IIRC from the other Double Extractor threads, Many (if not most) are doing okay using the factory screw if they're just
Doubling Up the extractor springs. There were a few early on that went as far as
Tripling Up the extractor that found the factory screw was not long enough and needed to get a longer screw (and having to grind it down because it was obviously too long).
As FF2 wrote... You should be able to tell as soon as you double up the springs whether the screw is long enough to hold the firing pin in or not. [Shrug]
If in doubt, take the factory screw to Lowes/Home Depot/Ace Hardware, find the next longer screw with a matching thread and see how it goes.
