It was made in
30/06, 8x57, 7.62x51, 7x57 and 7.65x53
for
Argentina, Belgium, Brazil, Colombia, Egypt, Indonesia, Luxembourg and Venezuela
I have rebarrelled an Egyptian to the same 8x57 using a barrel from Marstar. I am prepared to be corrected, but aside from the 30/06 which has a different mag, it would just be a barrel switch to move between chamberings. Fine adjustments for headspace are made by replacing a knock-out "wedge" with others of different sizes, but I imagine that they are non-existent, so you'd be stuck with using a finishing reamer for that.