Load Specifications
Load data in caliber .25 GT with .257 | 115gr | Barnes XLC S bullet and 98 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Power Pro 2000-MR, ReloadSwiss RS 60 and ReloadSwiss RS 52.
Important Notice: DO NOT go below Minimum Charge or above Maximum Charge. Since we have no control over the equipment and components used, any responsibility and liability for the results achieved is rejected.
Only powders/loads that match the current filter criteria are displayed: max pressure of a load ≤ 90% of max. standardized pressure, fill rate ≥ 80% and propellant combustion ≥ 95%. Use the sliders above the tables to adjust these thresholds.
Charge: Powder weight in grains. Start with the minimum load and work up carefully.
FR (Fill Rate): Case fill as a percentage. Values above 100% mean compressed loads.
MaxP / %: Maximum chamber pressure in bar and as a percentage of the standardized maximum for this caliber.
V(0): Muzzle velocity in feet per second (fps) at the standardized barrel length.
z (Powder Burn): Estimated propellant combustion percentage at bullet exit.
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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 86% | 53,766 psi | 87% | 2608 fps | 100% |
| Accurate 2460 | <<locked>> | 84% | 55,854 psi | 90% | 2677 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 55,840 psi | 90% | 2677 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 53,809 psi | 87% | 2690 fps | 100% |
| Accurate 4064 | <<locked>> | 94% | 55,317 psi | 89% | 2717 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 50,038 psi | 81% | 2720 fps | 98.2% |
| Accurate LT-30 | <<locked>> | 82% | 55,724 psi | 90% | 2589 fps | 100% |
| ADI AR 2206H | <<locked>> | 90% | 55,564 psi | 90% | 2736 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 94% | 53,258 psi | 86% | 2684 fps | 99% |
| ADI Benchmark 8208 | <<locked>> | 88% | 54,679 psi | 88% | 2690 fps | 99.9% |
| Alliant AR-Comp | <<locked>> | 88% | 54,723 psi | 88% | 2674 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 82% | 53,417 psi | 86% | 2749 fps | 99.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 92% | 54,621 psi | 88% | 2838 fps | 99.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 52,866 psi | 85% | 2710 fps | 99.8% |
| Alliant Reloder-10x | <<locked>> | 82% | 53,432 psi | 86% | 2608 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 92% | 53,432 psi | 86% | 2723 fps | 99.2% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 48,892 psi | 79% | 2717 fps | 98.2% |
| Alliant Reloder-17 | <<locked>> | 98% | 52,837 psi | 85% | 2812 fps | 99.8% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 35,404 psi | 57% | 2467 fps | 96% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 54,795 psi | 88% | 2589 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 90% | 55,042 psi | 89% | 2746 fps | 99% |
| Bofors RP3 | <<locked>> | 94% | 53,563 psi | 86% | 2726 fps | 99.9% |
| Hodgdon Benchmark | <<locked>> | 86% | 53,780 psi | 87% | 2635 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 53,766 psi | 87% | 2723 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 86% | 55,027 psi | 89% | 2808 fps | 99.4% |
| Hodgdon H322 | <<locked>> | 84% | 55,332 psi | 89% | 2690 fps | 100% |
| Hodgdon H335 | <<locked>> | 82% | 53,069 psi | 86% | 2671 fps | 100% |
| Hodgdon H380 | <<locked>> | 94% | 54,360 psi | 88% | 2726 fps | 98.4% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 52,808 psi | 85% | 2759 fps | 96.1% |
