Bumping up bullet diameter using a sizing die

[ndnchf]

For quite a while I've had a box of bullets that are 300gr, .512" diameter. I've been wanting to try a 300gr bullet in my Uberti .50-95 model 1876 Winchester, but I need a .515" bullet to fit my barrel. I came up with the idea of using a .515" sizing die and an arbor press to enlarge the bullet's diameter .003".

As you can see, the bullet started out .512". I placed it into the die, base down and set it in the arbor press. Using the die's plunger, I brought slight pressure to bear on the plunger, pressing down on the bullet expanding it to fill the .515" die. Then I removed the plunger and flipped the die over so the base of the bullet was up. Then I used the plunger and press to push the bullet back out, ensuring it was sized evenly. I then measured the bullets and they were at .515". Simple!

A couple notes:
1. It requires consistent pressure from the arbor press, this takes a little practice. If I were to do a lot of bullets I'd make a new plunger that was maybe .010" - .015" taller than the die when the plunger is resting on the bullet nose. That way the press would push the plunger down .010" - .015" then stop when it touched the die. This would result in an even amount of compression and for each bullet.

2. The lube holes in the die must be above the area of the driving bands, otherwise lead will be extruded out the holes.

3. The bullet is a little shorter now with a wider meplat. In the example I compressed it a bit more than needed, but later bullets were not as short. But as long as they are consistent, they should work fine.

Now I have some .515" 300gr bullets to try in my rifle. I'm sure I'm not the first person to do this, but it was a new idea to me.

[JSnover]

I hadn't thought about using a lubrisizer die. Though I think you were right to use a press for consistency, there are plenty of folks who just give them a calibrated whack.

[jsizemore]

Use your reloading press with a 7/8-14 bolt instead of a die for adjustment and a flat piece of metal on top of the ram. It should give you better control of the expansion.

[ndnchf]

Ok, here is revision 1. Using a 1/2" fine thread bolt and nut, I made a simple adjustable plunger. The nut is adjusted for about .020" bullet compression, then loctited in place. That swages the bullet out to .515" in the sizing die with very little change to the nose.

[ndnchf]

I swaged 20 more bullets today with my revised rig. It worked perfectly. The bullets came out .515" and length was within .001". It's a very simple process that can be adapted to almost any caliber.

[gunboat57]

Old thread, but I use a drill bushing instead of a lube sizer die. An 11mm bushing lets me bump .431 boolits up to .434 dia. Using a 7/16" bushing I can go up to .437 diameter. I'm doing this to find a boolit size that will work well in my Rossi R92 which has an oversized groove diameter.