Bore size of 7mm barrel?

Desertbull,

Rifled bores may be described by the bore diameter (the diameter across the lands or high points in the rifling), or by groove diameter (the diameter across the grooves or low points in the rifling).
Differences in naming conventions for cartridges can cause confusion; for example, the .303 British is actually slightly larger in diameter than the .308 Winchester, because the ".303" refers to the bore diameter in inches, while the ".308" refers to the groove diameter in inches (7.70 mm and 7.62 mm, respectively).
Hope this helps. JohnnyK.
 
They just made a mistake on their website. It says 7mm (.277) instead of 7mm(.284). They are all 7mm(.284) cartridges listed.
 
.277" is the most common bore diameter for a 7mm although Brux 7mm barrels are .276".
FYI 7 millimeters converted to inches = .27559".

Standard 7mm groove diameter is .284"

James
 
.277" is the most common bore diameter for a 7mm although Brux 7mm barrels are .276".
FYI 7 millimeters converted to inches = .27559".

Standard 7mm groove diameter is .284"

James


OK, I can buy that, but then why did they list all of their other barrels in standard American barrel designations (.308, .257, .243) and they don't even list a .270 Winchester as a standard cartridge? What kind of a barrel MFG makes barrels for 6mm but not for a .270 Winchester?
 
They just made a mistake on their website. It says 7mm (.277) instead of 7mm(.284). They are all 7mm(.284) cartridges listed.

Some barrel makers give you the land diameter and others give you the groove diameter, and
some give you both.

The ones that give you the land or both diameter's are normally cut rifling and they are telling
you how deep the grooves are. (.284 groove Dia. and a .277 land Dia. = .0035 groove depth, or
three and one half thousandths).

But just to make sure I would call them and verify that it is for a .284 bullet.

J E CUSTOM
 
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