| Hodgdon H4895 | <<locked>> | 90% | 56,072 psi | 90% | 2746 fps | 99.8% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 45,353 psi | 73% | 2612 fps | 98.8% |
| Hodgdon LEVERevolution | <<locked>> | 92% | 54,418 psi | 88% | 2772 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,433 psi | 57% | 1631 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 53,780 psi | 87% | 2697 fps | 99.7% |
| IMR 3031 | <<locked>> | 90% | 55,695 psi | 90% | 2736 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 56,101 psi | 90% | 2717 fps | 99.4% |
| IMR 4166 Enduron | <<locked>> | 90% | 53,069 psi | 86% | 2641 fps | 96% |
| IMR 4198 | <<locked>> | 82% | 53,229 psi | 86% | 2569 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 98% | 55,477 psi | 89% | 2707 fps | 96.3% |
| IMR 4831ᴾ | <<locked>> | 100% | 47,616 psi | 77% | 2664 fps | 97.9% |
| IMR 4895 | <<locked>> | 92% | 54,708 psi | 88% | 2756 fps | 99.6% |
| IMR 8208 XBR | <<locked>> | 88% | 54,679 psi | 88% | 2690 fps | 99.9% |
| Lovex D073.5 | <<locked>> | 84% | 55,883 psi | 90% | 2690 fps | 100% |
| Lovex D073.6 | <<locked>> | 90% | 55,434 psi | 89% | 2723 fps | 100% |
| Lovex S060 | <<locked>> | 90% | 55,724 psi | 90% | 2667 fps | 99.6% |
| Lovex S062 | <<locked>> | 94% | 55,782 psi | 90% | 2717 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 54,607 psi | 88% | 2703 fps | 97.7% |
| Lovex S070ᴾ | <<locked>> | 100% | 52,112 psi | 84% | 2684 fps | 96.1% |
| Norma 201 | <<locked>> | 90% | 54,781 psi | 88% | 2687 fps | 99.9% |
| Norma 202 | <<locked>> | 90% | 54,853 psi | 88% | 2694 fps | 100% |
| Norma 203B | <<locked>> | 94% | 55,854 psi | 90% | 2762 fps | 99.7% |
| Norma URPᴾ | <<locked>> | 100% | 49,197 psi | 79% | 2707 fps | 98% |
| Ramshot Big Game | <<locked>> | 94% | 55,840 psi | 90% | 2782 fps | 99.6% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 48,356 psi | 78% | 2690 fps | 96% |
| Ramshot TAC | <<locked>> | 88% | 55,114 psi | 89% | 2703 fps | 97.9% |
| Ramshot Wild Boar | <<locked>> | 88% | 54,273 psi | 88% | 2723 fps | 99.5% |
| Ramshot X-Terminator | <<locked>> | 84% | 52,707 psi | 85% | 2648 fps | 99.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,781 psi | 58% | 1667 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 54,520 psi | 88% | 2680 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 54,781 psi | 88% | 2707 fps | 97% |
| ReloadSwiss RS 52 | <<locked>> | 90% | 52,852 psi | 85% | 2782 fps | 99.2% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 52,431 psi | 85% | 2815 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 49,487 psi | 80% | 2740 fps | 97.9% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 50,198 psi | 81% | 2753 fps | 97.3% |
| Rottweil R 901 | <<locked>> | 86% | 53,359 psi | 86% | 2635 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 55,521 psi | 90% | 2690 fps | 100% |
| Rottweil R 903 | <<locked>> | 96% | 52,939 psi | 85% | 2710 fps | 99.7% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 54,607 psi | 88% | 2703 fps | 97.7% |
| Shooters World Match Rifle | <<locked>> | 90% | 55,434 psi | 89% | 2723 fps | 100% |
| Shooters World Precision | <<locked>> | 94% | 55,782 psi | 90% | 2717 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 52,112 psi | 84% | 2684 fps | 96.1% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 54,201 psi | 87% | 2648 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 96% | 54,128 psi | 87% | 2766 fps | 99.5% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 54,027 psi | 87% | 2628 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 53,838 psi | 87% | 2687 fps | 98.2% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 53,679 psi | 87% | 2703 fps | 99.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 88% | 53,461 psi | 86% | 2592 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 96% | 55,941 psi | 90% | 2628 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 55,332 psi | 89% | 2661 fps | 96.4% |
