Load Specifications
Load data in caliber .300 RCM with .308 | 146.6gr | Sax KDG-S bullet and 95 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 52 and ReloadSwiss RS 60.
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% | 57,580 psi | 90% | 2953 fps | 100% |
| Accurate 2460 | <<locked>> | 86% | 56,362 psi | 88% | 2982 fps | 100% |
| Accurate 2495 | <<locked>> | 94% | 55,013 psi | 86% | 2969 fps | 100% |
| Accurate 2520 | <<locked>> | 88% | 54,462 psi | 85% | 2995 fps | 100% |
| Accurate 4064 | <<locked>> | 96% | 54,911 psi | 86% | 3012 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 47,166 psi | 74% | 2953 fps | 97.4% |
| Accurate LT-30 | <<locked>> | 84% | 57,348 psi | 90% | 2904 fps | 100% |
| Accurate LT-32 | <<locked>> | 82% | 54,520 psi | 85% | 2884 fps | 100% |
| ADI AR 2206H | <<locked>> | 92% | 56,913 psi | 89% | 3054 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 96% | 54,447 psi | 85% | 2992 fps | 98.9% |
| ADI AR 2219 | <<locked>> | 82% | 54,737 psi | 86% | 2979 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 90% | 56,202 psi | 88% | 3005 fps | 99.9% |
| Alliant AR-Comp | <<locked>> | 90% | 56,072 psi | 88% | 2986 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 84% | 54,172 psi | 85% | 3064 fps | 99.6% |
| Alliant Power Pro 2000-MR | <<locked>> | 94% | 56,768 psi | 89% | 3169 fps | 99.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 98% | 57,421 psi | 90% | 3068 fps | 99.9% |
| Alliant Reloder-10x | <<locked>> | 86% | 57,624 psi | 90% | 2966 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 94% | 54,563 psi | 86% | 3035 fps | 99.1% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 47,050 psi | 74% | 2966 fps | 97.5% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 54,650 psi | 86% | 3133 fps | 99.8% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 56,652 psi | 89% | 2897 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 92% | 56,956 psi | 89% | 3068 fps | 99% |
| Bofors RP3 | <<locked>> | 96% | 53,940 psi | 85% | 3025 fps | 99.8% |
| Hodgdon Benchmark | <<locked>> | 88% | 54,853 psi | 86% | 2943 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 90% | 55,056 psi | 86% | 3035 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 88% | 57,377 psi | 90% | 3140 fps | 99.4% |
| Hodgdon H322 | <<locked>> | 86% | 56,898 psi | 89% | 3009 fps | 100% |
| Hodgdon H335 | <<locked>> | 84% | 54,592 psi | 86% | 2986 fps | 100% |
| Hodgdon H380 | <<locked>> | 96% | 55,796 psi | 87% | 3041 fps | 98.3% |
| Hodgdon H4895 | <<locked>> | 92% | 57,421 psi | 90% | 3064 fps | 99.8% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 43,033 psi | 67% | 2841 fps | 98.1% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 56,420 psi | 88% | 3094 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,563 psi | 54% | 1827 fps | 100% |
| Hodgdon VARGET | <<locked>> | 92% | 55,405 psi | 87% | 3015 fps | 99.7% |
| IMR 3031 | <<locked>> | 92% | 56,739 psi | 89% | 3048 fps | 100% |
| IMR 4064 | <<locked>> | 96% | 57,392 psi | 90% | 3028 fps | 99.4% |
| IMR 4166 Enduron | <<locked>> | 92% | 54,795 psi | 86% | 2956 fps | 96% |
| IMR 4198 | <<locked>> | 86% | 57,740 psi | 90% | 2923 fps | 100% |
| IMR 4451 Enduronᴾ | <<locked>> | 100% | 57,276 psi | 90% | 3025 fps | 96.4% |
| IMR 4831ᴾ | <<locked>> | 100% | 45,020 psi | 71% | 2894 fps | 97% |
| IMR 4895 | <<locked>> | 94% | 55,912 psi | 88% | 3071 fps | 99.6% |
| IMR 8208 XBR | <<locked>> | 90% | 56,202 psi | 88% | 3005 fps | 99.9% |
| Lovex D073.5 | <<locked>> | 86% | 56,434 psi | 88% | 2995 fps | 100% |
| Lovex D073.6 | <<locked>> | 92% | 56,173 psi | 88% | 3028 fps | 100% |
| Lovex S060 | <<locked>> | 92% | 57,000 psi | 89% | 2979 fps | 99.6% |
| Lovex S062 | <<locked>> | 96% | 56,594 psi | 89% | 3025 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 52,373 psi | 82% | 2956 fps | 97% |
| Norma 200 | <<locked>> | 82% | 57,072 psi | 89% | 2933 fps | 100% |
| Norma 201 | <<locked>> | 92% | 55,390 psi | 87% | 2995 fps | 99.9% |
