I got two boxes of 130 grain Sierra Game Changer TGK bullets on Saturday and I put together two loads with IMR4451 Enduron powder for my Savage 12 LRP.
Temperature was between 34 and 44 degrees over a two-hour period with winds calm to 2 mph.

Shot four 5-round groups with each of 2 TGK loads using Lapua brass and CCI BR-4 primers. The 8 groups averaged 0.377
Under Load Description - data lists Powder, charge, O.A.L., bullet weight, Bullet type, case trim length, primer, wf 1.361 refers to the exit time from the 26-inch barrel, brass and primer size.
# Grps Load Description Bullet Weight Velocity Best Grp % MOA Average %MOA Median St Dev Grp 1 Grp 2 Grp 3 Grp 4
4 IMR 4451 39.2 2.865 130 TGK 2711 case 1.912 BR-4 wf 1.361 * Lapua SRP Tipped Game Changer #4330 130 2711 0.239 22.8% 0.362 34.6% 0.373 0.097 0.239 0.337 0.409 0.464
4 IMR 4451 39.2 2.868 130 TGK 2711 case 1.912 BR-4 wf 1.361 * Lapua SRP Tipped Game Changer #4330 130 2710 0.258 24.6% 0.392 37.4% 0.423 0.092 0.258 0.422 0.423 0.465


For comparison, I also shot 130 Grain Sierra Tipped Match King bullets with the IMR4451 powder and CCI BR-4 primers with Lapua brass. The 8 groups averaged 0.376
# Grps Load Description Bullet Weight Velocity Best Grp % MOA Average %MOA Median St Dev Grp 1 Grp 2 Grp 3 Grp 4
4 IMR 4451 39.0 2.866 130 TMK 2702 case 1.910 CCIBR-4 wf 1.361 * Lapua SRP 42/39 deg F Tipped Match King # 7430 130 2701 0.229 21.9% 0.357 34.1% 0.388 0.087 0.229 0.382 0.394 0.423
4 IMR 4451 39.0 2.868 130 TMK 2701 case 1.909 CCIBR-4 wf 1.361 * Lapua SRP 44/44 deg F Tipped Match King # 7430 130 2702 0.369 35.2% 0.395 37.7% 0.396 0.020 0.369 0.395 0.397 0.418

The Game Changers seem to shoot as well as the Tipped Match Kings.
Another comparison, the Hornady 143 ELD-X bullets average 0.353 with IMR4451 Enduron powder based upon 46 groups.
But this particular 12 LRP likes heavier bullets.