Load Specifications
Bullet Manufacturer:A-Square
Bullet Weight:300 gr
Bullet Diameter:0.375"
Bullet Length:<<locked>>
Caliber:37 XC load data
Case Length (l3):3.087"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:139.8 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:30"
Max. allowed Pressure:69,618 psi
Recommended Twist Rate:1:6.0
Load data in caliber 37 XC with .375 | 300gr | A-Square MONO RN bullet and 96 powders. The key underlying parameters are shown in the table above.
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: 30"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 82% | 61,960 psi | 89% | 2854 fps | 100% |
| Accurate 3100 | <<locked>> | 96% | 59,190 psi | 85% | 2877 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 62,323 psi | 90% | 2808 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 60,626 psi | 87% | 2904 fps | 100% |
| Accurate High Country | <<locked>> | 94% | 61,017 psi | 88% | 3051 fps | 100% |
| Accurate MAGPRO | <<locked>> | 96% | 62,120 psi | 89% | 3054 fps | 99.8% |
| ADI APS 450 | <<locked>> | 84% | 62,990 psi | 90% | 2221 fps | 100% |
| ADI AR 2208 | <<locked>> | 84% | 61,134 psi | 88% | 2851 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 61,366 psi | 88% | 2976 fps | 100% |
| ADI AR 2213 | <<locked>> | 96% | 58,987 psi | 85% | 2989 fps | 99.9% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 49,487 psi | 71% | 2838 fps | 99.5% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 44,150 psi | 63% | 2808 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 61,496 psi | 88% | 2972 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 62,816 psi | 90% | 2871 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 62,888 psi | 90% | 2900 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 61,395 psi | 88% | 2953 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 59,016 psi | 85% | 2923 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 60,684 psi | 87% | 2963 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 96% | 58,958 psi | 85% | 2982 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 98% | 60,263 psi | 87% | 2930 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 55,811 psi | 80% | 2953 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 61,424 psi | 88% | 3038 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 45,585 psi | 65% | 2854 fps | 96.2% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 60,481 psi | 87% | 2946 fps | 98.7% |
| Bofors RP15ᴾ | <<locked>> | 100% | 61,728 psi | 89% | 3018 fps | 100% |
| Bofors RP3 | <<locked>> | 82% | 60,336 psi | 87% | 2844 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 51,750 psi | 74% | 2913 fps | 99.8% |
| Bofors RP5 | <<locked>> | 96% | 58,958 psi | 85% | 2982 fps | 100% |
| Bofors RP7 | <<locked>> | 88% | 62,845 psi | 90% | 2907 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 54,563 psi | 78% | 2917 fps | 100% |
| Hodgdon H380 | <<locked>> | 82% | 60,234 psi | 87% | 2871 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 62,366 psi | 90% | 2966 fps | 100% |
| Hodgdon H4350 | <<locked>> | 86% | 61,105 psi | 88% | 2920 fps | 100% |
| Hodgdon H4831 | <<locked>> | 94% | 58,943 psi | 85% | 2927 fps | 99.7% |
| Hodgdon H4831 SC | <<locked>> | 96% | 61,728 psi | 89% | 2959 fps | 99.8% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 61,699 psi | 89% | 2867 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 54,592 psi | 78% | 3035 fps | 100% |
| Hodgdon Superformance | <<locked>> | 86% | 59,219 psi | 85% | 2959 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,072 psi | 53% | 1759 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 60,655 psi | 87% | 2831 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 62,903 psi | 90% | 2881 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 60,669 psi | 87% | 2894 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 86% | 60,408 psi | 87% | 2874 fps | 100% |
| IMR 4831 | <<locked>> | 90% | 60,814 psi | 87% | 2894 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 59,741 psi | 86% | 2900 fps | 99.8% |
| IMR 7828 SSC | <<locked>> | 98% | 60,974 psi | 88% | 3025 fps | 100% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 39,755 psi | 57% | 2723 fps | 98% |
| Lovex S062 | <<locked>> | 82% | 61,134 psi | 88% | 2822 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 61,090 psi | 88% | 2867 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 59,248 psi | 85% | 2871 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 56,521 psi | 81% | 2844 fps | 100% |
| Norma 203B | <<locked>> | 82% | 62,221 psi | 89% | 2884 fps | 100% |
| Norma 204 | <<locked>> | 90% | 62,221 psi | 89% | 2963 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 39,740 psi | 57% | 2746 fps | 99.6% |
| Norma MRP | <<locked>> | 94% | 59,117 psi | 85% | 3005 fps | 100% |
| Norma URP | <<locked>> | 90% | 62,569 psi | 90% | 2936 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 62,149 psi | 89% | 3045 fps | 100% |
| Ramshot Hunter | <<locked>> | 90% | 61,540 psi | 88% | 2953 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 60,394 psi | 87% | 2972 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,971 psi | 55% | 1801 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 59,828 psi | 86% | 2861 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 62,888 psi | 90% | 2953 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 60,684 psi | 87% | 2930 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 59,088 psi | 85% | 2966 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 55,303 psi | 79% | 3031 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 50,096 psi | 72% | 2930 fps | 99% |