| Norma 202 | <<locked>> | 92% | 55,985 psi | 88% | 3002 fps | 100% |
| Norma 203B | <<locked>> | 96% | 57,217 psi | 90% | 3077 fps | 99.6% |
| Norma URPᴾ | <<locked>> | 100% | 47,297 psi | 74% | 2953 fps | 97.3% |
| Ramshot Big Game | <<locked>> | 94% | 54,331 psi | 85% | 3048 fps | 99.3% |
| Ramshot TAC | <<locked>> | 90% | 56,826 psi | 89% | 3018 fps | 97.9% |
| Ramshot Wild Boar | <<locked>> | 90% | 56,043 psi | 88% | 3041 fps | 99.5% |
| Ramshot X-Terminator | <<locked>> | 88% | 57,725 psi | 90% | 3012 fps | 99.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,838 psi | 55% | 1870 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 86% | 55,869 psi | 88% | 2995 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 96% | 56,318 psi | 88% | 3015 fps | 97% |
| ReloadSwiss RS 52 | <<locked>> | 92% | 54,679 psi | 86% | 3104 fps | 99.1% |
| ReloadSwiss RS 60 | <<locked>> | 98% | 54,447 psi | 85% | 3140 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 47,108 psi | 74% | 2972 fps | 97.1% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 48,356 psi | 76% | 2999 fps | 96.5% |
| Rottweil R 901 | <<locked>> | 90% | 56,188 psi | 88% | 2979 fps | 100% |
| Rottweil R 902 | <<locked>> | 94% | 55,825 psi | 87% | 2992 fps | 99.9% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 57,551 psi | 90% | 3071 fps | 99.9% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 52,373 psi | 82% | 2956 fps | 97% |
| Shooters World Match Rifle | <<locked>> | 92% | 56,173 psi | 88% | 3028 fps | 100% |
| Shooters World Precision | <<locked>> | 96% | 56,594 psi | 89% | 3025 fps | 100% |
| Shooters World Tactical Rifle | <<locked>> | 84% | 55,854 psi | 88% | 2963 fps | 99.8% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 57,145 psi | 90% | 2641 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 82% | 55,143 psi | 86% | 2989 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 98% | 55,941 psi | 88% | 3081 fps | 99.5% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 55,027 psi | 86% | 2940 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 90% | 54,998 psi | 86% | 2995 fps | 98.1% |
| SNPE Vectan SP 9 | <<locked>> | 92% | 55,376 psi | 87% | 3022 fps | 99.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 92% | 57,740 psi | 90% | 2943 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 98% | 57,493 psi | 90% | 2933 fps | 100% |
| Somchem S321 | <<locked>> | 88% | 57,609 psi | 90% | 3045 fps | 100% |
| Somchem S335 | <<locked>> | 92% | 56,594 psi | 89% | 2936 fps | 100% |
| Somchem S341 | <<locked>> | 90% | 54,317 psi | 85% | 2986 fps | 99.3% |
| Somchem S355 | <<locked>> | 98% | 54,288 psi | 85% | 3012 fps | 99.6% |
| Somchem S365ᴾ | <<locked>> | 100% | 41,930 psi | 66% | 2894 fps | 99.1% |
| Vihtavuori N130 | <<locked>> | 88% | 57,348 psi | 90% | 2910 fps | 100% |
| Vihtavuori N133 | <<locked>> | 92% | 57,682 psi | 90% | 2930 fps | 100% |
| Vihtavuori N135 | <<locked>> | 94% | 54,955 psi | 86% | 2959 fps | 100% |
| Vihtavuori N140 | <<locked>> | 94% | 56,637 psi | 89% | 2979 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 56,304 psi | 88% | 2999 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 49,777 psi | 78% | 2953 fps | 97.7% |
| Vihtavuori N530 | <<locked>> | 90% | 56,884 psi | 89% | 3009 fps | 100% |
| Vihtavuori N540 | <<locked>> | 94% | 54,636 psi | 86% | 2972 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 48,733 psi | 76% | 2953 fps | 97.3% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 51,024 psi | 80% | 2943 fps | 99.4% |
| Winchester 748 | <<locked>> | 90% | 56,188 psi | 88% | 3054 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 92% | 55,100 psi | 86% | 3028 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% | 42,047 psi | 66% | 2713 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 45,818 psi | 72% | 2818 fps | 99.9% |
| Accurate 2495 | <<locked>> | 80% | 34,040 psi | 53% | 2602 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 41,002 psi | 64% | 2766 fps | 99.4% |
