Tapered Action Threads After Blueprinting Action

[cl5man]

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.

 

[GGaskill]

I have had problems with tapered holes in deep bored holes using HSS bits. What cures it for me has been having the side cutting edge virtually perpendicular to the work, a large end cutting edge angle and a tiny tip radius so the cutter isn't pushed away from the work nor drawn into the work. Doing this with a threading tool will be difficult.

Perhaps your problem is related to edge dullness as a dull edge will be pushed away from the work, or inadequate clearance causing the tool to be pushed away from the work.

 

[larryr]

i used to shoot benchrest and had the pleasure of meeting and sitting thru evening bull sessions with some of the best gunsmiths of the day wally and clyde hart.seely masker.ferris pendell and others. to a man they said that the threads need to be loose enough to allow the barrell to seat at the front of the action. you should be able to turn the barrel easily by hand and when it hits the action if the seat is good you should not be able to unscrew it by hand this. i usually run a tap into the action just to clean up the threads before fitting the barrel. you can also buy std and oversize piloted taps that guarantee parallel threads.if your doing this for pure pleasure and to gain experience then have at it,to accurize a remington action will cost almost as much as a custom action and you still have an old remington action.

 

[tdmidget]

i used to shoot benchrest and had the pleasure of meeting and sitting thru evening bull sessions with some of the best gunsmiths of the day wally and clyde hart.seely masker.ferris pendell and others. to a man they said that the threads need to be loose enough to allow the barrell to seat at the front of the action. you should be able to turn the barrel easily by hand and when it hits the action if the seat is good you should not be able to unscrew it by hand this. i usually run a tap into the action just to clean up the threads before fitting the barrel. you can also buy std and oversize piloted taps that guarantee parallel threads.if your doing this for pure pleasure and to gain experience then have at it,to accurize a remington action will cost almost as much as a custom action and you still have an old remington action.

Did they know how to capitalize and use the space bar? That post is painful to read and did nothing to answer the OP's question.

 

[tdmidget]

I think GGaskill may have hit it in a clearance problem. If your helix angle is not sufficient then it will cut a taper and rub. Unless you are in a high production situation you should grind your own tools and know that they work. Your insistence on indexable tooling leads me to believe that you don't have the confidence to grind your own. It only comes by doing.