Deep throat? (Neck, throat, chamber reamers?)

Elric

Well-Known Member
I've been a bit busy the past six months or so...

I'd like to get more space for a 280468-S in a 6.8mm SPC in a Contender. Problem is that the gas check is JUST within the neck. Supposedly, the SPC II spec adds another .050 to the throat?

Where is a good explanation of throat, leade, and freebore? I'm seeing the SPC II -may- have a wider neck, which I don't need....

o_O
 

Elric

Well-Known Member
Where is a good explanation of throat, leade, and freebore? This is not 6.8 SPC specific. Before looking for a tool, I need to know what I want done.
 

RBHarter

West Central AR
Throat is the transition from the case mouth to the groove dia .
Leade is the rifling taper from groove dia to full depth .......or high as it were .

Long throats like Weatherby have as much .2 of the barrel that is without any rifling at full groove diameter .
The SPCII has had throats from .05 out to .15 .
The function of the longer throat is to allow hotter loads to run lower chamber pressures .


The above is either right or exactly term backwards .......... Apologies for that . CB has a thread with cut away of an actual barrel .
 

fiver

Well-Known Member
I would give SAAMI a try.
looking at a couple of different cartridge/chamber drawings should clear things up a little.
they ain't really labeled but you can see clearly the ball seat area the throat taper and any chambering with free bore cut into them.