Hi Ash,
In its basic form YES, a 7mm slimline or streamline... The. 308 (7.62) cases are the same length as the kit tube.... You are replacing the wooden/acrylic jacket with a metal one.
Drill the cartridge case with a 7mm hole(checking first it's fired) then bond in the kit tube(a couple of wraps of masking tape will take up the slack in the cartridge mouth.... Once dry push the kit fittings in.
I go a little further by using real bullet points, these have the lead removed and are a swaged fit with a 2mm hole at the tip. This means you can't use a 7mm tube so I drill a 1/4" hole at the back and push the transmission straight in.
Other cartridges can be done and among them I have done...
223, 243, 270, 303, 308, 30 06, 30 30, 338, 470NE, 500NE and. 50BMG