cast bullets - do they usually vary so much?

[Ratbelly]

I'm new to reloading for handguns but I've been reloading for rifles maybe three or four years now. I've got an assortment of cast bullets that came with my 500.
One box is still the factory box so I know what they are 440gr. WFNGC, but none of them actually weigh 440gr. Most are about 436gr. I realize there might be a little variance due to the lube and just being cast.
The other two containers I have don't have any label. One box is un-lubed and weighs randomly between 452gr and 456gr with most being closer to 452gr. Am I to assume these are supposed to be 450gr?
The other box varies from 448gr to 452gr and they are lubed, so would these be 450gr?
They all seem to be the WFNGC bullet.

 

[mkk41]

The 2 common alloying metals in bullets are tin and antimony , neither of which are as heavy as lead. Most bullet mould weights are given when cast from Lyman #2 alloy , though some might be when cast from pure lead. Straight wheelweights weigh even less than pure lead or #2. Not even sure if there is an official 'receipe' for wheelweights. Your results may vary.

 

[Ratbelly]

Maybe I need to rephrase my question, I have two tupperware containers of bullets. How do I tell what grain they are if they vary two to four grains? Do I just round up or down to the closest listed weight?

They are factory cast bullets with gas checks.

 

[lebomm]

At that weight, 2-4 grains is less than 1%. I don't think I'd concern myself with that until I started loading to redline or above. I'd call 'em 450s and load 'em below max. hth

Larry

 

[Rule3]

Yes cast bullets will vary in weight. Especially large heavier ones like yours and then with gas checks. A 4 gr variance with a bullet weighing 450 grs to me would be insignificant.

So load them with data for 440 and the others 450

You can use data for the 450 gr bullets for the 440's they will just gain a little more velocity. Not the other way around.

 

[Skip Sackett]

Maybe I need to rephrase my question, I have two tupperware containers of bullets. How do I tell what grain they are if they vary two to four grains? Do I just round up or down to the closest listed weight?

They are factory cast bullets with gas checks.

In answer to your question, yes. Pick a mean and go from there. Every cavity of a mould has tolerances, everything made by man has tolerances. Nothing you do is completely perfect either.

Casting is an art rather than a complete science. Oh, there are specifics but, alloy can vary a lot.

In my experience, wheel weights are heavier than Lyman #2 but lighter than pure lead.

FWIW, don't sweat a 2-4gr difference in bullet weight. Check some of those high priced jacketed ones you have lying around!

 

[Alk8944]

Maybe I need to rephrase my question, I have two tupperware containers of bullets. How do I tell what grain they are if they vary two to four grains? Do I just round up or down to the closest listed weight?

They are factory cast bullets with gas checks.

Ratbelly,

Yes, it is common for cast bullets of the same nominal weight, and from the same maker/caster, to vary by several grains. Typically the vast majority of commercial bullets are machine cast in a "Master-Caster" machine using several sets of mould blocks from Magma Engineering. As smith crazy pointed out, everything made by man has minute variations from specification know as tolerances. Tolerances specify how far from the specification the item may vary and still be considered acceptable. If mould cavity depth varies by .005-.010" (common) and the diameter by .002-.004 (again, common) the bullets will vary by several grains between moulds or cavities.

When you add the other factors which affect bullet weight, alloy, casting temperature, etc. If you consider all this it is amazing they are so consistent. As lebomm referenced, +/- variation 1% is considered acceptable, even for match grade cast or swaged lead bullets.

So far as load data is concerned, use data for the nominal weight of the bullet. If they are supposed to be 250gr and they really weigh 265, then if loading maximum listed loads use the 265 data. If within +/- 5 gr. don't worry about it.

Don't be surprised if the next box of the 440s runs 442-445 from the same maker. So far as what to call them for labeling purposes, whatever the maker said they are. Even if you are chronographing and calculation bullet energy the slight variation will tend to take care of itself in average velocity. Even with 1000 FPE a 1% variation in weight will only vary energy by roughly the same amount, or 10 FPE. The animal, paper target or beer can won't be able to tell the difference, and neither will you.

In the realm of shooting cast bullets, worrying about such minor details is "Straining gnats".

 

[ohiococonut]

Check some of those high priced jacketed ones you have lying around!

Oh sure Skip, now you're going to have him weighing all of his bullets

Ratbelly don't get to concerned about the weight difference. Just round out the bullet weights.
There are ways to extrapolate different powder charges for different weight bullets but I doubt you'll see much difference with the weights your using.

 

[Titegroups]

I'd weigh all of them and sort them in groups by tenths of grains. Then sub divide the groups by diameter, also by tenths. When you find groups that contain only one of each you have arrived.

 

[scattershot]

I would just round up to the nearest whole number, and call it good. That's actually a pretty small variation, and I doubt most folks could shoot the difference anyway.

 

[fredj338]

The larger the bullet the greater the variation. With care during casting, you can get them to less than 1% variation, but it requries a constant temp & casting rythm & careful sorting. I only sort my hunting & long range bullets. Anything greater than 1% weight variation goes back to the pot.

 

[Forrest r]

The bullet diameter is far more critical than the bullets 1%+/- variance in weight.

I weigh my cast bullets 1 trigger pull at a time.

 

[old tanker]

If you were taking your Sharps out to Wyoming to shoot the Wasserburger Mile, I'd recommend you weigh and sort bullets. With a handgun, I was able to go clean on 200 meter rams in revolver class casting my own and tossing back only those that were visually defective. Not filled out, bad bases, etc. Good technique with a ladle will do better than a bottom pour pot.

 

[fredj338]

If you were taking your Sharps out to Wyoming to shoot the Wasserburger Mile, I'd recommend you weigh and sort bullets. With a handgun, I was able to go clean on 200 meter rams in revolver class casting my own and tossing back only those that were visually defective. Not filled out, bad bases, etc. Good technique with a ladle will do better than a bottom pour pot.

Maybe, but a BP pot is easier to get good bullet from IME. I only weigh the long range stuff, looking for extremem wt variation that might signal an internal void. All I shot when I was shooting metsil was lead bulelts in my 8" DW 44mag. 200m rams were never safe.