How would one go about lengthening a standard length BRNO 600 or CZ 550 magazine box and action to accommodate a longer OAL? Thinking of 8x68s or 300 H&H on a standard length action. Standard box length is 87.5 or 88mm, if I recall correctly. Would like to take it out to 91mm and not use the magnum length action. I know that this has been done before but I have not been able to reach the smiths that I know have done the work.

Could it be done like the Whitworth rifles with milling the action and spot welding an extension onto the front of the mag box?

Could one cut out the front wall of the mag box like has been done on some 98 Jeffery conversions?

Could one mill off the front box lip on the bottom off the action and fit the lengthened mag box?


Semper Fi