When positioned all the way forward, bolt carriers tend to tilt downward at the back causing the bolt face
to be set at an angle.
magazines are wider, the bolt face
is bigger to fit around the case head, and the cartridge itself occupies more real estate than one for a rifle chambered in .223 Rem.
Hopefully, a conversion would require only a new barrel as the bolt face
and cartridge length should be compatible.
Safety was a primary concern when the Mark V was designed, so the rifle features three rings of steel around the cartridge base: recessed bolt face
, receiver and barrel.
It was made overlong and then fitted later to obtain the desired .045" to .055" firing pin protrusion out of the bolt face
. The cap was shaped like a screw head with a 3/16" hole drilled in one end so it could slide over the pin.
Preliminary tests of the existing Savage Model 12 bolt face
and extractor clearly revealed that the extractor claw would not extend far enough into the bolt face
to reliably latch on to the smaller .224 Valkyrie case rim.
The circular and flat ejector face cuts a small arc along the case head for approximately 22 1/2 degrees, the same amount of rotation as the bolt face
in an AR.
A scaled-up bolt and bolt face
, bolt carrier, and upper receiver makes it possible to accommodate the .308 round.
A shallow shear groove was cut right under the head so its head could be snapped off and filed down flush with the bolt face
This will not allow the tilted condition described between the bolt face
, the cartridge, and the barrel.
The bolt face
was opened to fit the standard .223 Rem.
The bottom of the bolt face
is relieved to allow the case head to slide smoothly up the bolt face
with its rim beneath the extractor hook.