| Accurate 4064 | <<locked>> | 80% | 32,242 psi | 51% | 2582 fps | 98.5% |
| Accurate 4350 | <<locked>> | 96% | 40,814 psi | 64% | 2828 fps | 95.7% |
| Accurate LT-30 | <<locked>> | 80% | 50,734 psi | 80% | 2808 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 51,140 psi | 80% | 2831 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 38,740 psi | 61% | 2713 fps | 96.5% |
| ADI AR 2208 | <<locked>> | 84% | 37,420 psi | 59% | 2664 fps | 95.2% |
| ADI AR 2219 | <<locked>> | 80% | 51,227 psi | 80% | 2927 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 40,799 psi | 64% | 2733 fps | 98.2% |
| Alliant AR-Comp | <<locked>> | 80% | 39,914 psi | 63% | 2740 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 47,355 psi | 74% | 2943 fps | 98.9% |
| Alliant Power Pro 2000-MR | 53.9 gr | 84% | 40,132 psi | 63% | 2841 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 31,937 psi | 50% | 2569 fps | 95.1% |
| Alliant Reloder-10x | <<locked>> | 80% | 47,805 psi | 75% | 2822 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 36,941 psi | 58% | 2694 fps | 95.3% |
| Alliant Reloder-16 | <<locked>> | 96% | 41,379 psi | 65% | 2844 fps | 95.9% |
| Alliant Reloder-17 | <<locked>> | 88% | 36,201 psi | 57% | 2753 fps | 96% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 49,719 psi | 78% | 2799 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 40,350 psi | 63% | 2766 fps | 95.7% |
| Bofors RP3 | <<locked>> | 82% | 33,330 psi | 52% | 2618 fps | 95.9% |
| Hodgdon Benchmark | <<locked>> | 80% | 42,699 psi | 67% | 2730 fps | 99% |
| Hodgdon BL-C2 | <<locked>> | 80% | 38,870 psi | 61% | 2740 fps | 98.3% |
| Hodgdon CFE223 | <<locked>> | 80% | 42,888 psi | 67% | 2881 fps | 97.1% |
| Hodgdon H322 | <<locked>> | 80% | 46,601 psi | 73% | 2851 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 47,500 psi | 74% | 2871 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 42,627 psi | 67% | 2805 fps | 95.6% |
| Hodgdon H4895 | <<locked>> | 80% | 39,015 psi | 61% | 2726 fps | 97.2% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 35,447 psi | 56% | 2674 fps | 95.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 34,896 psi | 55% | 2680 fps | 96.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,498 psi | 40% | 1631 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 37,565 psi | 59% | 2677 fps | 96.6% |
| IMR 3031 | <<locked>> | 80% | 38,101 psi | 60% | 2736 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 36,724 psi | 58% | 2644 fps | 95.3% |
| IMR 4166 Enduron | <<locked>> | 90% | 51,169 psi | 80% | 2894 fps | 95.2% |
| IMR 4198 | <<locked>> | 80% | 48,414 psi | 76% | 2789 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 98% | 53,766 psi | 84% | 2969 fps | 95.7% |
| IMR 4831 | <<locked>> | 96% | 39,320 psi | 62% | 2779 fps | 95.4% |
| IMR 4895 | <<locked>> | 80% | 35,375 psi | 55% | 2667 fps | 95.4% |
| IMR 8208 XBR | <<locked>> | 80% | 40,799 psi | 64% | 2733 fps | 98.2% |
| Lovex D073.5 | <<locked>> | 80% | 45,643 psi | 72% | 2822 fps | 99.6% |
| Lovex D073.6 | <<locked>> | 80% | 36,883 psi | 58% | 2687 fps | 98.7% |
| Lovex S060 | <<locked>> | 80% | 39,465 psi | 62% | 2661 fps | 96.7% |
| Lovex S062 | <<locked>> | 80% | 34,127 psi | 53% | 2595 fps | 96.5% |
| Lovex S065 | <<locked>> | 96% | 46,325 psi | 73% | 2848 fps | 95.6% |
| Norma 200 | <<locked>> | 80% | 53,534 psi | 84% | 2884 fps | 100% |
| Norma 201 | <<locked>> | 80% | 37,681 psi | 59% | 2667 fps | 97.5% |
| Norma 202 | <<locked>> | 80% | 37,956 psi | 59% | 2687 fps | 99.4% |
| Norma 203B | <<locked>> | 82% | 36,289 psi | 57% | 2680 fps | 95.7% |
| Norma URP | <<locked>> | 96% | 41,379 psi | 65% | 2835 fps | 95.7% |
| Ramshot Big Game | <<locked>> | 82% | 35,853 psi | 56% | 2687 fps | 95.2% |
| Ramshot TAC | <<locked>> | 82% | 43,700 psi | 68% | 2785 fps | 95.1% |
| Ramshot Wild Boar | <<locked>> | 80% | 39,900 psi | 63% | 2746 fps | 96.8% |