| Rottweil R 903 | <<locked>> | 84% | 60,553 psi | 87% | 2841 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 62,497 psi | 90% | 2940 fps | 100% |
| Rottweil R 905 | <<locked>> | 94% | 60,350 psi | 87% | 2953 fps | 100% |
| Rottweil R 907 | <<locked>> | 88% | 62,845 psi | 90% | 2907 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 88% | 61,090 psi | 88% | 2867 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 61,134 psi | 88% | 2822 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 59,248 psi | 85% | 2871 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 62,265 psi | 89% | 2904 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 60,089 psi | 86% | 2700 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 60,611 psi | 87% | 2828 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 59,886 psi | 86% | 2949 fps | 100% |
| Somchem S355 | <<locked>> | 84% | 60,075 psi | 86% | 2838 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 60,466 psi | 87% | 2884 fps | 99.7% |
| Somchem S365 | <<locked>> | 90% | 59,408 psi | 85% | 2884 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 60,814 psi | 87% | 2920 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 61,395 psi | 88% | 2802 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 60,626 psi | 87% | 2874 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 60,394 psi | 87% | 2897 fps | 100% |
| Vihtavuori N170ᴾ | <<locked>> | 100% | 55,071 psi | 79% | 2864 fps | 96.4% |
| Vihtavuori N540 | <<locked>> | 82% | 61,728 psi | 89% | 2795 fps | 100% |
| Vihtavuori N550 | <<locked>> | 88% | 59,843 psi | 86% | 2887 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 62,729 psi | 90% | 2959 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 62,990 psi | 90% | 3064 fps | 100% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 58,494 psi | 84% | 2986 fps | 99.9% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 51,416 psi | 74% | 2936 fps | 98.8% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 48,472 psi | 70% | 2927 fps | 96.6% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 60,321 psi | 87% | 2828 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 62,511 psi | 90% | 2966 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 98% | 58,378 psi | 84% | 3028 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 61,046 psi | 88% | 2920 fps | 100% |
Start Load - Barrel Length: 30"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 80% | 58,088 psi | 83% | 2802 fps | 100% |
| Accurate 3100 | <<locked>> | 80% | 34,606 psi | 50% | 2477 fps | 99.1% |
| Accurate 4064 | <<locked>> | 80% | 58,537 psi | 84% | 2766 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 46,296 psi | 67% | 2703 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 37,449 psi | 54% | 2644 fps | 97% |
| Accurate MAGPRO | <<locked>> | 82% | 37,884 psi | 54% | 2641 fps | 95.8% |
| ADI APS 450 | <<locked>> | 80% | 58,987 psi | 85% | 2169 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 54,128 psi | 78% | 2759 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 38,580 psi | 55% | 2598 fps | 98.1% |
| ADI AR 2213 | <<locked>> | 80% | 34,505 psi | 50% | 2533 fps | 95.5% |
| ADI AR 2217 | <<locked>> | 88% | 33,315 psi | 48% | 2500 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 84% | 26,455 psi | 38% | 2359 fps | 95.2% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 38,957 psi | 56% | 2598 fps | 98.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 55,463 psi | 80% | 2779 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 58,972 psi | 85% | 2851 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 44,338 psi | 64% | 2713 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 51,271 psi | 74% | 2822 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 38,609 psi | 55% | 2595 fps | 98.1% |
| Alliant Reloder-22 | <<locked>> | 80% | 34,519 psi | 50% | 2546 fps | 97.2% |
| Alliant Reloder-23 | <<locked>> | 80% | 33,199 psi | 48% | 2503 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 28,906 psi | 42% | 2428 fps | 98.4% |
| Alliant Reloder-26 | <<locked>> | 80% | 36,289 psi | 52% | 2648 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 42,409 psi | 61% | 2789 fps | 95.2% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 44,469 psi | 64% | 2677 fps | 95.5% |
| Bofors RP15 | <<locked>> | 80% | 32,097 psi | 46% | 2484 fps | 96.2% |
| Bofors RP3 | <<locked>> | 80% | 56,623 psi | 81% | 2799 fps | 100% |
| Bofors RP30 | <<locked>> | 86% | 32,184 psi | 46% | 2523 fps | 95.6% |
| Bofors RP5 | <<locked>> | 80% | 34,519 psi | 50% | 2546 fps | 97.2% |
| Bofors RP7 | <<locked>> | 80% | 48,878 psi | 70% | 2707 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 84% | 31,734 psi | 46% | 2461 fps | 95.3% |
| Hodgdon H380 | <<locked>> | 80% | 56,536 psi | 81% | 2822 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 47,979 psi | 69% | 2759 fps | 100% |
| Hodgdon H4350 | <<locked>> | 80% | 50,502 psi | 73% | 2769 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 80% | 36,796 psi | 53% | 2539 fps | 95.8% |