| Somchem S321 | <<locked>> | 84% | 52,997 psi | 85% | 2684 fps | 99.9% |
| Somchem S335 | <<locked>> | 90% | 55,593 psi | 90% | 2631 fps | 100% |
| Somchem S341 | <<locked>> | 88% | 52,997 psi | 85% | 2680 fps | 99.3% |
| Somchem S355 | <<locked>> | 96% | 53,635 psi | 87% | 2710 fps | 99.7% |
| Somchem S365ᴾ | <<locked>> | 100% | 44,295 psi | 71% | 2664 fps | 99.6% |
| Vihtavuori N130 | <<locked>> | 84% | 53,476 psi | 86% | 2566 fps | 100% |
| Vihtavuori N133 | <<locked>> | 88% | 53,359 psi | 86% | 2582 fps | 100% |
| Vihtavuori N135 | <<locked>> | 92% | 54,404 psi | 88% | 2657 fps | 100% |
| Vihtavuori N140 | <<locked>> | 92% | 55,361 psi | 89% | 2671 fps | 100% |
| Vihtavuori N150 | <<locked>> | 98% | 54,665 psi | 88% | 2690 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 51,764 psi | 83% | 2703 fps | 98.3% |
| Vihtavuori N530 | <<locked>> | 88% | 55,608 psi | 90% | 2697 fps | 100% |
| Vihtavuori N540 | <<locked>> | 92% | 53,476 psi | 86% | 2671 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 51,111 psi | 82% | 2713 fps | 98.1% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 37,666 psi | 61% | 2546 fps | 96.1% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 52,533 psi | 85% | 2687 fps | 99.7% |
| Winchester 748 | <<locked>> | 88% | 54,839 psi | 88% | 2743 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 52,808 psi | 85% | 2759 fps | 96.1% |
| Winchester StaBALL Match | <<locked>> | 90% | 53,432 psi | 86% | 2713 fps | 99.7% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 45,556 psi | 73% | 2487 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 49,110 psi | 79% | 2582 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 39,233 psi | 63% | 2428 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 44,469 psi | 72% | 2546 fps | 99.9% |
| Accurate 4064 | <<locked>> | 80% | 37,043 psi | 60% | 2415 fps | 99.7% |
| Accurate 4350 | <<locked>> | 92% | 38,595 psi | 62% | 2516 fps | 95.6% |
| Accurate LT-30 | <<locked>> | 80% | 52,446 psi | 85% | 2543 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 41,684 psi | 67% | 2500 fps | 97.7% |
| ADI AR 2208 | <<locked>> | 80% | 35,346 psi | 57% | 2352 fps | 95% |
| ADI Benchmark 8208 | <<locked>> | 80% | 43,482 psi | 70% | 2510 fps | 99% |
| Alliant AR-Comp | <<locked>> | 80% | 43,004 psi | 69% | 2510 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 50,241 psi | 81% | 2697 fps | 99.5% |
| Alliant Power Pro 2000-MR | 29.6 gr | 80% | 37,492 psi | 60% | 2507 fps | 95.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 34,925 psi | 56% | 2379 fps | 96.9% |
| Alliant Reloder-10x | <<locked>> | 80% | 50,662 psi | 82% | 2572 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 37,666 psi | 61% | 2438 fps | 96.1% |
| Alliant Reloder-16 | <<locked>> | 92% | 38,914 psi | 63% | 2520 fps | 95.5% |
| Alliant Reloder-17 | <<locked>> | 84% | 34,360 psi | 55% | 2441 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 98% | 33,692 psi | 54% | 2425 fps | 95.2% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 51,793 psi | 84% | 2546 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 40,205 psi | 65% | 2493 fps | 96.2% |
| Bofors RP3 | <<locked>> | 80% | 34,853 psi | 56% | 2388 fps | 97% |
