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209jones
09-25-2011, 04:46 PM
So, Built some 320gr LBT WFN-GC's, wheelweights, water quenched. Came out at .413. Sized them to .412. Discovered they would not clear the crimp ring in my Hornady seating die. Tried .411, same issue, shaving. Then went .410, no problem.
In the course of this I also tried some .411 sized, wouldn't chamber if seated to the crimp groove.
So, as I was experimenting on reject boolits, i grabbed 20 good ones that were sized .412, flipped them over and sized the noses to .410 to the crimp groove.
Seated great and chambered no problem. Checked each and every one.
Get out to the range today, wouldn't chamber. Gave them a shove, shot them.
Basically pushed them into the lands, a hair more than the thickness of the rim.
Semi-breechseated them. (450-400NE) Shot just fine. Was doing workup on AA5744, very happy with it, 48gr got me to 1975- 2000fps.
I had a few that I couldn't push hard enough on to get them in. So, when I got home, measured them, back to .412.
So, two possibilities occurred to me to cause this growth, over 4 days since sizing them. It could be springback in the material, I can't see it being ambient temp doing it, not that big of a change in the last few days. The other is storage, and travelling down a washboard road with 'em standing on their noses in the MTM box.
So, .002 springback? or, weight of the cartridge enough to do it on a washboard road?

PacMan
09-25-2011, 07:59 PM
Just a guess here. Sizing down only the nose on that size bullet maybe just to close to the bullet shaft and spring back was more than normal by not actually letting the die lengthen the bullet. Maybe an AC would have acted diffrently. You always get more spring back with a harder bullet. I have nose sized LBT 359 180gr before and gennerally had little spring back.
Maybe and i said maybe you could run them in a little deeper and they would be more likely to stablize.

243winxb
09-26-2011, 09:35 AM
Q: I have run my bullets through the sizing die, however they do not come out at the expected diameter. These were cast in wheelweights, would that make a difference?
A: Yes, bullets cast in pure lead or wheelweights will come out smaller, bullets cast in linotype will come out larger. This is due to the spring-back of the bullets being sized. The sizing dies are made to produce the diameters using #2 alloy. http://www.lymanproducts.com/lyman/faqs/bullet-casting.php :smile: