I was given 500+ hand cast .38 swc bullets from a friend who got them from a friend. I was told they were all 158 grain.....well nothing is free...they weigh in from 155 to 167 gains. I am a intermediate skilled reloaded, I usually stick to data/bullets I know and trust. I have data for the 158 BUT the other weights are in question. Does anyone have data for the higher weight bullets?.

That's a huge variation if they came from the same mold, unless they were cast from different alloys.

no idea on mold and/or alloys. I know the deviation is too extreme for a single charge. the high and low weighted bullets are going to be tossed, not enough to warrant a special run on either end.

Speaking of deviation, what is everyone's standard deviation? since I don't make my own bullets, I would think +/- 1-2 grains if being used for plinkers..

That is a big deviation, from a percentage of the total weight, not really as big as it sounds. Certainly a powder charge deviation that much would be HUGE and dangerous, but plinking bullets, you might not even notice the difference.

that's about 6%.
I usually hold about 1grain difference in my casting.
but I toss the first bunch back and keep the mold at a consistent temp when casting.
you could do a run and lay out the bullets from front to back and weigh out a bell curve.
the pot going down, temperature fluctuations as it cycles off and on, and the first ones from the session in a non heat soaked mold, will make up the low end weight groups.

avoiding those three factors alone will tighten up a casting sessions weight variations immensely.

will you notice a few grains of weight when shooting?
I doubt it, just as 3 bhn won't make a big difference, unless your on the ragged edge to begin with.

if you load them all in 357mag cases at a high "38spl" level with say 5.5grains of Unique you should be have somathung useable and safe...



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