45 ACP lead bullets expanding the case?

[leam]

I'm reloading 45 ACP with lead bullets (Valiant and/or local manufacture). Often after loading the outside of the brass looks like it has expanded slightly where the base of the bullet is. So far I've had no feeding issues or anything else, but I'd like to deal with this before I do. Measuring the case at the bottom is .468, at the first part of the bluge is .470, and at the mouth of the case is .472.

Suggestions?

Leam

[ChrisStock]

.469 at base, .470 at base of bulge, .469 1/2 at case mouth with my cast lead. I have created 8 shot cloverleafs off of the bench at 20 yards with that load and my SA 1911. If it's not broke, I'm not fixing it.

[Yankee Dog]

I have never measured mine. But there has always been a line visable at the bottom of the bullet. Never seemed to affect anything so I never worried about it.

Yankee Dog

[Flexmoney]

Each wall of your brass is about 0.010 (and you have two walls in the measurement).

Your bullet is probably about 0.451

0.451 + 0.010 + 0.010 = 0.471

What you are seeing is likely what is referred to as the "coke-bottle" effect. Before putting the bullet on the case while reloading, the brass is re-sized. In this instance, it would seem that your brass is re-sized to a diameter that is smaller than what it would be with the bullet in the case. (you can check this be measuring the diameter of the brass just after re-sizing)

The other way to get there is by using a Lee Factory Crimp Die (FCD). This die will size the round after the bullet has been seated in it. One idea behind the FCD is that is snugs the case wall to the sides of the bullet. Gripping the bullet snugly...Sizing the whole round. **Some caution doing this with lead bullets, as they feel that the lead bullet will squeeze down in size, but the brass may spring back a bit...giving the opposite result...a not so snug fit of brass wall to bullet.

Your measurements sound fine, I think (somebody want to check me on that...as I don't load 45 much).

[Franklin D Wolverton]

Mine do the same thing. Same response as everyone else... they feed and extract fine, and they hit where I aim them.

Frank