Lee Bullet Sizing Die problems.

[Colorado4wheel]

Is it common for Lee sizing dies to be undersized. I ordered a .356 and it was sizing at .354. So next time I ordered a .356,.357,.358. This time the .356 was sizing to .3555, and the .357 sized to .356. The same bullets sized in my buddies star at .356. Is this typical Lee sizing issues or are my bullets some odd material.

[randyrat]

Be sure your measuring equipment is accurate first, then send it back or open it up a bit using a slit dowl and 400 grit sandpaper then smooth it a bit with 600

[Colorado4wheel]

I double checked it at my friends house.

[buck1]

Easy to open up a bit.

[MyLeadHabit]

My new .356 pops out .355 boolits every time. Send it back? Open it up? Buy another one? I'm not sure just yet. I know my calip is right on.

[Buckshot]

..............Alloy changes will cause boolits to exit the dies over or under what's stamped on them. The larger the boolit, and the closer the alloy is to either end of the common alloy spectrum (pure lead or linotype) will have the greatest effect. Also if you're using dial calipers most will resolve to a half a thousandth (.0005") but that doesn't mean they'll repeat to a half a thousandth.

Mould block material in conjunction with alloy and casting temp can all add up to the loss or gain of fractions of a thousandth also. Also boolits cast today and sized day after tomorrow will size smaller then boolits cast 3 months ago assuming the same alloy.

Does that mean the manufacturer is always right on with the size stamped on the die? Nope, and bad ones do get shipped. If you have common WW type alloy and it comes out of the die MORE or LESS then a half thousandth off the number stamped on the die, then the die is probably faulty. If I had a die sizing a half a thousandth OVER I wouldn't be worried about it as I doubt anyone is loading anything to the degree that a half a thousandth would be of any real concern. Undersize generally will casue more problems (leading/accuracy) then oversized by that much.

If it's a Lee push through they're fairly easy to open up as the actual area doing the sizing is only about 1/10" wide. Not much material to be removed.

................Buckshot