How are these weight variances?

[tarbe]

Cast up about 150 300gr 45 Lee from a two cavity mould...75% WW/25% Lino.

Most of the boolits were 301.5 to 302.5. Had a portion (15%) that were a little lighter...300 to 300.5. Had three heavyweights between 304 and 305 :roll:

I think the lighter boolits are from when we let the melt get a little high and/or casted a little too fast (some frosting). I tried to keep the melt at 750, but I know it crept up to 800 at least for a little while.

No idea what caused the heavyweights.

I will load the lighter boolits all together and shoot them separate...but this is not a match gun or load...just a plinker (45LC).

I guess what I am asking is...are these variations within what you would call normal, or am I in need of some remedial quality control? :mrgreen:

thanks,

Tim

[Leftoverdj]

You're within +/- 1% of the median. Since you have already weighed them, might as well throw back the three heavies, but you'd get no visible difference if you shot them all.

[mooman76]

Like Leftoverdj said it. That's pretty close. You are not going to get exact and you'll drive yourself nuts trying to. Lead is very heavy so it doesn't take much to be of a hair. Fluctuation in temp, alloy slight difference in the mix or whatever.

[454PB]

You're doing great, and you're gonna love that boolit!

[Bret4207]

Take a look at the lighter ones. You'll probably find some less than filled spots or maybe a slight depression in the base. That's all it takes.

I find casting fast so the mould gets nice and hot gives me better fill out. If the boolits are frosted, so much the better. Mould temp is controlled more by casting speed than alloy temp IMO.

[sqlbullet]

My 'heavies' almost always are the result of my mold not being quite closed. I bet if you mic them you will find them to be .001-.002 or so out of round.

[tarbe]

Thanks for the feedback guys. Sounds like I am in the ballpark.

The "mold not closed all the way" explanation for the heavies may well be right on. We did have a couple with fins toward the end of our session that had to go back in the pot. Had a piece of crud on the mold face. Those heavies may have snuck through...not visibly finned but a little off nonetheless.

thanks again all,


Tim

[44man]

Boolit weight can vary with a change in mold temperature too. If your casting is good so you do not get voids, ignore small differences. I never bother to weigh boolits anymore because even sorted very close, I never seen any difference at the target.
Shooting BR or small caliber boolits would make me weigh them I suppose.
My friends and I are shooting what might be the smallest revolver groups that have ever been shot with cast boolits. There are a few others here that do it too. None of my boolits pass over a scale.
Once the casting process if refined and you keep the blocks free of splatter, keep the handles closed tight and get perfect fill out, you can ignore the scale.

[tarbe]

Once the casting process if refined...


Exactly....

A few more sessions with decent results and I believe I will be able to reserve the scale for setting my powder measure!


Tim