Quote Originally Posted by gghbi View Post
30-06 = 7.62 X 61 and 308 = 7.62 x 51 or 10 mm less which is 4/10 inch. I put my money on it being a 308 chamber. Do let us know what the gunsmith finds.

EDIT: you can download a marketing brochure from here: http://www.forgottenweapons.com/mads...ilitary-rifle/
Turns out you were right !

Took the rifle to my gunsmith and it is indeed chambered in .308. No evidence of any modifications or bushings. Madsen did manufacture the rifle in different calibers, apparently this is an odd duck in terms of the ones bought by the Colombian Navy ?