % Of The First 100 I Cast Were Within 1.5 Grains With The Last 10% Opening The Spread To 2.4 Grains. Your Opinions Appreciated.

[anachronism]

A lot really depends on the weight of the bullet you're casting. I can usually hold 180 gr. LBTs to about 1/2, to maybe a 3/4 grain variance from heaviest to lightest. I start remelting at 1 grain variance. This is not 1 gr. +/-, this is 1/2 grain +/-. I'll let 300 grainers go to about 1.5 gr. +/- before remelting. I only ladle cast nowadays, I've never figured out how to get consistent results with those new-fangled bottom pour contraptions. The level of consistency I require is really unnecessary for everyday shooting. 1 to 1-1/2 % should do you fine, and I know guys who are okay with 5%. And I know some who don't even weigh bullets at all.

[Blacktail 8541]

Sorry The Weight Of The Bullet Naked Is 242.5 For A 250 Grain Gc 41 Mag.

[BruceB]

Ol' Scrooge, here...

On a number of occasions, I have weighed every single bullet in a large run, like 800 or 1000 bullets. My PACT electronic scale makes such evolutions rather painless, and the experience taught me a few things.

One such thing learned, was that weighing my production is pretty much pointless. My regular visual inspection rejects more bullets than does weighing, and the rejects are few with most of my moulds. By this, I mean that some bullets which weigh-in nicely within whatever tolerance I allow on a given occasion would be rejected by visual inspection.

I do weigh some smaller lots on occasion, mostly out of curiosity. Based on considerable history in doing this, I now expect my bullets of around 200 grains to have a MAXIMUM extreme spread in weight of about one grain, and bullets in the 130-grain area to have an ES of about 1/2 grain. My RCBS 365-grain .416s typically show a max ES of less than one grain, and likewise for my now-departed RCBS .50-515s.

All these are bottom-poured with the ProMelt set at its highest temp, about 870 degrees. Those RCBS singles are wonderful moulds, but most of the others are cast from 2-cavity or 4-cavity moulds of various manufacture, and they still deliver bullets which are extremely consistent in weight, even including 2-cavity Lees.

I firmly believe that the HOT casting temp allows better fill-out of the bullets than cooler temperatures, at least with wheelweight alloy, and I do the high-temp routine all the time. For instance, rounded bases are very rare in my casting sessions. I recall a day not long ago, when I eyeballed over 1000 RCBS 44-250KT boolits under magnification, and didn't reject a single one! THAT is consistency in fill-out, believe me, because I'm quite fussy about flaws. (Did sundog ever mention how much he [and I] like RCBS molds???)

IF I intended to shoot some super-high-class ego-stretchin' match or other, I suppose that weighing the bullets might be in order. However, I shoot for fun and relaxation, and my regular way of casting is fine for what I do.

[Blacktail 8541]

Bruce I tried your technique for speed casting just to try to keep the weight variation to a min. But it is hard to do with a ladel! Right now it is a coleman stove and 10 lb pot. I'm waiting for my rcbs to show up. I may be asking to much of myself when I am just starting out but that is the way I am. My standard spread as of right now is less tha a half grain either way with an ocational low weight that isi/2 to 3/4 grain lower. they average about 1 out of 8.

[Blacktail 8541]

Forgot to add that my mix at this time is 50/50 wheel weight and lino. most of my shooting is just for fun now , Got out of the compitions a while back, but still never have to much accuracy for my taste.

[NVcurmudgeon]

BruceB, I endorse your idea that visual inspection will cull out about as many as weighing will. Recently, sorting nearly 200 Lyman 311284 boolits given me by a generous friend, I found THREE boolits outside a 1% weight range. Also, there were TWO with very minor visual flaws. (I only weight sort boolits when working up loads or loading for competition. Normally, for fun shooting my castings get a visual inspection only and still manage to outshoot me.) I conclude that a merciless visual inspection will likely do as much good as weighing.

[Dale53]

My method depends on what I am going to use the bullet for. For typical revolver and pistol bullets, I visually cull. I am pretty particular and won't use a rounded base. However, when the mould and metal "start running" nearly everything comes out well. Anything that doesn't meet the cut goes immediately into the pot.

However, for Schuetzen bench use, it REQUIRES as near a perfect bullet as possible to be competitive. 1/2 minute accuracy is the requirement. For these, I weigh every bullet. I have an RCBS electronic scale so it isn't a terrible chore. My standards are now +or- .2 grain with a 204 gr bullet. Hopefully, I will get that even closer (at least, that is my wish). When I was shooting BPCR Silhouette, my standard for 422 gr. bullets were +or- .6 of a grain.

Dale53

[44man]

I go along with Bruce on this. I have spent untold hours weighing boolits. I have not found enough difference in groups between different weights to make the effort worth the trouble. If your casting technique is good, the boolits are all good except any that have visual defects. Maybe for bench rest, it would help, but for what most of us do, it is a waste of time.
It is the way you cast that determines the reject rate. If you are tossing a bunch back in the pot, you are doing something wrong.

[Blacktail 8541]

Very few visual defects, my speed is not real fast so the boolits are not getting frosty. no wrinkles either, So my worry if you want to call it that is group size as related to bullet weight. I'm new to casting not cast bullets and really enjoying my new past time. It is very relaxing.

