Load Specifications
Load data in caliber .300 RCM with .308 | 138gr | Hammer HHT bullet and 97 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, Hodgdon CFE223 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.
A valid access license is required to use the Personalized Load Calculator.
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>> | 90% | 55,622 psi | 87% | 3018 fps | 100% |
| Accurate 2200 | <<locked>> | 82% | 55,724 psi | 87% | 3117 fps | 98.6% |
| Accurate 2230 | <<locked>> | 82% | 56,956 psi | 89% | 3127 fps | 99% |
| Accurate 2460 | <<locked>> | 86% | 53,983 psi | 85% | 3035 fps | 100% |
| Accurate 2495 | <<locked>> | 96% | 56,115 psi | 88% | 3071 fps | 100% |
| Accurate 2520 | <<locked>> | 90% | 55,811 psi | 87% | 3100 fps | 100% |
| Accurate 4064 | <<locked>> | 98% | 55,782 psi | 87% | 3114 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 44,715 psi | 70% | 2986 fps | 96.1% |
| Accurate LT-30 | <<locked>> | 84% | 55,564 psi | 87% | 2966 fps | 100% |
| Accurate LT-32 | <<locked>> | 84% | 56,014 psi | 88% | 2989 fps | 100% |
| ADI AR 2206H | <<locked>> | 92% | 54,578 psi | 86% | 3100 fps | 99% |
| ADI AR 2207 | <<locked>> | 82% | 56,869 psi | 89% | 2982 fps | 100% |
| ADI AR 2208 | <<locked>> | 98% | 55,695 psi | 87% | 3094 fps | 98.7% |
| ADI AR 2219 | <<locked>> | 84% | 56,463 psi | 88% | 3094 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 92% | 57,508 psi | 90% | 3114 fps | 99.8% |
| Alliant AR-Comp | <<locked>> | 92% | 57,276 psi | 90% | 3097 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 86% | 55,463 psi | 87% | 3173 fps | 99.5% |
| Alliant Power Pro 2000-MR | <<locked>> | 94% | 54,505 psi | 85% | 3215 fps | 98.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 98% | 54,853 psi | 86% | 3117 fps | 99.6% |
| Alliant Reloder-10x | <<locked>> | 86% | 55,506 psi | 87% | 3031 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 96% | 55,941 psi | 88% | 3140 fps | 98.9% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 44,962 psi | 70% | 2999 fps | 96.2% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 52,315 psi | 82% | 3173 fps | 99.3% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 54,940 psi | 86% | 2959 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 92% | 54,737 psi | 86% | 3114 fps | 98.3% |
| Bofors RP3 | <<locked>> | 98% | 55,201 psi | 87% | 3130 fps | 99.6% |
| Hodgdon Benchmark | <<locked>> | 90% | 56,318 psi | 88% | 3048 fps | 99.9% |
| Hodgdon BL-C2 | <<locked>> | 92% | 56,652 psi | 89% | 3146 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 88% | 54,607 psi | 86% | 3182 fps | 98.8% |
| Hodgdon H322 | <<locked>> | 86% | 54,926 psi | 86% | 3071 fps | 100% |
| Hodgdon H335 | <<locked>> | 86% | 56,101 psi | 88% | 3097 fps | 100% |
| Hodgdon H380 | <<locked>> | 98% | 57,188 psi | 90% | 3143 fps | 98% |
| Hodgdon H4198 | <<locked>> | 82% | 57,435 psi | 90% | 3015 fps | 100% |
| Hodgdon H4895 | <<locked>> | 92% | 55,100 psi | 86% | 3114 fps | 99.4% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 40,988 psi | 64% | 2874 fps | 96.9% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 54,027 psi | 85% | 3143 fps | 99.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,243 psi | 54% | 1883 fps | 100% |
