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Discussion Starter #1
How about some help from you math wizards out there.


If the weight of a single size 7-1/2 pellet with 2% Antimony is 1.3 grains.

How much would a single size 7-1/2 pellet with 6% Antimony weigh?

Thanks,
Ajax
 

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In a perfect world, 1.26 grains.

Assumptions:

Perfect sphere, 0.095 inches in diameter (probably a bad assumption.)

Exactly 94% pure lead, and 6% pure antimony, and nothing else in the alloy (also probably a bad assumption.)
 

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I like timb99's answer! I consistently get 1.25-1.26 grns from high quality 7 1/2 s. A big key though is the sizing. If truly 7.5, I get what timb99 says! For example, I recently went through a 15 bag order with same lot number of 8's! Bag after bag they ranged .94-.96! Glad I am anal, as these were really 8.5s! Tom Rhoads
 

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"same lot number of 8's! Bag after bag they ranged .94-.96! Glad I am anal, as these were really 8.5s!"

Thye were supposed to be #8? They should average 0.90

They averaged 0.95 ?

They were # 7.5, not #8.5. And they were very uniform #7.5, I might add.
 

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Sorry Mikie, but you are full of crap! See above on very accurate wt of 7.5 which is typically 1.25 grns of true high antimony shot! 8's are consistently 1.1 area and 8.5s run .93-.95! Have a nice day! Tom Rhoads
 

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Discussion Starter #7
The weight of a size 7-1/2 which is .095 was taken out of the Lyman number 5 Edition for pellets with 2% Antimony. The assumption of the pellet being round is correct. If Antimony is lighter but harder the size 7-1/2 with more Antimony should weigh less.

BTW Size 8's are listed at 1.1 with 2% Antimony and 8-1/2's run .09. These are weights, not sizes.

What would a single 7-1/2 pellet weigh with 6% Antimony. Or do you agree with timb99?

Thanks,
Ajax
 

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What you need to know is:

pure lead is 2,867.7844 grains/cubic inch and,
pure antimony is 1,690.3237 grains per cubic inch.

Further, the volume of a sphere is (4/3)*pi*r^3

Volume of a 0.095" diameter sphere is 0.0004489 in^3

if 94% of that volume is lead, you have 1.210 grains of lead
with the remaining 6% of the volume being antimony is 0.0455 grains of antimony.

total weight of 1.255 grains.

john
 

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YOU GUYS REALLY NEED TO GET OUT OF THE HOUSE MORE OFTEN.

Dig out of the snow and go shooting.....

It is really nice to know that we have folks that can and will answer many various questions about the sport. That is what makes this site so damn useful.


I salute all of you good folks. 66 degrees and a very clear blue sky. Headed for 74 next week.

Phil
 

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This gives new meaning to the arguments regarding 7.5's vs. 8's vs. 8.5's vs. 9's!!!

The next question is how much energy does each flake of powder have and what is the effect if a powder drop varies but 1 or more flakes and, if there is an effect, how do you measure it and what do you have to do to achive consistent velocities.
 

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Discussion Starter #11
I'm not trolling, it's the mix for the percentage of Antimony in shot making. My pellets normally run between 1.3 and 1.1, which is in the range for 2 to around 6% Antimony. I didn't know the formula to figure it out.

I just received some military spec lead, it measures .095 for a size 7-1/2 but weighs .8. The same as a size 9 should weigh with 2% Antimony. It's not anything I'm used to, but it's really hard and shiny.

Thanks,

Ajax
 

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Ajax,

Simple

[(Density of lead * percentage of lead (as a decimal)) + (density of antimony * percentage of antimony (as a decimal))] * volume of pellet

Make sure your units match up, and do the math inside the parenthesis first.

Skeezix did it right, I just didn't use as many significant digits.

If your 7-1/2's are weighing 0.8 grains, are you sure they aren't steel? Even a steel pellet of that size should weigh about 0.9 grains.

Check it with a magnet.
 

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Discussion Starter #13
I ran them through a Littleton shotmaker. At 650 degrees they melt and run good. Like I said it's some kind of alloy I've never come across before.


Ajax
 

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I just stepped on my scale without a pellet. Just to zero it out.

I stepped back on the scale with a pellet.

I guess it does not weigh anything.

The only thing I have figured out is I may be a tad overweight.

I hope this has helped out.

Kenny Uhlbeck
 

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Ajax,

You got me.

Whatever it is, its not very dense.
 

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Discussion Starter #16
No they're certainly not. I'm going to try some at the pattern board next week and see how they do at different yardages.

Yes Kenny, at first I did the same thing but it didn't tell me were most of the weight ratio was located :)

Ajax
 

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It cracks me up when people who obviously have nothing better to do than read these threads post to others that they must not have anything better to do.
 

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For that pellet to have a weight of 0.8 grains and be .095 diameter it would be very close to a 60% Tin 40% Antimony mix. Sounds a lot like a lead free solder mix.

lead density: 2,868 grains/in^3; tin density: 1,845 grains/in^3; antimony density: 1,690 grains/in^3

density of .095 diameter pellet that weighs 0.8 grains = 1,782 grain/in^3

john
 
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