I have loaded 180 gr. TSX in my Sendero 300 RUM. It took quite a few trys to get the C.O.L. right but it was worth it. At 100 yrds., 3 shot groups, it shot .14" center to center. I almost got discouraged with the bullet until I talked w/ the tech. support at Barnes. They were very helpful and encouraged me to continue on. After about 30 - 35 loads, I hit jackpot. I shot a 180lbs. boar last week at about 100 - 120 yrds. The bullet retained 179 gr. of 180 gr. The hog accually did a complete flip at impact. I shot the hog in the head which had a .30" entrance hole and about a 2" exit hole. I shot through 7 gal. of water at 100 yrds to retrieve the bullet. The bullet was almost 3 times the size in diameter.