Stolen from AR.
"Mark II RSM Rifle, 3 Generations, by my recollection, not quotable for dates, the rest is accurate:
First Generation: 1989 announcement, 1990 production: Heavy 24" barrel with barrel band sling base inletted through the forearm.
Second Generation, about 1994: Same heavy 24" barrel but with barrel band sling base out on the barrel beyond forend tip.
Third Generation, about 2004: 23" barrel of lighter contour, otherwise same as Gen2.
Initially only .375 H&H and .416 Rigby, IIRC, but .458 Lott was out in 2006 for sure."
http://forums.accuratereloading.com/eve/forums/a/tpc/f/4711043/m/3181075971
