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Discussion Starter · #1 ·
OK. 1 1/8 load of shot wieghs 492.2 grains. In several years of reloading I watch my powder drop wieghts religiously but also knew my shot drop was light. Decided to fix this. Opened up the shot bushing to get drops of 482 to 488 grains (this is with West Coast Magmum). Now running Lawrence magnum and wieghts went to 507 to 512 grains in the same bushing. Is this a product of antimony or shot diameter? Also have several bags of Black Diamond and will test them. What's up.
 

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And now the homework assignment. Is there a way to decide which of the above is mostly right? Or are they about equally likely? Show your work.

Neil

For extra credit, is there a way, short of metallurgical analysis, to know almost for sure?
 

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Count the number of pellets in each drop. If the number of pellets is the same then it's the alloy. If I was a betting man I'd say Lawrence has little or no antimony in its shot. HMB
 

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The bushing is not a scale. As such it delivers shot by volume not weight. Consequently, the density of the shot is far less material than the size of the shot.
 

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To save looking it up, antimony has a density of about 6.7 gm/cc and lead about 11 gm/cc. Guessing that West Coast has 6% antimony, is it possible that it's _all_ an antimony difference that accounts for the beast's findings??

Show your work.

Neil
 

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You deal with it by invoking the ATA rule which allows you a 3% overage and boning up on the idea of significant figures. You are home free.

Neil
 

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I have tuned my reloading bars by honing out the shot hole a little at a time and then droping a few loads though the reloader until I got a pretty consistant weight of 492 grains of #7 1/2mag shot. I did this to three different bars honing each bar for a specific shot size, one for #7 1/2's, one for #8's, and one for #8 1/2's. I made sure that I marked the bars for each shot size, as it made a difference in the drop weight if I used the smaller sizes in the bigger bar. I am now droping my shot load by weight and not by volume and I have noticed that if I go to chilled shot it does make a difference in the weight due to the antimony that is added. Dusty
 

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Hello,

I did something very similar to what you did. I fixed my over sized bushing by adding pieces of masking tape to the inside of the bushing. It takes a little time to get it right because you have to add the tape, reinsert back into the bar, fill the shot tube, drop a few test loads, rinse and repeat...
Or you could just by a Universal charge bar. I installed one on my 9000G and it works like a charm. Best money I've spent in a long time! If the loads are a little off, it's a piece of cake to adjust up or down.

hope this helps,
Randy
 

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Density of 6% antimony shot is 11 grams/cc*.94+6.7 grams/cc*.06 = 10.74 grams per cc which is a difference of 11-10.74 = .26 grams per cc which is .26/11 = .023 or 2.3 percent lighter than pure lead.

25 grains per bushing difference is about 5 percent of 482, so no it can't be just the antimony. Neil's right.
 

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Discussion Starter · #19 ·
Just loaded several shells with Black Diamond magnum shot. Drops weighed from 492-498 grains putting it between West Coast and Lawrence shot in drop weight.
 

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Pour the shot of each type in a graduated beaker half filled with water. Measure the displacement of the water. The one with the lowest displacement will be closer to pure lead; the one with the highest displacement will have more antimony. In this test, the size of the shot is irrelevant.
 
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