Weight Variance with 358429 Mold

[ColColt]

Last week I cast up several hundred from the 358429 mold using Lead/Linotype which gives a BHN 15.4 alloy. The boolits weighed on average 158.2 gr. Yesterday, I did the same with the same mold but used WW's plus 3.5 ounces of tin which yielded a BHN11 alloy and weighed on average 165 gr.

Knowing a harder alloy will give a larger but lighter bullet I didn't think it would weigh that much less than the 170 gr it should have been normally. I figured with WW's and tin it would weigh a bit more than 170 gr but got a surprise there as well. Lyman uses a mix of Linotype or Lyman #2 to standardize weights for a given boolit but mine seem to be off a bit. Twelve grains less on the harder boolit seemed too much and could probably use 158 gr boolit reloading data with this weight instead of 170 gr data. The WW's with tin I figured should have been about 175 gr. Has anyone else experienced this? The WW ingots averaged BHN9.4. Alloy temp was kept at 630-660 degrees.

[Larry Gibson]

That's not too much varience for those two alloys. The WW alloy has a much larger amount of lead in it. The larger a bullet that is cast the greater the weight disparity will be.

Larry Gibson

[fecmech]

That might be an example of Lymans famous mold consistency. I have a 4 cav 358429 from 1970 with a round grease groove. It casts Straight ww's at about 173 grs, ww's +2% sn about 171-172 and straight lino at 163 grs. Sounds like you 358429 is slightly smaller than my 358429.

[ColColt]

That's about the weights I was expecting with ww's-especially since they checked out as BHN 9.4 but I did add a bit of tin. This mold was sent back to Lyman due to undersized problems such as the front band being .356" and now it's .358 with the center and base band .359 prior to sizing. WW's should have been at least 170 gr I would have thought.

[cbrick]

You didn't give the percentages of alloys you blended but I agree with Larry, that's not all that much variation for an alloy change. He's also correct in that the larger the bullet the more variation there is. Cast a 500 Gr. 45-70 bullet and then change the alloy and you'll see some real variation.

Rick

[ColColt]

One of the two alloys was 50/50 Lead and Linotype and the other was ww's plus 3.5 ounces of tin(10# lead to 3.5 oz tin). Both were for the 358421 mold. As I stated, I expected the ww mix with tin to be 170+ gr but it wasn't. I figured the lead and lino alloy would be lighter but not 5-6 grs lighter for that mold. If Lyman used a #2 alloy to design that mold my 50/50 should have been about 170, give or take a couple grains and the ww's with tin I figured would be about 172-175 gr havinig more lead content. It's not all that important but, I was curious about the weight differential.

[durant7]

I am going to piggyback on this topic as I am experiencing something similar I believe. First, I am a rookie caster. my 429215 Lyman mould is only my second after a 31146 for my 30-30 lever gun.

I collect lead from where ever I can get it and understand the alloy issue but don't manage it per se. I know which 16 oz ingots have some Lyno in it and which ones are pure lead from suba belts. You can see it in the color. I attempt to feed a small 10 lb pot from Lee. The smallest bottom pour they make. But, when you have 16oz increments you can't really manage the ratio easily.

So....I weigh my bullets. 215g to 223g. Much bigger spread than my 31146 bullets which makes sense because of the heavier bullet. Harder bullets are 215g, softer, more pure lead bullets are 223.

So, I chucked everything below 215 and above 223 into the pot and remelted them. Viola, I got 219/220 g bullets all night long.

My question. Does a 8 g spread matter? For a brief moment I looked at the 500 bullets that make up 215 and 223 and considered remelting them to have more 219 bullets. What a huge time burner. There comes a time when.....

My use, NRA CLA Silhouette competition.

Have I diagnosed my issue correctly? Since I don't have a "large pot" to mix all of it together I am kinda stuck with my problem. Or am I making a rookie mistake? Does 8 g matter? Would you chuck 500 bullets back in the pot to get a "tighter" spread of bullet weights by having a "tighter" alloy spec?

Thanks,

The rookie in NH.

[kelbro]

8gr is almost 4% and it will make some difference. How much is hard to tell.

[ColColt]

I segregate mine by weight as well but consign those out of the realm of being more/less than my average and lump them together and shoot them except I don't mix them with the others. I seldom dump many back in the pot. In y our case, a 2-2.5 gr difference wouldn't hurt a thing accuracy wise but five grain difference, yep, I'd segregate those with others of like weight. In other words, those that were 219-221 I'd have no problem shooting them. Others that were say, 222-224 or so I'd shoot those together. If you're pinking it don't matter. This is for target accuracy separation. At least, that's the way I do it. A 1-1.5% difference wouldn't matter.