Drill & Tap PTA for 8-40 Screws?

[pgcpty]

Hi Y'all,

Anybody actually drilled out the 6-48 scope mount action holes in a PTA to re thread to 8-40?

How hard is the stainless steel?

I've done this on other actions by setting the job up in my mill and using it as a jigbore to drill out the holes then put the tap in a mill collet chuck and hand feed the tap in to and fro small increments with lubrication to prevent breaking the tap.

A lot depends on how hard these actions are

Experienced comments appreciated

Thanks

Peter :D

[sinman]

SS cuts nicely

[pgcpty]

Should I draw from your reply that the SS hardness of the PTA is significantly less than say 316 which is hard work on taps?

[sinman]

I have never tapped a savage action but with a quality tap and fluid it should be easy