TPI on .250 bolt

[mikendi]

The forarm on a Martini 22 rifle has a retaining bolt that mic's .250 and is between 28 and 32 TPI.. Does anyone know the the tap that I need...Thanks.

 

[papapaul]

You should check with a thread gage. Somebody may have re-threaded it and it may not be as issued.

 

[blades]

Might want to check it with a metric thread gauge.

 

[crb]

It could be Whitworth but most likely it's something unique. May not have a 60 degree angle.

 

[John Kielly]

I thought it might be a BA thread, but that pitch is slower than 28. What about the ME range? http://www.tapdie.com/html/me__dies.html

 

[gunsmither]

Perhaps re- tap it to 1/4- 28?

It might be 1/4-30 ? You can find a tap and die possibly, or re- tap the hole 1/4-28, and make a new screw.

 

[mikendi]

OK, I rethreaded the bolt and tapped the barrel to 1/4 28.

Where is the best place to get the gunsmith sizes of tap sets, if someone could tell me.. Thanks in advance

 

[Rflshootr]

Try Brownell's