| Hodgdon Benchmark | <<locked>> | 80% | 45,078 psi | 73% | 2497 fps | 99.5% |
| Hodgdon BL-C2 | <<locked>> | 80% | 41,916 psi | 68% | 2530 fps | 99.2% |
| Hodgdon CFE223 | <<locked>> | 80% | 45,397 psi | 73% | 2648 fps | 98% |
| Hodgdon H322 | <<locked>> | 80% | 48,907 psi | 79% | 2598 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 49,966 psi | 81% | 2625 fps | 100% |
| Hodgdon H380 | <<locked>> | 84% | 40,147 psi | 65% | 2480 fps | 95.3% |
| Hodgdon H414 | <<locked>> | 98% | 49,719 psi | 80% | 2710 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 41,959 psi | 68% | 2510 fps | 98.3% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 33,852 psi | 55% | 2372 fps | 95.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 37,579 psi | 61% | 2477 fps | 97.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,658 psi | 43% | 1460 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 40,103 psi | 65% | 2464 fps | 97.8% |
| IMR 3031 | <<locked>> | 80% | 40,828 psi | 66% | 2510 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 37,057 psi | 60% | 2382 fps | 95.9% |
| IMR 4166 Enduron | <<locked>> | 88% | 50,053 psi | 81% | 2592 fps | 95.3% |
| IMR 4198 | <<locked>> | 80% | 50,473 psi | 81% | 2530 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 94% | 49,298 psi | 80% | 2612 fps | 95% |
| IMR 4831 | <<locked>> | 92% | 37,289 psi | 60% | 2470 fps | 95.2% |
| IMR 4895 | <<locked>> | 80% | 38,450 psi | 62% | 2467 fps | 97% |
| IMR 8208 XBR | <<locked>> | 80% | 43,482 psi | 70% | 2510 fps | 99% |
| Lovex D073.5 | <<locked>> | 80% | 49,124 psi | 79% | 2592 fps | 99.9% |
| Lovex D073.6 | <<locked>> | 80% | 40,451 psi | 65% | 2487 fps | 99.6% |
| Lovex S060 | <<locked>> | 80% | 41,800 psi | 67% | 2438 fps | 97.7% |
| Lovex S062 | <<locked>> | 80% | 37,333 psi | 60% | 2398 fps | 97.9% |
| Lovex S065 | <<locked>> | 92% | 43,482 psi | 70% | 2520 fps | 95.3% |
| Lovex S070 | <<locked>> | 98% | 49,095 psi | 79% | 2635 fps | 95.4% |
| Norma 201 | <<locked>> | 80% | 41,350 psi | 67% | 2464 fps | 98.7% |
| Norma 202 | <<locked>> | 80% | 40,930 psi | 66% | 2470 fps | 99.8% |
| Norma 203B | <<locked>> | 80% | 37,072 psi | 60% | 2428 fps | 96.5% |
| Norma URP | <<locked>> | 92% | 38,972 psi | 63% | 2513 fps | 95.5% |
| Ramshot Big Game | <<locked>> | 80% | 36,158 psi | 58% | 2431 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 98% | 45,600 psi | 74% | 2644 fps | 95.2% |
| Ramshot TAC | <<locked>> | 80% | 43,062 psi | 69% | 2500 fps | 95.4% |
| Ramshot Wild Boar | <<locked>> | 80% | 42,482 psi | 69% | 2526 fps | 97.8% |
| Ramshot X-Terminator | <<locked>> | 80% | 46,557 psi | 75% | 2546 fps | 98.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,716 psi | 43% | 1490 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 48,283 psi | 78% | 2585 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 45,861 psi | 74% | 2562 fps | 95% |
| ReloadSwiss RS 52 | 28.7 gr | 80% | 38,595 psi | 62% | 2523 fps | 96.4% |
| ReloadSwiss RS 60 | 29.1 gr | 80% | 32,155 psi | 52% | 2395 fps | 97.5% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 40,886 psi | 66% | 2582 fps | 95.8% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 44,150 psi | 71% | 2641 fps | 95.7% |
| Rottweil R 901 | <<locked>> | 80% | 45,498 psi | 73% | 2510 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 39,479 psi | 64% | 2421 fps | 98.3% |
| Rottweil R 903 | <<locked>> | 80% | 32,967 psi | 53% | 2339 fps | 96% |
