Bore Diameter affect Bullet Seat Depth

[l115a3]

Hi,



I just received 2 rifles from local gunsmith. Both were build on Stiller Tac 30.

• Bartlein Barrel 5R HV 1:10 tw (.300/.308 Bore)

• Bartlein Barrel 5R M24 1:11.25 tw (.299/.308 Bore)


Both barrel were chamber with the same reamer PTG F-TR .342"nk , .168 fb with 1-30

The suffer problem that I got from different in bore diameter was their Seat Depth to touch the land.


(.300/.308 Bore)
168 SMK
COAL = 2.900" , CBTO = 2.325"
175 SMK
COAL = 2.910" , CBTO = 2.325"
175 LRBT
COAL = 2.990" , CBTO = 2.329"


(.299/.308 Bore)
168 SMK
COAL = 2.770" , CBTO = 2.200"
175 SMK
COAL = 2.780" , CBTO = 2.210"
175 LRBT
COAL = 2.890" , CBTO = 2.226


Do any members have an experienced of different in bore diameter?

The smaller of .001" bore will affect these huge number of Seat Depth around .100"?



Best Regards,
GSG

 

[waste_knot]

CBTO = Cartridge Base to ogive.
Can't comment on a 300/308 as both of mine are 299/308 Bartlien 11.25 on a TAC 300. My CBTO is 2.200 with 168 SMK

 

[l115a3]

CBTO = Cartridge Bas to ogive.
Can't comment on a 300/308 as both of mine are 299/308 Bartlien 11.25 on a TAC 300. My CBTO is 2.200 with 168 SMK

What spec of reamer that you use to chamber your barrel? The number of seat depth was the same as my .299/.308 too