Bullit Wt spread?

[wistlepig1]

Can someone tell me with is a realistic spread in Wt. on cast 22 Cal. thanks martin

[montana_charlie]

a realistic spread in Wt.
I only cast for BPCR, and my bullet designs range from 500 to 560 grains, and the moulds are all single cavity types.
The bullet I am using right now weighs a nominal 540 grains.
I always cast fifty per session, and cull those which have any physical flaws.

The scale reading is never more than 543, nor lighter than 542 when weighing those fifty.

It may not fit your definition of 'realistic', but it is real.
CM

[Bullshop]

As luck would have it I just today cast some 22's. A random sample of about 10 had an extream spread of .5gn. About 6 of them were the same weight. It only takes one poor casting to open the spread. These were cast in a six cavity mold made for me by Walt Melander about 15 years ago. These were cast with WW alloy with about .5% tin added. Also add at about 20/1 (ww/chilled shot) and quenched from the mold. Tomorrow they will test at about bhn-24.
BIC/BS

[BABore]

In working with Felix, on my new 226-47 GC design, I had the luxury of weighing and sorting several 100 boolits. All were cast with a 4C mold from a 50/50 WW-Pb alloy, using a Rowell #1 ladle. Once the mold was broken in, the weight spread was running +/- 0.15 grains. For accuracy testing I was selecting the heaviest, exact weight boolits. The lowest weight boolits were remelted. Those varying +/- 0.1 grains were used as foulers and general plinking fodder.

What is an allowable weight variation in 30-45 caliber boolits is not really acceptable for 22 cal pills. Even a minor air pocket or rounded band will cause flyers and out of round groups.

[Calamity Jake]

.2 total spread is all I allow on my 22s and 25s

[felix]

Yes, yes, select as above using boolits from one casting session. Then separate the selected into separate piles with ZERO weight variation for three piles: -0.1; 0.0; +0.1.... Each pile independently will give the same group as one another. The batch accuracy will then depend on the alloy mix from batch to batch, not on the separate piles from one batch. ... felix

Personal reaction to recoil is the determining factor using larger calibers, making the boolit variation less critical. Naturally, this assumes you can see the target the same way first and foremost. ... felix

[Bullshop]

Oh my mistake I understood the question to be what can be expected in casting not what is acceptable.
Personally I do not weigh or segregate 22's, I just shoot them. They are too difficult for me to see to segregate. When applying gas checks I look at the base and that is the only inspection they get.
Percantage of flyer's is small enough that I don't worry about it. If a fl yer opens a group to two inches at 100 yards I don't care I am not shooting BR. Most of my 22's are shot for fun and small game hunting. For a rabbit at 15 yards even that 2" @ 100 yard flyer will still be acceptable.
Doing the starched shirt inspection takes most of the fun out for me. I just cant see going through a BR inspection procedure then using them to make cans dance at the gravel pit.
Will my uninspected boolits shoot groups? Well maybe not quite what Felix may get with his full bore BR gun but for practical purposes not far from it either.
I had to laugh last week when I read something Mike V wrote here. He said something about realising that boolits were for shooting at things not groups so now he shoots at things and has much more fun.
BIC/BS

[joeb33050]

Can someone tell me with is a realistic spread in Wt. on cast 22 Cal. thanks martin
Based on my records of 20,377 bullets cast and weighed, here are some realistic truths for bullets with no visible defects from one cavity, well cast:
ALMOST every bullet will weigh average weight +/- .5 grains
ABOUT 99% of the bullets will weigh average weight +/- .3 grains
ABOUT 70% of the bullets will weigh average weight +.2-.1 or +.1-.2 grains. This means that if the average weight is 49.6 grains, about 70% will weigh EITHER 49.5-49.8 or 49.4-49.7 grains.

EVERY multi-cavity mold casts bullets of different weights from different cavities. EVERY one.

With extensive testing over many years I've never, that's NEVER, been able to detect accuracy differences between lots of bullets weighing xx.x grains and xx.x+/- .2 grains. Between lots weighing, for example, 197.0 grains and 197.0 +/-.2 grains. Nor have I read about a test showing an accuracy difference as a function of weight variation.
joe b.

[felix]

Correct, Joe! Weight variation is not the culprit. Instead it is the distribution of where and how big the holes are within each individual boolit. For swaged boolits/bullets the accuracy depends upon the "feel" of pressure during the swaging process. The projectiles are seperated into piles such that each member of a pile felt the same. ... felix

[NVcurmudgeon]

Correct, Joe! Weight variation is not the culprit. Instead it is the distribution of where and how big the holes are within each individual boolit. For swaged boolits/bullets the accuracy depends upon the "feel" of pressure during the swaging process. The projectiles are seperated into piles such that each member of a pile felt the same. ... felix

Felix, I shoot cast boolits BR only for load development or once a year group matches at the Nevada Cast Bullet Shoot. For these two purposes all castings with visible flaws are relegated to the "plinker" box and used for the majority of my shooting which is practice from field positions. The better looking castings are divided into piles based on weight. In the case of a CB with a nominal weight of 200 gr. and a single casting session of 400 castings the majority will fall into three piles. (Before starting to weigh castings those from each of the two cavities are separated, so that the following criteria apply to castings from ONE cavity.) For example 199.0 to 199.9, 200.0 to 200.9, and 201.0 to 201.9. There will be a very few castings that are heavier and lighter than the three "good" piles, sometimes by several grains. Rightly or wrongly, I believe that by putting aside the few 198 grain and 202 grain, or one or two with even wider spreads, I have reduced the likelihood of flyers. I believe that by using castings from the peak of the bell curve I believe that I have selected the best that I can cast. In actual use, following this procedure I have only had one flyer that I couldn't blame on the nut behind the buttplate in ten years. Am I spinning my wheels? With respect and curiousity, Bill

[felix]

Bill, the grin on your face after a "job done" is the only determination worth anything of merit, a'la' Bullshop Dan. No called fliers? Yep, that's the ultimate satisfaction game. The only thing you might do better is to throw all "plinkers" back into the pot. Why? Because components are too expensive anymore, and we are old and experienced enough not to have the need to resort to "second" class knowingly. ... felix

[sundog]

Visual inspection for load testing and development. They MUST have good bases and drive bands. No visible voids or wrinkling. I can tell in a very few rounds, sometimes as little as 3, if a combination has any potential.

I do weigh boolits for production work, but having an electronic scale makes quick work of it. I do not own a bench gun. I do have some guns that are quite accurate. So, culling the light weights seems to work for me. When I weigh a batch I general keep +/- 1% of weight after culling what I do not want.

I believe the light weight culls have defects, voids, inclusions, or other problems. It's the distribution of these anomolies (what Felix referred to) that create problems which show up in exponentially as the equipment gets better. If the gun and the shooter are capable of X MOA, then the boolit does not need to be any better than that. The fun is in the chase!

I will whole heartedly agree that as the boolits get smaller the culling needs to get better, especially if you are a good shooter and shooting good equipment, and know how to read the shooting conditions.