Finally shot my new '51 Navy

[AtlLaw]

This is the Uberti I finally bought in lieu of the '62 Police after I had to return 2 of the latter pistols to the supplier.  Anyway, the Navy shot as well as one would expect from a Uberti, and I was very satisfied.   
 
Hi-ebber, and day always be a hi-ebber,  several times the rammer lifted the balls out of the chamber after seating them on the powder.  And once I had a ball back out of the chamber from recoil!     To me this meant the balls were undersized or the chambers were oversized.     Since I use the same .36 cal balls, cast from a Lee .380 mould, in my '61 Navy and they work fine, I suspected the latter.     Another indication was that I noticed very little lead rings being shaved off when seating the balls.
 
So I did some measuring last night.  As close as I can tell with calipers, the chambers all measure .370.  Which to me means they will go a hair over that in diameter.  The balls measured .373 - .375.  Come to think on it, I should have measured my '61's chambers for comparison... oh well... 
 
I would bet that the balls on the high side of the measurement range were the ones that stayed seated, while the ones on the low side were just too loose a fit.  Can anyone think of another reason?
 
I think I'm going to polish the mould cavities and try to open them up a bit so the balls all drop at .375+.  That is unless anyone has any other ideas!   

[Fingers McGee]

Hey AtlLaw, sounds like mold isn't throwing .380s.  The cast balls I'm buying now mic out at .378 to .381 and work perfectly in my Navies and Police revolvers.  Store bought Hornady .375s will work in my Pietas; but, are loose in my Ubertis. 
 
I bought a couple thou cast balls last year that were supposed to be .380s.  When the first one rolled out the end of one of my '61 Navies - during a match -  I quit using that package & when I got home, I mic'd some of the batch and found that they ranged from .371 to .379.  Not one I checked mic'd over .380.  Unfortunately, it'll be impossible to get them replaced or my money back.  The guy I got them from has been very unresponsive to both me and a slew of other customers.  I'll just have to save them for my Piettas.  Chambers are tighter in them.

[fistmil]

I have a Uberti London model Navy and the paper work that came with it over 30 years ago recommends using a .380 ball. I purchased a .380 round ball Lyman mold and for the past 30 years they both still work well together. There is a reason Lyman molds cost more than Lee molds.

[AtlLaw]

Hey Atlaw, sounds like mold isn't throwing .380s.

It sure ain't!  most of the balls I measured are around .373 with very, very few reaching .375.     I'm going to polish out the cavities of the mould and see if I can open them up.
 

I purchased a .380 round ball Lyman mold and for the past 30 years they both still work well together. There is a reason Lyman molds cost more than Lee molds.

I 'spose you're right, though I've been mostly satisfied with the Lee moulds I have.  Not star struck mind you, but satisfied.     Hi-ebber, and day always be a hi-ebber, .007 undersized is a lot!
 
I hope I can open the mould up to throw balls that measure close to .380.  If not I'll have to get a new mould.