| Hodgdon VARGET | <<locked>> | 94% | 56,985 psi | 89% | 3123 fps | 99.5% |
| IMR 3031 | <<locked>> | 92% | 54,433 psi | 85% | 3110 fps | 100% |
| IMR 4064 | <<locked>> | 96% | 55,347 psi | 87% | 3081 fps | 98.8% |
| IMR 4198 | <<locked>> | 86% | 55,854 psi | 88% | 2989 fps | 100% |
| IMR 4895 | <<locked>> | 96% | 57,319 psi | 90% | 3176 fps | 99.4% |
| IMR 8208 XBR | <<locked>> | 92% | 57,508 psi | 90% | 3114 fps | 99.8% |
| Lovex D073.4 | <<locked>> | 82% | 57,493 psi | 90% | 3104 fps | 100% |
| Lovex D073.5 | <<locked>> | 86% | 54,012 psi | 85% | 3045 fps | 99.9% |
| Lovex D073.6 | <<locked>> | 94% | 57,551 psi | 90% | 3136 fps | 100% |
| Lovex S060 | <<locked>> | 92% | 54,969 psi | 86% | 3031 fps | 99.1% |
| Lovex S062 | <<locked>> | 96% | 54,447 psi | 85% | 3074 fps | 99.7% |
| Lovex S065ᴾ | <<locked>> | 100% | 50,328 psi | 79% | 2995 fps | 95.9% |
| Norma 200 | <<locked>> | 82% | 55,013 psi | 86% | 2995 fps | 100% |
| Norma 201 | <<locked>> | 94% | 56,666 psi | 89% | 3097 fps | 99.8% |
| Norma 202 | <<locked>> | 94% | 57,203 psi | 90% | 3110 fps | 100% |
| Norma 203B | <<locked>> | 96% | 54,969 psi | 86% | 3127 fps | 99.1% |
| Norma URPᴾ | <<locked>> | 100% | 44,918 psi | 70% | 2982 fps | 96% |
| Ramshot Big Game | <<locked>> | 96% | 55,782 psi | 87% | 3153 fps | 99.1% |
| Ramshot TAC | <<locked>> | 90% | 54,868 psi | 86% | 3068 fps | 97% |
| Ramshot Wild Boar | <<locked>> | 92% | 57,740 psi | 90% | 3150 fps | 99.3% |
| Ramshot X-Terminator | <<locked>> | 88% | 55,535 psi | 87% | 3061 fps | 99% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,476 psi | 54% | 1926 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 88% | 57,551 psi | 90% | 3107 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 96% | 54,172 psi | 85% | 3061 fps | 95.9% |
| ReloadSwiss RS 52 | <<locked>> | 94% | 55,854 psi | 88% | 3209 fps | 98.9% |
| ReloadSwiss RS 60ᴾ | <<locked>> | 100% | 55,956 psi | 88% | 3248 fps | 100% |
| Rottweil R 901 | <<locked>> | 92% | 57,551 psi | 90% | 3087 fps | 100% |
| Rottweil R 902 | <<locked>> | 96% | 57,101 psi | 89% | 3094 fps | 99.8% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 54,781 psi | 86% | 3114 fps | 99.5% |
| Shooters World AR Plus | <<locked>> | 82% | 57,493 psi | 90% | 3104 fps | 100% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 50,328 psi | 79% | 2995 fps | 95.9% |
| Shooters World Match Rifle | <<locked>> | 94% | 57,551 psi | 90% | 3136 fps | 100% |
| Shooters World Precision | <<locked>> | 96% | 54,447 psi | 85% | 3074 fps | 99.7% |
| Shooters World Tactical Rifle | <<locked>> | 86% | 57,609 psi | 90% | 3071 fps | 99.7% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 55,869 psi | 88% | 2710 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 84% | 56,724 psi | 89% | 3100 fps | 100% |
| SNPE Vectan SP 11ᴾ | <<locked>> | 100% | 57,406 psi | 90% | 3186 fps | 99.3% |
| SNPE Vectan SP 3 | <<locked>> | 86% | 56,623 psi | 89% | 3054 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 92% | 56,478 psi | 89% | 3097 fps | 97.8% |
| SNPE Vectan SP 9 | <<locked>> | 94% | 56,797 psi | 89% | 3127 fps | 99.3% |
| SNPE Vectan Tubal 3000 | <<locked>> | 92% | 55,608 psi | 87% | 2999 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 98% | 55,463 psi | 87% | 2992 fps | 100% |
