Load Specifications
Load data in caliber .458 Win.Mag. with .458 | 576gr | ACME SoCom bullet and 95 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon CFE223, Alliant Power Pro 1200-R and Alliant Power Pro 2000-MR.
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 1680 | <<locked>> | 84% | 56,159 psi | 90% | 1837 fps | 100% |
| Accurate 2015 | <<locked>> | 96% | 54,302 psi | 87% | 1880 fps | 100% |
| Accurate 2200 | <<locked>> | 86% | 53,200 psi | 85% | 1926 fps | 99.1% |
| Accurate 2230 | <<locked>> | 86% | 53,243 psi | 85% | 1932 fps | 99.3% |
| Accurate 2460 | <<locked>> | 92% | 52,953 psi | 85% | 1906 fps | 100% |
| Accurate 2495ᴾ | <<locked>> | 100% | 48,791 psi | 78% | 1886 fps | 100% |
| Accurate 2520 | <<locked>> | 96% | 53,882 psi | 86% | 1946 fps | 100% |
| Accurate 4064ᴾ | <<locked>> | 100% | 45,339 psi | 73% | 1880 fps | 100% |
| Accurate LT-30 | <<locked>> | 88% | 53,824 psi | 86% | 1824 fps | 100% |
| Accurate LT-32 | <<locked>> | 88% | 54,317 psi | 87% | 1841 fps | 100% |
| ADI AR 2206H | <<locked>> | 98% | 53,563 psi | 86% | 1952 fps | 99.6% |
| ADI AR 2207 | <<locked>> | 86% | 54,215 psi | 87% | 1831 fps | 100% |
| ADI AR 2208ᴾ | <<locked>> | 100% | 48,298 psi | 77% | 1877 fps | 98.6% |
| ADI AR 2219 | <<locked>> | 88% | 52,721 psi | 85% | 1909 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 96% | 53,548 psi | 86% | 1923 fps | 99.9% |
| Alliant AR-Comp | <<locked>> | 98% | 55,230 psi | 89% | 1932 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 92% | 54,723 psi | 88% | 1995 fps | 99.9% |
| Alliant Power Pro 2000-MRᴾ | <<locked>> | 100% | 53,403 psi | 86% | 2028 fps | 99.2% |
| Alliant Reloder- TS 15.5ᴾ | <<locked>> | 100% | 46,021 psi | 74% | 1890 fps | 99.5% |
| Alliant Reloder-10x | <<locked>> | 92% | 55,201 psi | 89% | 1890 fps | 100% |
| Alliant Reloder-15ᴾ | <<locked>> | 100% | 50,459 psi | 81% | 1939 fps | 99.1% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 40,857 psi | 66% | 1883 fps | 98.3% |
| Alliant Reloder-7 | <<locked>> | 86% | 55,521 psi | 89% | 1847 fps | 100% |
| Baschieri & Pellagri 106 | <<locked>> | 90% | 55,535 psi | 89% | 1860 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 98% | 53,388 psi | 86% | 1965 fps | 99% |
| Bofors RP3ᴾ | <<locked>> | 100% | 45,310 psi | 73% | 1893 fps | 99.5% |
| Hodgdon Benchmark | <<locked>> | 96% | 56,333 psi | 90% | 1913 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 98% | 54,766 psi | 88% | 1982 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 94% | 53,330 psi | 86% | 2011 fps | 99.4% |
| Hodgdon H322 | <<locked>> | 92% | 54,592 psi | 88% | 1926 fps | 100% |
| Hodgdon H335 | <<locked>> | 92% | 55,651 psi | 89% | 1949 fps | 100% |
| Hodgdon H380ᴾ | <<locked>> | 100% | 47,848 psi | 77% | 1903 fps | 97.7% |
| Hodgdon H4198 | <<locked>> | 86% | 55,898 psi | 90% | 1854 fps | 100% |
| Hodgdon H4895 | <<locked>> | 98% | 53,969 psi | 87% | 1959 fps | 99.8% |
| Hodgdon LEVERevolutionᴾ | <<locked>> | 100% | 51,880 psi | 83% | 1978 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 33,214 psi | 53% | 1089 fps | 100% |
| Hodgdon VARGETᴾ | <<locked>> | 100% | 56,086 psi | 90% | 1962 fps | 99.9% |
| IMR 3031ᴾ | <<locked>> | 100% | 55,796 psi | 89% | 1975 fps | 100% |
| IMR 4064ᴾ | <<locked>> | 100% | 50,807 psi | 81% | 1900 fps | 99.1% |
| IMR 4166 Enduronᴾ | <<locked>> | 100% | 56,260 psi | 90% | 1923 fps | 96.6% |
| IMR 4198 | <<locked>> | 90% | 53,606 psi | 86% | 1834 fps | 100% |
| IMR 4227 | <<locked>> | 82% | 55,825 psi | 90% | 1798 fps | 100% |
| IMR 4895ᴾ | <<locked>> | 100% | 51,677 psi | 83% | 1962 fps | 99.6% |
| IMR 8208 XBR | <<locked>> | 96% | 53,548 psi | 86% | 1923 fps | 99.9% |
| Lovex D073.4 | <<locked>> | 86% | 53,795 psi | 86% | 1916 fps | 100% |
| Lovex D073.5 | <<locked>> | 92% | 53,040 psi | 85% | 1916 fps | 100% |
| Lovex D073.6ᴾ | <<locked>> | 100% | 54,940 psi | 88% | 1965 fps | 100% |
| Lovex S053 | <<locked>> | 82% | 54,302 psi | 87% | 1755 fps | 100% |
| Lovex S060 | <<locked>> | 98% | 55,201 psi | 89% | 1903 fps | 99.6% |
