Boolit weight variations

[awaveritt]

Tonight I got a wild hair and decided to weigh some of the 400 boolits I cast this week and discovered that (out of 25 or so boolits) 60-70% of them weighed 125 grains and the others weighed 124 grains; All of this out of a Lee double cavity TL-356-124-2R. So that got me thinking of a couple of questions: Could one cavity be dropping the one weight and the other dropping the different weight? Also, I weighed these after applying the LLA so would that skew my weighing them. Also, what kind of variance do you all see among your multiple cavity moulds, as it seems to me that a six-cavity would really be even more prone to this.

OK, I'm editing to share some additional observations: I can tell which cavity the bullet came from because of the location of the sprue mark on the bullet base. One is off center and these boolits weigh 124 grains and are slightly out of round when measured with a caliper - .356 - .357 - .358. The other cavity produces a 125 grain boolit and is consistently round and measures .357. So. . . . is this all that out of the ordinary or is this enough difference to quibble over. I'm going to the range later this week for my first testing of the boolits in 9mm and .38 snubby. Meanwhile, interested in your observations on this. Thanks.

[vincewarde]

One grain is not a lot of variation - most standard quality jacketed bullets will vary at least that much.

[BruceB]

I agree with Vince....it's not enough variation to worry about.

One of my .270 moulds is the RCBS 270-130, 2-cavity. The two cavities cast bullets which are almost precisely one grain different in WW alloy. I marked one cavity by filing a miniscule notch dead-center on the meplat, and one of my "someday" projects is to try bullets from each cavity (segregated) for grouping, as well as a series of groups with mixed bullets from both cavities. I'm pretty certain that there won't be any noticeable difference in the grouping ability.

As a rule, I'll accept greater variation in handgun bullets, anyway, because for *my* type of handgunning, great precision is not necessary. Back in my Bullseye competition days, it was different....

[qajaq59]

One of my older Lyman .308 molds is off by about that amount from one cavity to the other, but it doesn't seem to show up in the shooting accuracy. However I know some guys will take a punch and make a mark on one cavity so they can tell them apart at a glance.

[randyrat]

Thats great! less than 1% variation. If you were making precision rifle cast boolits you would want to stick with one cavity. For pitol, not worth the slower production.

[XWrench3]

If you were shooting 500 yards plus with a rifle, i might get worried about a 1 grain difference. But with a pistol, 50 yards is a long shot for most of us. I would not worry about it.