| Somchem S321 | <<locked>> | 88% | 55,492 psi | 87% | 3097 fps | 99.8% |
| Somchem S335 | <<locked>> | 92% | 54,476 psi | 85% | 2992 fps | 100% |
| Somchem S341 | <<locked>> | 92% | 55,985 psi | 88% | 3094 fps | 99.1% |
| Somchem S355ᴾ | <<locked>> | 100% | 55,608 psi | 87% | 3117 fps | 99.4% |
| Somchem S365ᴾ | <<locked>> | 100% | 40,016 psi | 63% | 2927 fps | 98.2% |
| Vihtavuori N120 | <<locked>> | 82% | 56,724 psi | 89% | 2930 fps | 100% |
| Vihtavuori N130 | <<locked>> | 88% | 55,332 psi | 87% | 2969 fps | 100% |
| Vihtavuori N133 | <<locked>> | 92% | 55,506 psi | 87% | 2986 fps | 100% |
| Vihtavuori N135 | <<locked>> | 96% | 56,115 psi | 88% | 3068 fps | 100% |
| Vihtavuori N140 | <<locked>> | 94% | 54,215 psi | 85% | 3031 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 53,722 psi | 84% | 3045 fps | 99.8% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 47,572 psi | 75% | 2992 fps | 96.6% |
| Vihtavuori N530 | <<locked>> | 90% | 54,621 psi | 86% | 3058 fps | 99.7% |
| Vihtavuori N540 | <<locked>> | 96% | 56,014 psi | 88% | 3077 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 46,528 psi | 73% | 2989 fps | 96.2% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 48,994 psi | 77% | 2982 fps | 98.8% |
| Winchester 748 | <<locked>> | 92% | 57,580 psi | 90% | 3163 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 94% | 56,739 psi | 89% | 3136 fps | 99.6% |
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% | 40,379 psi | 63% | 2762 fps | 100% |
| Accurate 2200 | <<locked>> | 80% | 52,156 psi | 82% | 3054 fps | 98% |
| Accurate 2230 | <<locked>> | 80% | 52,997 psi | 83% | 3064 fps | 98.5% |
| Accurate 2460 | <<locked>> | 80% | 43,874 psi | 69% | 2864 fps | 99.6% |
| Accurate 2495 | <<locked>> | 80% | 32,372 psi | 51% | 2641 fps | 99.7% |
| Accurate 2520 | <<locked>> | 80% | 39,146 psi | 61% | 2805 fps | 98.8% |
| Accurate 4064 | <<locked>> | 80% | 30,647 psi | 48% | 2615 fps | 97.5% |
| Accurate 4350 | <<locked>> | 98% | 41,568 psi | 65% | 2923 fps | 95.2% |
| Accurate LT-30 | <<locked>> | 80% | 49,182 psi | 77% | 2864 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 49,545 psi | 78% | 2887 fps | 99.9% |
| ADI AR 2206H | <<locked>> | 80% | 37,144 psi | 58% | 2753 fps | 95.2% |
| ADI AR 2207 | <<locked>> | 80% | 53,577 psi | 84% | 2940 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 40,886 psi | 64% | 2818 fps | 95.6% |
| ADI AR 2219 | <<locked>> | 80% | 49,197 psi | 77% | 2979 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 39,233 psi | 61% | 2776 fps | 97.3% |
| Alliant AR-Comp | <<locked>> | 80% | 37,985 psi | 60% | 2789 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 45,353 psi | 71% | 2989 fps | 98.1% |
| Alliant Power Pro 2000-MR | 55.5 gr | 86% | 41,191 psi | 65% | 2940 fps | 95.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 34,896 psi | 55% | 2717 fps | 95.6% |
| Alliant Reloder-10x | <<locked>> | 80% | 45,788 psi | 72% | 2877 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 40,292 psi | 63% | 2844 fps | 95.7% |
| Alliant Reloder-16 | <<locked>> | 98% | 42,177 psi | 66% | 2933 fps | 95.3% |
| Alliant Reloder-17 | <<locked>> | 90% | 37,043 psi | 58% | 2844 fps | 95.4% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 48,254 psi | 76% | 2858 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 41,568 psi | 65% | 2867 fps | 95.3% |
