Neck expanding

When we reload, the brass is "sprung" in that it had to expand to release the bullet that we last fired. This makes the cartridge slightly oversize, and before we reload the bullet we have to bring that dimension down to properly hold the bullet.

Full length resizing or neck sizing takes care of this little problem. The neck of the brass is brought back, generally, to 1/1000th (one one thousandth) of an inch smaller than the bullet we intend to load. In a common .30 caliber cartridge that seats a .308 bullet, the neck will be sized to .307. Loading the bullet will provide the tension needed to hold the bullet in place, unless we intend to crimp it for use in lever action or pump action weapons.

We're not talking about crimping today, though. That is a whole nuther problem that we will deal with in the future.

When we reload a cast bullet, that sizing we did earlier makes our job harder. Almost impossible. A cast bullet is softer than the cartridge brass and the bullet won't size the case neck. The case neck will shave lead off one side of the bullet, rendering our carefully cast and sorted bullet unstable. An unstable bullet flies God-knows-where, which is not conducive to accuracy.

So, we must flare that case neck. We make a funnel of it, wider at the mouth than necessary to give our cast bullet a chance to start into the neck without shaving lead. Some folks just use a screwdriver tip to expand the brass. This is certainly a useful skill, but Lyman makes something called an M-Die that is found in popular calibers and is designed just for this task. Lee also makes a die, a universal neck expansion die.

Remember, in flaring the case neck, go easy. Only induce enough expansion to start the bullet by hand. Too much expansion doesn't help the bullet, and work-hardens the brass. Just enough expansion is what we are looking for.

Last year, I ordered the Lee die and I am very happy with it. It comes with two expanders that will expand brass from .22 caliber up past .45 caliber. The die and expanders are constructed so that you can set it up to resize the shortest brass or the longest brass.



The simple instructions come with the die and by using one or both of the expander buttons in one of several configurations, we are able to simply expand the case neck just enough to hand-start the bullet in the case neck before we seat it.



This photo shows a cast bullet started in the mouth of a .30-30 case. The expanded portion is barely visible in the picture. As this bullet is seated, the seating die will "iron" out the flare, and the cartridge will be ready for crimping.

If you don't have an expanding die, or are looking for one prior to using cast bullets, I recommend the Lee Die. It has served me well since I got it.