how long is a chamber reamer live pilot?

[shawnba67]

I cant seem to find this dimension online anywhere. I am wondering how deep into the bore the pilot goes before say the shoulder portion starts cutting? Any one got one they could measure for me?
(Example question: Would the pilot be in the bore at the start of cutting a 223 chamber to 22-250 or is the lathe holding it true for that first bit?)

 

[30calmachinegunner]

I think it will depend on the manufacturer, but to answer your question, if you were to open a .223 chamber up to a 22-250 I would say you would start making contact on the chamber diameter BEFORE any pilot would be in the bore, from memory most pilots are about 1/2" long at most

 

[shawnba67]

Thanks 30cal