Bullet springback

[JRLesan]

Long story short: can water quenched clip on ww spring back after going thru a sizing die??? Mine apparently do to the tune of .002 in a 454 sizer. Drop out of the mold at .456.5 and come out of the sizer at .455.5 or thereabouts. Measuring the inside of sizer shows .454 and couple of tenths out of round and a slight taper increasing towards the bottom of the die. Bullets out of the mold show a slight out of round and once thru the sizer look like their being trued; ie not contacting completely all the way around. Multiple trips thru the sizer with the bullet being reoriented does not change dimensions or rub marks from the original pass thru.

[Don Purcell]

They most definitely will as I have had it happen many times. A 315 grain Keith in .45 caliber out of the mold at .455 sized in a .452 die comes out at .453. A .432 bullet thru a .430 die comes out at .431 for me.

[country gent]

Lead and its allots are pretty dead materials as far as spring is concerned ( we used lead wire or solders in a pinch to measure dies clerances. set a piece in cycle press and measure the smashed lead wire) and may nott be all the issue your seeing. The thin wall of the sizer die with the harder alloy may be opening expanding some under pressure of sizing the harder bullet. From your numbers above 456.5 bullet comes out .4555 inside of the sizer .4542-3 your talking just over .001 variance.
The other thing to try if possible is borrow or have a person size some of your bullets in another .454 die and see what they come out compared to that dies size. If they stay the same over the new dies size then its your alloy if not it may be the die body. Another is while it dosnt happen very often look over the body inside and out for cracks. This may be causing the size variance your seeing.

[popper]

Pb doesn't but the Sb & Sn provide the different results through the same sizer die. Answer is YES.