| Shooters World Long Rifle | <<locked>> | 92% | 43,482 psi | 70% | 2520 fps | 95.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 40,451 psi | 65% | 2487 fps | 99.6% |
| Shooters World Precision | <<locked>> | 80% | 37,333 psi | 60% | 2398 fps | 97.9% |
| Shooters World SW4350 | <<locked>> | 98% | 49,095 psi | 79% | 2635 fps | 95.4% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 51,024 psi | 82% | 2602 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 33,460 psi | 54% | 2372 fps | 95% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 50,676 psi | 82% | 2582 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 41,626 psi | 67% | 2480 fps | 95.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 40,030 psi | 65% | 2467 fps | 97.3% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 42,105 psi | 68% | 2415 fps | 99.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 34,954 psi | 56% | 2293 fps | 99.7% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 48,718 psi | 79% | 2562 fps | 95% |
| Somchem S321 | <<locked>> | 80% | 46,673 psi | 75% | 2585 fps | 99.6% |
| Somchem S335 | <<locked>> | 80% | 42,192 psi | 68% | 2428 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 41,046 psi | 66% | 2480 fps | 97.4% |
| Somchem S355 | <<locked>> | 80% | 33,808 psi | 55% | 2343 fps | 96% |
| Somchem S365 | <<locked>> | 86% | 29,602 psi | 48% | 2323 fps | 95.5% |
| Vihtavuori N130 | <<locked>> | 80% | 47,369 psi | 76% | 2477 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 42,061 psi | 68% | 2411 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 37,956 psi | 61% | 2405 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 38,856 psi | 63% | 2411 fps | 99.8% |
| Vihtavuori N150 | <<locked>> | 80% | 32,010 psi | 52% | 2283 fps | 96.9% |
| Vihtavuori N160 | <<locked>> | 90% | 38,203 psi | 62% | 2461 fps | 95% |
| Vihtavuori N530 | <<locked>> | 80% | 43,468 psi | 70% | 2503 fps | 99.1% |
| Vihtavuori N540 | <<locked>> | 80% | 37,449 psi | 60% | 2402 fps | 99.4% |
| Vihtavuori N550 | <<locked>> | 92% | 39,885 psi | 64% | 2516 fps | 95.5% |
| Vihtavuori N555 | <<locked>> | 98% | 35,491 psi | 57% | 2493 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 32,343 psi | 52% | 2300 fps | 95% |
| Winchester 748 | <<locked>> | 80% | 42,525 psi | 69% | 2546 fps | 99.5% |
| Winchester 760 | <<locked>> | 98% | 49,719 psi | 80% | 2710 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 39,218 psi | 63% | 2470 fps | 97.7% |
Recommended = one of the top powders for this cartridge and bullet combination.
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 109 powders for .25 GT loaded with the .257 | 115gr | Barnes XLC S. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,838 fps; across all powders the maximum-charge window runs from 1,631 fps to 2,838 fps. Accurate 3100 gives the best case fill at 100 %, and 109 of the 109 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (427 MPa), the top charges use 51–90 %, leaving at least 10 % headroom. The 115.0 gr projectile in 0.257" calls for a 1:9.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate 4350, Alliant Reloder-16 reach 100 % fill or more at maximum charge, so these are compressed loads: they need a long drop tube to seat cleanly and react sensitively to the case capacity of your own brass lot. Alliant Power Pro 2000-MR, ReloadSwiss RS 60, ReloadSwiss RS 52 rank at the top here: for .25 GT with the .257 | 115gr | Barnes XLC S they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 3100, Alliant Reloder-26, Hodgdon H4350 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.