DWM
The Swedes have been using it for their military and competition for many years. Bullets are far more advanced for mid to long range because of this.
When 1000 yard benchrest was born here in Pennsylvania the 6.5/300 Wby was the caliber (along with the 30/378 Wby to a certain extent)that was the most popular with the 139 grain Norma Expert bullet with it's very flat tracjectory (only about 12' drop from a 200 yd zero or there abouts), good powders were also available then like H570 (extruded not ball), X283 and a few others. Then the good bullets were no longer available, the 30 caliber took over and still holds the reins, but recently good bullets became available and the 6.5 is back and very competitive even in much smaller cases than the 6.5/300 Wby (less barrel erosion, etc), plus a lot of new good powders.
Dan