Front Sight Pin Size? S&W 640-1

[Gideon]

Need a little help folks. I'm going to try an XS big dot on an old S&W 640-1 J frame but I'm having trouble finding the pin size and a pin. I like to have a new pin on hand before I change a sight just in case I can't use the old one.

Also, is there a direction that the front pin has to be driven out and in? Right to left or vice versa?

Thanks and if you have an XS Big Dot on your 640, I'd appreciate it if you could share your opinions. I put a Meprolight on my Ruger but I'm thinking I'd like to try the big boy on my little 640.

Thanks all and happy Friday!!
Gideon

[DefensiveCarry.com]

[ICTsnub]

I changed my 640-1 to a red fiber, pin is not tapered. I don't see any reason you can't reuse the pin other than losing it, but if need be, I can mic mine when I get home for you.

[Blue Jacket]

I can't answer the pin size question, but here's a preview of what your gun will look like with the sight change. My local gunsmith changed it and he told me he had a hell of a time removing the pin. That XS sight made a world of difference for me. Good luck.

[Gideon]

Thank you for the picture Blue Jacket. I put a Meprolight on my Ruger SP101 and like it well enough but thought I'd try the Big Dot on the shorter barreled 640 since it's dedicated to very close range SD. I had a hard time getting the roll pin out of my SP101 and the ends got deformed a bit so it turned out to be a good idea to have a new one on hand.

My finish on my 640 was a bit rough so I polished it like I just did with my Ruger. Never liked shiny guns before but I like this well enough and if I change my mind, I'll get it bead blasted.

Thanks!
Gideon