Sizing/gas checking right after casting?

[hc18flyer]

My last set of 358win bullets were sized right after casting. Recently I read a post that said you should allow 30 days to time harden, before sizing. I have been air cooling. Is there consensus on the best way? Does water quenching get treated differently? Thanks, Flyer

[Tatume]

Hi Flyer (that sounds cool),

If you size right after casting your bullets will not "spring back" quite as much, and may be a few "tenths" smaller. It usually won't make any difference whatsoever. You probably won't be able measure the difference, and very probably won't see any difference on target. Find out for yourself. Size 20 right after casting, set 20 aside for a month and then size them. Go to the range and carefully shoot two 20-shot groups at 100 yards. Measure the groups and compare. I'll bet there is no difference.

Take care, Tom

[Foto Joe]

You don't say what alloy you're using but let's assume COWW's. If you water quench your initial hardness will be greater than air cooled and in my experience will harden another 20-30% within one to two weeks into the low 20's bhn. Whereas air cooled COWW's will wind up around 12 bhn.

Here's the issue though, you're gas checking. I formerly water dropped for my 30-30 boolits which are being pushed to just below 2,000 fps. Since I gas check these I quit water dropping alll together since the gas check negates the need for a hardness of 21-22 bhn. As far as I'm concerned water dropping is an extra step which you don't need when gas checking boolits, some may disagree.

[Wayne Smith]

To specifically answer your question if you are air cooling no, it really doesn't matter. For me it is a practical issue, when I water drop it is way easier to size immediately than to wait until they have hardned! I gc and size the same day I cast and water drop.

[1Shirt]

Agree with Wayne. I water drop everything as a matter of convenience, and try to check, size, lube the same day,or the next day for sure.
1Shirt!

[tazman]

I agree with Wayne and 1shirt.
I water drop and if I wait a few days, sizing can be very tough. Much easier to size right after casting. I usually cast first thing in the morning leaving me time to finish the boolit preparation.
I once cast up a bunch from linotype and waited a few days. I ended up melting them back down and recasting them they were so difficult to size.

[Foto Joe]

I'm going to ad a little caveat to water dropping here, there's nothing wrong with doing it and many do but... If you weigh your boolits for uniformity and remelt those that are out of speck for whatever reason i.e. improper fillout, rounded base or most importantly voids, the latter can get you a visit from the tinsel fairy during remelt.

[Shuz]

I've read articles written by metallurgists, that claim if you size your boolits after quench casting or oven heat treating, you negate some of the benefit of getting a harder boolit, because the sides of the boolit that come into contact with the sizing die, get work softened. These are the same sides, obviously, that come into contact with the rifling. Therefore, to eliminate this problem, I size and then heat treat and lube and gas check.