Cast bullet size ?

[lonewolf5347]

I like to ask did a slug down the bore of a 9MM
Measured Groove Diameter = 0.3567
I wonder should I stay with .357 or go to .358 in the bore?
BHN around 15 ???

[GRUMPA]

I would go the largest you think you'll need and make a dummy round. If there's a problem it'll be when you try and chamber the round and find out it's too big.

[runfiverun]

I'd go 358.
15 is okay but you could cut that down some and run a bit softer.
it is going to depend on whether your just making holes in paper, or if you want to make the holes in the paper faster.

[JWFilips]

Fat is good

[Bzcraig]

I agree.......358

[zubrato]

I usually go .002 over for 9mm, and water drop 50/50 coww:pure with enough tin for fill out.
More accurate than when I used to water drop coww.
For my .357 bore glocks I size to .359. Chambers beautifully, but requires a lee 38s&w expanding insert


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[wv109323]

Definitely .358 diameter for that bore size. Also your 9MM neck expander may not open the brass enough to allow the bullet to stay .358 when seated in the brass. Load a few dummy rounds and pull the bullet to make sure you are not swaging the bullet down when seating it. You can experience leading and tumbling if the bullet is downsized during seating.