Screw Cut Thread Query

[mildot]

Hi just need abit of advise.

 

I have 2 rifle with 1/2" unf threads on and 2 different mods with the same threads. Now i can swap the mods from one rifle to another without a prob.

 

However a friend has got a rifle with what looks to be 1/2" thread too. it came with a thread protector which screws on fine. It also screw on fine for both my rifles. BUT if i try to fit either of my mods to his rifles they dont seem to wanna thread on more than one turn!

 

The thread on his rilfe doesnt look to be 1/2"unef as his protector screws onto my normal 1/2" thread.

 

Any Ideas?

 

 

UPDATE

 

I have measured with a micrometer the distance over a set amount of turns and they are the same. the outside diameter is 0.5".

 

I screwed the protector onto one and gave it a wiggle to see how much play there is and then onto the other. His rifle has less play!

 

Im lost now!

[Guest varmartin]

Simple...his thread is larger than yours...his cap is bigger so will fit your rifles threads..being smaller

[mildot]

He went for it and used brute force! lol

 

Apparantly its ok but just nice and snug fit. Must be where tha barrel had an overly worn die/tap!

[Guest varmartin]

If it was a home DIY tread cut...he probably did use a die ..LOL

 

There are fixed size and split adjustable dies which have a screw to expand the die for a better fit.

Hexagon rethreading dies are also available to clean up existing threads....maybe he could use one of these ???

 

 

Tongue in cheek

[mildot]

A hammer will do the job! always works! lol