Is sizing .002 over 9mm slug measured groove diameter standard?

[Bill in Ky]

I am casting COWW for my 45 acp and my 9mm. I have been told here to size my 45's .002 over micrometer measured slug diameter, is this true for 9mm's too, or for all calibers for that matter?
I am asking before I get up an order for dies.
Thanks

[tazman]

Sizing for a 9mm can be a very individual thing. Lots of different opinions because each gun reacts differently to a specific detail. Nothing is really set in stone.
That said, I would suggest you read the following link to a sticky on this site. It contains wonderful information relating to 9mm specifically.
It helped me a great deal when I started with my 9mm.
http://castboolits.gunloads.com/showthread.php?121607-Setting-up-for-boolits-in-a-new-9mm

[Buzz64]

I've found that .001 over slugged bore diameter works well and doesn't lead. Don't push magnum velocities but with accuracy in mind.

[bobthenailer]

I size all of my 9mm & 38 super cast boolets @.357 dia even if the barrels mike at 0.355 , i also get better accuracy then when sized @0.356 dia .
2 of my 9mms and 2 of my 38 supers have match barrels the rest have stock barrels.

For the 45 acp i size all cast boolets at .452 dia wheither it has a stock or match barrel.

[mdi]

Yep, rule of thumb is to start .002" over groove diameter. If wanted, you can go down to .001" over or as much as .003" over (Ive read of some shooters going to .006" over, but I haven't tried that!). As noted above, guns, especially 9mm, seem to have personalities and like a diameter ogf their own choosing...

(Meaning some will prefer .001", some will want .002" and some will even shoot best with .003". I've got 2, 9mm and one likes .001" over groove diameter and the other shoots .003" over...)

[Bill in Ky]

Ok .. I may be dumb but I ain't stupid.. This dang S&W M&P9 has FIVE grooves !!! I can't measure a slug with 5 grooves.
I will it took me two slugs before I counted LoL ..
I guess I'll order a couple sizing dies and see what happens.
Thanks for the help guys !!

[62chevy]

Ok .. I may be dumb but I ain't stupid.. This dang S&W M&P9 has FIVE grooves !!! I can't measure a slug with 5 grooves.
I will it took me two slugs before I counted LoL ..
I guess I'll order a couple sizing dies and see what happens.
Thanks for the help guys !!

The trick to measuring 5 grove barrels is .001 copper shim stock, just subtract the the difference.

[MtGun44]

Too big is no problem, too small leads badly and is inaccurate. You decide.

I size to .357 or .358 for all my 9mms.

Bill