Free bore question

N

nhkuehl

Guest
I had a friend ask me: What is a normal free bore diameter (over bullet diameter) for a bench rest rifle? and, Are bench rest rifles are chambered +.002" at the neck?

My friend shoots high power with a Wylde chamber. "A common high power chambering has a longer throat with smaller free bore diameter (right at bullet diameter or +.0002"). The chamber in a semi-auto has to have +.005" at the neck diameter."

I'll defer to the forum on that and maybe a little discussion of free bore vs. throat.

Thanks. nhk
 
6 BR site

has reamer prints for various calibres .it might be better to see on a print I'm not sure I get your question.
 
I order my reamers with a freebore diameter of 0.0002" over the bullet I am using. On a 6mm which is usually 0.2433, I specify 0.2435" on the reamer.

Chamber neck diameter can be a bit more complicated. There is the "fitted neck" where you can seat another bullet without resizing the neck. In this fitted neck the brass is turned to 0.0005" under chamber neck.

Normal neck clearance though is 0.002" between the brass and chamber neck.

Then there is a new emergence. Some of the new top guns in the centerfire 100/200 game, some of these new entrants to the HOF are using 0.0035". "Loose to win" they call it.

Then there is the step-neck where the brass is turned with a step on the outside that ends where the shooter wants the bullet base to be. After firing, this step (about 0.0005" moves to the inside. Ferris Pindell used this some.
 
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6mm BR site

j mckinnie said:
has reamer prints for various calibres .it might be better to see on a print I'm not sure I get your question.
Click to expand...

I go there all the time and have only seen cartridge diagrams, could you give me the link to a 6mm BR reamer print? Thanks. nhk
 
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