Truing Remington 700 Action Threads

[fishingreg]

Hello,

Another question for the group that I have not been able to find a simple answer for online, (and maybe there is not a simple answer)... Once I true up the action threads on a Remington 700 action, I of course understand they are slightly oversized. The issue I have is, from there I do not know what my major size should be when I turn the tenon on the barrel. Is there some math to this? I have cut plenty of threads and of course understand to make a custom match for the barrel and tenon once I know the major diameter for the tenon but how do I determine that major diameter once I have oversized the action threads? This is probably a really stupid question for someone with experience but for me, I can't find a straight answer anywhere on how to measure for that.

Thanks,
Greg

 

[300sniper]

Make go/no-go plug gauges to the specs you want the threads to be, then use them as you are opening up the receiver threads.

 

[Jim Kobe]

Just make an undercut at the front with the threading tool after the last pass and measure that.

 

[GenePoole]

Get some full-profile inserts and some thread wires (or thread mic) and make your own thread gauges. A great way to practice threading.

 

[RWO]

A simple way to measure the receiver threads is to plug the receiver ring 1/2" or so down with a piece of cardboard or tape and pour a layer of Cerrosafe on the plug a few threads thick. A hexhead bolt standing head down on the plug will give a handle to unscrew the casting. As soon as it cools, unscrew the casting. 30 min. later it will be exactly the thread size and shape Measure it.

RWO

 

[fishingreg]

A simple way to measure the receiver threads is to plug the receiver ring 1/2" or so down with a piece of cardboard or tape and pour a layer of Cerrosafe on the plug a few threads thick. A hexhead bolt standing head down on the plug will give a handle to unscrew the casting. As soon as it cools, unscrew the casting. 30 min. later it will be exactly the thread size and shape Measure it.

RWO

Thank you, that sounds like a really good method. I worded the question to be as if I were opening up the threads which in this case I intend to but I was also thinking what if I needed to make a tenon for an action that might have already been opened up, how would I determine the major for the tenon. This sounds like a great idea and I will for sure be testing this.

Thanks,
Greg

 

[fishingreg]

Just make an undercut at the front with the threading tool after the last pass and measure that.

Thanks,

I can see how that would work pretty good. I assume you would make your major a couple thousands under the size of the undercut?

Greg

 

[Jim Kobe]

Yes, about .005" less