Not new to blueprinting actions. My process until recently was using carbide threading tool inserts and chasing the action threads by rotating the chuck manually. This method is comfortable and works great for me accept for the occasional insert chipping when I don't stop the threading tool in the gas port on the side of the action at the end of the thread. So I decided to buy a pre-made HSS internal threading tool. It cuts much smoother than the carbide but the first two actions that I used the new tool on ended up with tapered threads. One much worse than the other one. Unfortunately I didn't catch the taper until I was threading the new barrel for the build. Very sloppy threads and they don't snug up till the last few turns. I'm afraid the action is a write off for this build. I'm assuming my problem is flex on the new HSS threading tool. Its a fairly small tool, 3/8 shank with plenty of clearance ground out for depth. Im taking .001 at a time, how beefy does it need to be!! My old carbide setup from Dorian always gave me nice straight threads. Anybody got an ideas why the HSS tool isnt cutting as good? Id really like to find some HSS inserts that will fit my 11IR-A60 tool holder. I've searched for hours and cant find anything. I really don't want to get into HSS tooling unless its indexable. This one pre-ground HSS internal tool was going to be my only exception.