SAA Clone - Barrel thread?

[Aguila Blanca]

I have a reproduction of a SAA that was made by (I believe) PIetta Arms in Italy. The barrel-cylinder gap is excessive and I an considering trying to set the barrel back one or two turns to close the gap. Somewhere in the dim recesses of antiquity, I think I remember reading that the thread pitch on the clones is not the same as on a genuine Colt SAA.

Can anyone advise me what the thread pitch is on this thing?

 

[Old Fuff]

Pietta barrels are threaded: Metric: 18mm x 1.0mm

You won't have to rethread the barrel if you only take enough off the front shoulder to make one or two turns. That should close any gap.