What would you recommend for a decent rifle + ammo combo for equipping a firing squad ?

Im thinking that a detail of half a dozen men per perp, armed with a bolt action of calibre not less than 7.62mm on a full cartridge.

Using a bolt action rifle to avoid flying brass that could interrupt the dignity of the proceedings ... but with a full magazine of 5-10 rounds minimum to keep things moving along.

May have to get through a lot ... so speed could become an issue.

No time for this "give each detail a mix of blank and ball, so nobody can be sure if they fired the fatal shot." ... that's simply not necessary in this case.

Recommendations ?