Cant find one so trying to make one. Need advice.
Using 1095 blue steel. .023 thick ..069 wide.
Process so far is..

1. Anneal
2. shape
3. harden = Cherry red magnet drop (tried water and sae30)
4.Temper= Lee lead pot 650-700 count of 15 sec.

I think there's away around the external side of the bolt stop altogether: http://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/927108139/xsl/print_topic

I've never seen a 1640 action up close so not familiar with exactly how it looks.

You still need the spring.

Yes. The spring is the thing. You must have at least 1. I have two made and 1 installed..working for now. I have tried 3 local smiths. All declined the work. One smith a few hundred miles away will with a 4 month wait..

http://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/927108139/xsl/print_topic
Whatever happened to TC1?

I have made piano wire springs for this and they worked ok. This spring is the actions weak point. GD