10BNCH Mainspring

According to Bestfit, this is a sealed barrel. What you'd have to do, is remove the spring from the barrel, and directly measure it to find its dimensions. Then you can either order one that is the same, or look up the specs to see which ones are the same or similar. 

Aaron,

There is no Bulova part interchange for the 10BNCH Alloy Mainspring.

Jules Borel shows the spring as in stock and also lists a (steel) replacement as:

1.30-.09-280 8

or

GR3220

Hi Arron

Do you still need the mainspring for the 10BNCH ? I have a NOS Buloloy and would be happy to sell it to you.

John

Aaron

Where are you?? I have the mainspring you need.

John

Hey, 

I have returned. I actually found one in my stock! 

OK