[sundog]

I weigh match boolits. Since I am already weighing them, I sort by .1 gr (yea, one tenth) and leave them in segregated batches. The spread is sometimes as much as one grain for 180ish weight boolits. I'll generally get enough at .1 intervals for at least a couple three batches of ammo (70 at a time for a match). Left overs are used for bbl warmers. This has done two things; reduced flyers to virtually zero, and tightened groups. Seems like + or - .5 would do just about the same. What I am really looking for is those that do not get visually culled, but are light weights. Those babys have a hidden void, and almost guaranteed, they'll produce a flyer. Hmmm, just thought of an experiment to test this. Maybe next batch I weigh I'll keep some out, mark'em and shoot with known good'uns for comparison. If I do, range report will follow.

There's one other batch of boolits that I weight. .22s. You gotta be ruthless in culling these little itty bitty boolits. Again, since they're going across the scale anyway, they get sorted by .1 gr. Felix and I have been working a little project here lately and the mould in use is producing some outstanding results with the majority of the boolits dropping around 59, + or - .2, from a 2 cavity mould. They shoot purdy durn good, too. Anything outside that range is a cull and goes in the recylce can. When they're being shot through a Douglas air gage bbl, and the rest of the gun is up to task like it is, it's worth it. Not bad either in the little .222 Sako carbine.

Clean, well tuned moulds, and a hot, hot, hot melt, and a good casting technique will make good boolits well within an accetable range. My best and most consistent boolits, hands down, are dipper poured. Well filled out and square, flat bases. The base is important, even it's getting GC'd. I have a Lyman dipper that I've been using for years that is cared for as well as any of my moulds, especially the spout.

Okay, so is all this all way too anal? Not when you shoot itty bitty groups, consistently.

Plinking boolits for the grandkids get poured, lubed and loaded. That's it. Get a bad one at the casting bench, it goes back in the pot. sundog

[44man]

Yes, the smaller the boolit, the more critical it is. With heavy boolits and large bores a small variation will not be noticed. Like I said, bench rest shooters need extreme measures but someone banging away with a .357 or .44 and up will never notice a few grains. Even in the 45-70 for BPCR, I used to weigh all of them. Never seen a difference if I didn't. A grain or so in that big of a boolit just isn't worth the trouble.

[joeb33050]

I weigh every one, and have records of 11374 bullets in 104 batches, average 110 bullets cast per batch, all with a ladle.
I throw out any bullet weighing more than .5 grain from the average, generally 1-3 bullets per batch.
Less these outliers, all the bullets I cast are within +/-.5 grain of the average, and generally the spread will be .4-.5 grains.Thus, 311299, high is 208.2, low is 207.8 grains.
The average S.D. is .145 gr., high S.D. is .294 gr., low S.D. is .068 gr.
Variation is NOT a function of bullet weight.
Summary: I (and you) can cast bullets of any weight from 40-500 grains that vary no more than +/-.5 grains for the batch. I weigh for the outliers, the bullet that's 1.8 grains light or heavy, that WILL shoot out of the group.
I CANNOT demontrate that bullets that weigh EX: 208.2-208.7 grains shoot larger groups than bullets that weigh exactly 208.4 grains.
I'd be happy to send my EXCEL spreadsheet of bullet weights to anyone interested.
joe b.

[pepperodin]

I am reading this old thread because it is relevant to my question. I did the math on 50 of 238 bullets cast using a Lyman 452424 mold. Lyman says these are 255 grain bullets (for Colt 45). Here is what I found:
N = 50
Mean = 242.004
SD = 0.938
The first thing I notice is the mean weight is 13 grains less than Lyman’s advertised 255 grains. If it matters, I used Lyman #2 alloy and poured at 750 degrees with a PID controlled pot. The bullets are all clean with sharp edges. I sized all of them to .452 before weighing them. The SD of .94 isn’t so bad. It’s the mean weight of the bullets being 13 grains lighter than the expected 255 grains that I am wondering about. Any idea what’s going on here? Ken

[trapper9260]

I say pepperodin do not worry about the weight you getting,when you load them and get them to shoot the way you want keep that mix . For the weight you get is looking like less lead in the mix. But if it works for what you looking to do then work with it.

[gwpercle]

Heavy 41 cal. at handgun range , unless I'm shooting for big money prizes , they don't get weighed.
Keep only boolits that are visually very good (very near perfect). I like complete fill-out with perfect bases.
I do pressure cast mine with a ladle that has a side spout and find this method gives me better consistency than the bottom pour pot ,
I can't tell any difference in accuracy.
Rifle boolits to be used at long range are another story.
Gary

[largom]

I don't shoot competition, I shoot for fun. But fun for me is trying to shoot one hole groups with cast boolits and a hunting rifle. So, I weigh all of my boolits and my brass also. Separate by 1/2 gr. Is this necessary? No, but I enjoy messing around with my handloads. I try to make my cartridges as perfect as possible. With old age I need all of the help I can get.
Larry

[adam_mac84]

I am following closely and would like to investigate this as well. I just pour, coat, and cull REALLY nasty ones at the bench to the re-melt pile.

I can shoot a 96-98 pretty routinely from 15 yards in a B8 with 10 shot group, that's probably as good as I will get