So I've been working on my old KT frame and have a STI beavertail. How can I tell if the KT frame will work with the STI? Any tips or tricks out there?
You could try installing it... :) There are two kinds of beavertail frame cuts that I know of... There is the Wilson type that is a compound radius, and a little more work to insatall, and then there is everyone else's cut which is a standard radius (.250" I believe) I believe that STI uses the .250... You can check out Blindhogg's site for a quick description of both types... http://www.blindhogg.com/gunsmith/beavertails.html
If your frame has had the tangs cut, I am sure it is for the .250. Probably would still need some fitting though... There are some cheap jigs you can get at Brownells to help with the install...
EDIT: Looking at the KT website, it looks like the frames come with uncut tangs... You will need to do some cutting to get anything but a Wilson "drop in" to work...
I think you've got a lathe. Take a piece of 5/8" round stock (drill rod would be best), and turn a spigot that will fit into the hole in your beavertail (where the thumb safety goes through). Now turn the larger diameter so the spigot can go through the pin hole and the outside diameter is snug/flush against the clearance cuts around the hole. (Hopefully this will make sense when you start trying to put the spigot into your beavertail pivot hole).
When it fits, cut it off and face the cut side. Now make another. What you have are two 'buttons' that you can now install in the frame and use as file guides to file down your tang - just file and sand until the tang is flush with the buttons and your beavertail should go on with little or no further fitting. If you made the buttons from drill rod you can harden them before use which will help protect you from digging into them while filing.
You should deffinately go check out Blindhogg's site... If you are starting from scratch, you can still choose which type to use... Some swear by the .250 radius, and some (like me) prefer the Wilson cut... I believe it allows for a tighter gap than the straight radius...
Hey Zen, I have a the Ed Brown for the .250 radius cut. That is what the STI takes. I looked it up on Brownells. You can borrow the jig if you want. I can mail it to you to use and then you can send it back when you're done. Just let me know.