2 dimensions to freebore?

[thefitter]

I found this blerb somewhere, can't remember where I just cut it and saved it for later. I states that there are 2 dimensions for freebore. The width and the length.

"The freebore is a straightline cylindrical space that does have the
lands removed but it is usually a pinch bigger than the bottom of the
groove. The diameter is approximately 0.0002" to 0.0005" larger in
diameter than the groove diameter. In this description of a .308 Win. it
means that the freebore diameter would measure 0.3082" - 0.3085" depending
on the specification by the buyer or SAAMI. The length of the freebore is
variable also, from 0.000" to 0.500" to allow for a pressure decrease or
the seating out of extremely long VLD bullets."

 

[Webster]

I read somewhere that the free bore can have a taper. One benchrest shooter said he had a 1.5 degree taper in his freebore.

 

[CanusLatransSnpr]

If I'm not mistaken, the 1.5 degree leade made it's appearance during the inception of the 6ppc! Somebody figured out that setup was inherently more accurate than the others and the 1.5 degree kinda became standard on br rounds.

Mike

 

[expiper]

the 1.5 degree dim. is the angle that the freebore portion of the chamber tapers from groove to bore dia.....this reamer print should answer all questions..Roger

 

[treeman]

There seems to be a lot of confusion on this subject. freebore is straight /cylindrical. leade is tapered from the freebore/ groove diameter to bore diameter. a chamber doesn't have to have freebore but must have leade. hope this makes sense

 

[M-61]

There seems to be a lot of confusion on this subject. freebore is straight /cylindrical. leade is tapered from the freebore/ groove diameter to bore diameter. a chamber doesn't have to have freebore but must have leade. hope this makes sense

Is this the difference (or one of) between a 5.56 chamber (Mil Spec) and a commercial .223? I am referring to the leade angle.