| Hodgdon H4831 SC | <<locked>> | 80% | 36,158 psi | 52% | 2523 fps | 95.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 41,887 psi | 60% | 2595 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 82% | 30,182 psi | 43% | 2510 fps | 96.1% |
| Hodgdon Superformance | <<locked>> | 80% | 47,558 psi | 68% | 2789 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,804 psi | 40% | 1575 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 56,985 psi | 82% | 2785 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 59,161 psi | 85% | 2831 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 44,324 psi | 64% | 2644 fps | 99.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 50,212 psi | 72% | 2730 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 44,034 psi | 63% | 2651 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 38,508 psi | 55% | 2539 fps | 96.4% |
| IMR 7828 SSC | <<locked>> | 80% | 33,214 psi | 48% | 2513 fps | 95.1% |
| IMR 8133 Enduron | <<locked>> | 94% | 32,634 psi | 47% | 2552 fps | 95.6% |
| Lovex S062 | <<locked>> | 80% | 57,464 psi | 83% | 2776 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 47,834 psi | 69% | 2677 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 46,151 psi | 66% | 2677 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 29,863 psi | 43% | 2362 fps | 97.9% |
| Norma 203B | <<locked>> | 80% | 58,320 psi | 84% | 2838 fps | 100% |
| Norma 204 | <<locked>> | 80% | 44,425 psi | 64% | 2690 fps | 99.1% |
| Norma 217 | <<locked>> | 88% | 26,861 psi | 39% | 2408 fps | 95.1% |
| Norma MRP | <<locked>> | 80% | 36,071 psi | 52% | 2612 fps | 98.9% |
| Norma URP | <<locked>> | 80% | 45,382 psi | 65% | 2694 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 32,590 psi | 47% | 2513 fps | 95.3% |
| Ramshot Hunter | <<locked>> | 80% | 44,266 psi | 64% | 2697 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 29,008 psi | 42% | 2402 fps | 95.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,442 psi | 41% | 1614 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 56,130 psi | 81% | 2812 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 54,520 psi | 78% | 2854 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 46,267 psi | 66% | 2730 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 44,411 psi | 64% | 2749 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 27,180 psi | 39% | 2415 fps | 95.6% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 37,333 psi | 54% | 2680 fps | 95.9% |
| Rottweil R 903 | <<locked>> | 80% | 53,301 psi | 77% | 2749 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 39,958 psi | 57% | 2575 fps | 97.4% |
| Rottweil R 905 | <<locked>> | 80% | 37,942 psi | 55% | 2579 fps | 98.1% |
| Rottweil R 907 | <<locked>> | 80% | 48,878 psi | 70% | 2707 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 47,834 psi | 69% | 2677 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 57,464 psi | 83% | 2776 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 46,151 psi | 66% | 2677 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 54,679 psi | 79% | 2808 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 53,200 psi | 76% | 2618 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 46,760 psi | 67% | 2628 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 37,623 psi | 54% | 2575 fps | 98% |
| Somchem S355 | <<locked>> | 80% | 53,040 psi | 76% | 2743 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 40,611 psi | 58% | 2562 fps | 96.8% |
| Somchem S365 | <<locked>> | 80% | 42,395 psi | 61% | 2648 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 38,609 psi | 55% | 2562 fps | 98.9% |
| Vihtavuori N150 | <<locked>> | 80% | 50,749 psi | 73% | 2667 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 46,775 psi | 67% | 2684 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 33,359 psi | 48% | 2441 fps | 97.3% |
| Vihtavuori N170 | <<locked>> | 98% | 51,488 psi | 74% | 2808 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 80% | 58,059 psi | 83% | 2749 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 46,253 psi | 66% | 2694 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 37,260 psi | 54% | 2575 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 36,289 psi | 52% | 2602 fps | 95.9% |
| Vihtavuori N565 | <<locked>> | 84% | 33,968 psi | 49% | 2539 fps | 95.4% |
| Vihtavuori N568 | <<locked>> | 92% | 38,783 psi | 56% | 2694 fps | 95.7% |
| Vihtavuori N570 | <<locked>> | 98% | 45,237 psi | 65% | 2864 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 45,832 psi | 66% | 2641 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 48,109 psi | 69% | 2759 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 29,559 psi | 42% | 2539 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 35,186 psi | 51% | 2493 fps | 97.2% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 96 powders for 37 XC loaded with the .375 | 300gr | A-Square MONO RN. Vihtavuori N560 delivers the highest muzzle velocity at 3,064 fps; across all powders the maximum-charge window runs from 1,759 fps to 3,064 fps. ADI AR 2217 gives the best case fill at 100 %, and 96 of the 96 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (480 MPa), the top charges use 53–90 %, leaving at least 10 % headroom. The 300.0 gr projectile in 0.375" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-25 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. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.