| Bofors RP3 | <<locked>> | 84% | 33,924 psi | 53% | 2707 fps | 95.3% |
| Hodgdon Benchmark | <<locked>> | 80% | 41,220 psi | 65% | 2779 fps | 98.3% |
| Hodgdon BL-C2 | <<locked>> | 80% | 37,144 psi | 58% | 2779 fps | 97.3% |
| Hodgdon CFE223 | 52.8 gr | 80% | 40,915 psi | 64% | 2917 fps | 95.8% |
| Hodgdon H322 | <<locked>> | 80% | 44,759 psi | 70% | 2900 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 45,556 psi | 71% | 2920 fps | 99.9% |
| Hodgdon H380 | <<locked>> | 90% | 43,453 psi | 68% | 2897 fps | 95.1% |
| Hodgdon H4198 | <<locked>> | 80% | 54,157 psi | 85% | 2969 fps | 100% |
| Hodgdon H4895 | <<locked>> | 80% | 37,420 psi | 59% | 2766 fps | 96% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 36,100 psi | 57% | 2759 fps | 95.2% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 35,766 psi | 56% | 2776 fps | 95.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,280 psi | 40% | 1683 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 36,085 psi | 57% | 2717 fps | 95.4% |
| IMR 3031 | <<locked>> | 80% | 36,085 psi | 57% | 2776 fps | 99.7% |
| IMR 4064 | <<locked>> | 86% | 40,219 psi | 63% | 2799 fps | 95.7% |
| IMR 4198 | <<locked>> | 80% | 46,804 psi | 73% | 2851 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 36,172 psi | 57% | 2762 fps | 95% |
| IMR 8208 XBR | <<locked>> | 80% | 39,233 psi | 61% | 2776 fps | 97.3% |
| Lovex D073.4 | <<locked>> | 80% | 53,780 psi | 84% | 3048 fps | 100% |
| Lovex D073.5 | <<locked>> | 80% | 43,671 psi | 68% | 2864 fps | 99% |
| Lovex D073.6 | <<locked>> | 80% | 35,128 psi | 55% | 2723 fps | 97.8% |
| Lovex S060 | <<locked>> | 80% | 38,101 psi | 60% | 2703 fps | 95.6% |
| Lovex S062 | <<locked>> | 80% | 32,706 psi | 51% | 2631 fps | 95.2% |
| Lovex S065 | <<locked>> | 98% | 47,239 psi | 74% | 2940 fps | 95.1% |
| Norma 200 | <<locked>> | 80% | 51,605 psi | 81% | 2946 fps | 100% |
| Norma 201 | <<locked>> | 80% | 36,187 psi | 57% | 2707 fps | 96.5% |
| Norma 202 | <<locked>> | 80% | 36,390 psi | 57% | 2726 fps | 98.7% |
| Norma 203B | <<locked>> | 84% | 37,057 psi | 58% | 2772 fps | 95.3% |
| Norma URP | <<locked>> | 98% | 42,032 psi | 66% | 2923 fps | 95.1% |
| Ramshot Big Game | <<locked>> | 86% | 39,363 psi | 62% | 2844 fps | 95.7% |
| Ramshot TAC | <<locked>> | 86% | 48,008 psi | 75% | 2946 fps | 95.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 38,189 psi | 60% | 2785 fps | 95.5% |
| Ramshot X-Terminator | <<locked>> | 80% | 42,496 psi | 67% | 2822 fps | 96.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,382 psi | 40% | 1719 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 44,034 psi | 69% | 2874 fps | 99.3% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 50,575 psi | 79% | 2999 fps | 95.1% |
| ReloadSwiss RS 52 | 52.6 gr | 84% | 39,276 psi | 62% | 2890 fps | 95.3% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 32,343 psi | 51% | 2726 fps | 96.1% |
| Rottweil R 901 | <<locked>> | 80% | 39,624 psi | 62% | 2769 fps | 99.1% |
| Rottweil R 902 | <<locked>> | 80% | 34,316 psi | 54% | 2651 fps | 95.8% |
| Rottweil R 903 | <<locked>> | 86% | 34,026 psi | 53% | 2703 fps | 95% |
