I understand what you're saying Semi, but as a machinist, if I had a dimension that was 11 mm on a print, I converted it to inch and machined it accordingly. We would usually leave .006-.008 on an O.D. and .004-.006 on an I.D. leaving grind stock after hardening processes unless it was a "hard turn" which we were usually given plus or minus .0003 - .0005 depending...

I would machine an 11 mm dimension to .440 O.D. and .438 I.D. for pre-harden spec and .4332 - .4328 as hard turn with those given tolerances.

BPS

Blackpowdersmoke, No I am not figuring in the paper. I am not saying that their 11mm name is the correct measurement. I am just calling it what they call it.
RCBS sells this mould as a 11mm but the bullet falls out with soft lead at .446
They also say that it is a 370 gr mould. The standard lead that is used for this is #2 Lyman mix that is actually hard, 15 BHN hard to be a little closer to exact. So when I pour these with 8 BHN hard softer lead the bullets come out at 409 grains but they are still .446 diameter.
With paper these bullets are in the .451 range with my paper. I size them to .446 for this rifle. The paper will puff out a bit after sizing so they slip easily down the bore but they don't fall out if tipped down. If i had a sizer die that was .448 I would probably use it so it was a pinch tighter but I like the way these shoot as I have them. This is the info on the mould.

http://www.midwayusa.com/product/695...ProductFinding

That's interesting Ron...

Probably because the softer lead mix you pour is denser (less porosity) than the 15 BHN mix which accounts for the additional weight while still maintaining size.

However, I still think it kind of odd that a manufacturer of quality conical moulds would list the size as 11 mm with it being .013 oversize but then again you can buy round ball moulds that significantly vary from the size that they're listed as...

.36 caliber as .351 or .375 (somewhat of a size spread there, Eh?)

BPS