| Ramshot X-Terminator | <<locked>> | 80% | 44,164 psi | 69% | 2782 fps | 97.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,643 psi | 40% | 1670 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 45,832 psi | 72% | 2828 fps | 99.7% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 49,298 psi | 77% | 2900 fps | 95.5% |
| ReloadSwiss RS 52 | 51 gr | 82% | 38,348 psi | 60% | 2792 fps | 95.7% |
| ReloadSwiss RS 60 | 50.5 gr | 80% | 29,414 psi | 46% | 2569 fps | 95.4% |
| ReloadSwiss RS 62 | <<locked>> | 96% | 40,988 psi | 64% | 2851 fps | 95.3% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 45,078 psi | 71% | 2933 fps | 95.6% |
| Rottweil R 901 | <<locked>> | 80% | 41,408 psi | 65% | 2726 fps | 99.6% |
| Rottweil R 902 | <<locked>> | 80% | 35,984 psi | 56% | 2618 fps | 97% |
| Rottweil R 903 | <<locked>> | 84% | 33,431 psi | 52% | 2615 fps | 95.5% |
| Shooters World Long Rifle | <<locked>> | 96% | 46,325 psi | 73% | 2848 fps | 95.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 36,883 psi | 58% | 2687 fps | 98.7% |
| Shooters World Precision | <<locked>> | 80% | 34,127 psi | 53% | 2595 fps | 96.5% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 48,515 psi | 76% | 2844 fps | 99.2% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 54,215 psi | 85% | 2605 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 51,488 psi | 81% | 2933 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 34,954 psi | 55% | 2671 fps | 95% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 48,689 psi | 76% | 2844 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 41,452 psi | 65% | 2749 fps | 95.1% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 37,376 psi | 59% | 2680 fps | 96% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 39,624 psi | 62% | 2644 fps | 99.5% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 32,503 psi | 51% | 2497 fps | 99% |
| Somchem S321 | <<locked>> | 80% | 43,714 psi | 69% | 2812 fps | 99% |
| Somchem S335 | <<locked>> | 80% | 38,899 psi | 61% | 2641 fps | 99.8% |
| Somchem S341 | <<locked>> | 80% | 38,290 psi | 60% | 2690 fps | 96.2% |
| Somchem S355 | <<locked>> | 84% | 34,693 psi | 54% | 2628 fps | 95.7% |
| Somchem S365 | <<locked>> | 90% | 30,139 psi | 47% | 2595 fps | 95.1% |
| Vihtavuori N130 | <<locked>> | 80% | 45,005 psi | 71% | 2726 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 39,827 psi | 62% | 2648 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 34,998 psi | 55% | 2618 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 35,969 psi | 56% | 2621 fps | 99.3% |
| Vihtavuori N150 | <<locked>> | 80% | 28,877 psi | 45% | 2457 fps | 95% |
| Vihtavuori N160 | <<locked>> | 94% | 40,741 psi | 64% | 2782 fps | 95.4% |
| Vihtavuori N530 | <<locked>> | 80% | 40,683 psi | 64% | 2726 fps | 98.3% |
| Vihtavuori N540 | <<locked>> | 80% | 34,447 psi | 54% | 2598 fps | 98.6% |
| Vihtavuori N550 | <<locked>> | 96% | 42,757 psi | 67% | 2841 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 33,924 psi | 53% | 2589 fps | 95.2% |
| Winchester 748 | <<locked>> | 80% | 39,711 psi | 62% | 2766 fps | 98.7% |
| Winchester StaBALL Match | <<locked>> | 80% | 36,448 psi | 57% | 2677 fps | 96.4% |
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 95 powders for .300 RCM loaded with the .308 | 146.6gr | Sax KDG-S. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,169 fps; across all powders the maximum-charge window runs from 1,827 fps to 3,169 fps. Accurate 4350 gives the best case fill at 100 %, and 95 of the 95 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 54–90 %, leaving at least 10 % headroom. The 146.6 gr projectile in 0.308" calls for a 1:12.5 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, ReloadSwiss RS 52, ReloadSwiss RS 60 rank at the top here: for .300 RCM with the .308 | 146.6gr | Sax KDG-S they combine a high case fill with complete burn and sit in the upper velocity band. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.