| Shooters World AR Plus | <<locked>> | 80% | 53,780 psi | 84% | 3048 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 98% | 47,239 psi | 74% | 2940 fps | 95.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 35,128 psi | 55% | 2723 fps | 97.8% |
| Shooters World Precision | <<locked>> | 80% | 32,706 psi | 51% | 2631 fps | 95.2% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 46,644 psi | 73% | 2890 fps | 98.5% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 52,968 psi | 83% | 2671 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 49,472 psi | 78% | 2986 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 38,377 psi | 60% | 2828 fps | 95.5% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 46,630 psi | 73% | 2897 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 45,643 psi | 72% | 2910 fps | 95.5% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 38,218 psi | 60% | 2776 fps | 95.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 37,971 psi | 60% | 2687 fps | 98.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 31,024 psi | 49% | 2533 fps | 98.2% |
| Somchem S321 | <<locked>> | 80% | 42,119 psi | 66% | 2858 fps | 98.3% |
| Somchem S335 | <<locked>> | 80% | 37,449 psi | 59% | 2687 fps | 99.4% |
| Somchem S341 | <<locked>> | 80% | 36,811 psi | 58% | 2730 fps | 95% |
| Somchem S355 | <<locked>> | 86% | 35,418 psi | 56% | 2720 fps | 95.2% |
| Somchem S365 | <<locked>> | 94% | 32,706 psi | 51% | 2736 fps | 95.5% |
| Vihtavuori N120 | <<locked>> | 80% | 53,447 psi | 84% | 2884 fps | 100% |
| Vihtavuori N130 | <<locked>> | 80% | 43,192 psi | 68% | 2776 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 38,116 psi | 60% | 2694 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 33,199 psi | 52% | 2654 fps | 99.7% |
| Vihtavuori N140 | <<locked>> | 80% | 34,243 psi | 54% | 2657 fps | 98.5% |
| Vihtavuori N150 | <<locked>> | 84% | 31,401 psi | 49% | 2595 fps | 95.3% |
| Vihtavuori N160 | <<locked>> | 98% | 44,512 psi | 70% | 2933 fps | 95.8% |
| Vihtavuori N530 | <<locked>> | 80% | 39,059 psi | 61% | 2769 fps | 97.3% |
| Vihtavuori N540 | <<locked>> | 80% | 32,953 psi | 52% | 2638 fps | 97.7% |
| Vihtavuori N550 | <<locked>> | 98% | 43,555 psi | 68% | 2933 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 37,362 psi | 59% | 2740 fps | 95.7% |
| Winchester 748 | <<locked>> | 80% | 37,898 psi | 59% | 2805 fps | 97.8% |
| Winchester StaBALL Match | <<locked>> | 80% | 34,824 psi | 55% | 2713 fps | 95.1% |
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 116 powders for .300 RCM loaded with the .308 | 138gr | Hammer HHT. ReloadSwiss RS 60 delivers the highest muzzle velocity at 3,248 fps; across all powders the maximum-charge window runs from 1,883 fps to 3,248 fps. Accurate 4350 gives the best case fill at 100 %, and 116 of the 116 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 49–90 %, leaving at least 10 % headroom. The 138.0 gr projectile in 0.308" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. Accurate 4350, Alliant Reloder-16, Alliant Reloder-17 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, Hodgdon CFE223, ReloadSwiss RS 52 rank at the top here: for .300 RCM with the .308 | 138gr | Hammer HHT they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 2700, Alliant Reloder-23, Bofors RP7 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.