[Eric in the Ozarks]

What round does the M-21 use ?

[Rifleman]

.308 if I am remembering the correct rifle.

[x1stcav]

I remember it as the XM-21 and it was chambered for 7.62 NATO and shot National Match 168gr boattails. Assume the chambering is still the same but no doubt improvements in ammo have occured.

[JakeSladder]

This link may have some info on the M-21
http://www.specwarnet.com/kit/m21.htm