| Lovex S062ᴾ | <<locked>> | 100% | 49,211 psi | 79% | 1893 fps | 99.8% |
| Norma 200 | <<locked>> | 88% | 54,766 psi | 88% | 1870 fps | 100% |
| Norma 201ᴾ | <<locked>> | 100% | 55,317 psi | 89% | 1942 fps | 100% |
| Norma 202ᴾ | <<locked>> | 100% | 55,637 psi | 89% | 1949 fps | 100% |
| Norma 203Bᴾ | <<locked>> | 100% | 49,458 psi | 79% | 1929 fps | 99.3% |
| Ramshot Big Gameᴾ | <<locked>> | 100% | 50,125 psi | 80% | 1949 fps | 99.2% |
| Ramshot TAC | <<locked>> | 96% | 54,447 psi | 87% | 1936 fps | 98% |
| Ramshot Wild Boar | <<locked>> | 98% | 56,405 psi | 90% | 1985 fps | 99.7% |
| Ramshot X-Terminator | <<locked>> | 94% | 55,390 psi | 89% | 1929 fps | 99.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 33,127 psi | 53% | 1115 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 82% | 55,941 psi | 90% | 1827 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 92% | 53,577 psi | 86% | 1916 fps | 100% |
| ReloadSwiss RS 50ᴾ | <<locked>> | 100% | 49,182 psi | 79% | 1890 fps | 96.1% |
| ReloadSwiss RS 52ᴾ | <<locked>> | 100% | 53,563 psi | 86% | 2021 fps | 99.4% |
| ReloadSwiss RS 60ᴾ | <<locked>> | 100% | 43,874 psi | 70% | 1932 fps | 100% |
| Rottweil R 901 | <<locked>> | 98% | 55,927 psi | 90% | 1926 fps | 100% |
| Rottweil R 902ᴾ | <<locked>> | 100% | 52,127 psi | 84% | 1906 fps | 99.9% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 42,032 psi | 67% | 1847 fps | 98.9% |
| Shooters World AR Plus | <<locked>> | 86% | 53,795 psi | 86% | 1916 fps | 100% |
| Shooters World Match Rifleᴾ | <<locked>> | 100% | 54,940 psi | 88% | 1965 fps | 100% |
| Shooters World Precisionᴾ | <<locked>> | 100% | 49,211 psi | 79% | 1893 fps | 99.8% |
| Shooters World Tactical Rifle | <<locked>> | 90% | 54,273 psi | 87% | 1896 fps | 99.9% |
| SNPE Vectan BA6 1/2 | <<locked>> | 86% | 54,940 psi | 88% | 1647 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 88% | 52,968 psi | 85% | 1919 fps | 100% |
| SNPE Vectan SP 11ᴾ | <<locked>> | 100% | 45,092 psi | 72% | 1900 fps | 98.6% |
| SNPE Vectan SP 3 | <<locked>> | 90% | 53,156 psi | 85% | 1873 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 98% | 55,347 psi | 89% | 1952 fps | 98.5% |
| SNPE Vectan SP 9ᴾ | <<locked>> | 100% | 55,637 psi | 89% | 1969 fps | 99.7% |
| SNPE Vectan Tubal 3000 | <<locked>> | 98% | 55,550 psi | 89% | 1873 fps | 100% |
| SNPE Vectan Tubal 5000ᴾ | <<locked>> | 100% | 47,718 psi | 77% | 1811 fps | 100% |
| Somchem S321 | <<locked>> | 94% | 54,679 psi | 88% | 1955 fps | 100% |
| Somchem S335 | <<locked>> | 98% | 53,606 psi | 86% | 1873 fps | 100% |
| Somchem S341 | <<locked>> | 98% | 54,723 psi | 88% | 1949 fps | 99.6% |
| Somchem S355ᴾ | <<locked>> | 100% | 43,627 psi | 70% | 1854 fps | 98.9% |
| Somchem S365ᴾ | <<locked>> | 100% | 30,937 psi | 50% | 1732 fps | 96.9% |
| Vihtavuori N120 | <<locked>> | 86% | 54,244 psi | 87% | 1795 fps | 100% |
| Vihtavuori N130 | <<locked>> | 94% | 55,405 psi | 89% | 1854 fps | 100% |
| Vihtavuori N133 | <<locked>> | 98% | 55,085 psi | 88% | 1864 fps | 100% |
| Vihtavuori N135ᴾ | <<locked>> | 100% | 50,372 psi | 81% | 1883 fps | 100% |
| Vihtavuori N140ᴾ | <<locked>> | 100% | 52,866 psi | 85% | 1903 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 42,032 psi | 67% | 1811 fps | 99.5% |
| Vihtavuori N530 | <<locked>> | 96% | 54,273 psi | 87% | 1926 fps | 100% |
| Vihtavuori N540ᴾ | <<locked>> | 100% | 50,749 psi | 81% | 1903 fps | 100% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 38,870 psi | 62% | 1772 fps | 97.6% |
| Winchester 748 | <<locked>> | 98% | 55,999 psi | 90% | 1991 fps | 100% |
| Winchester StaBALL Matchᴾ | <<locked>> | 100% | 54,897 psi | 88% | 1975 fps | 99.9% |
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 1680 | <<locked>> | 80% | 49,298 psi | 79% | 1775 fps | 100% |
| Accurate 2015 | <<locked>> | 80% | 32,605 psi | 52% | 1637 fps | 100% |
| Accurate 2200 | <<locked>> | 80% | 43,482 psi | 70% | 1811 fps | 97.7% |
| Accurate 2230 | <<locked>> | 80% | 42,714 psi | 68% | 1814 fps | 98% |
| Accurate 2460 | <<locked>> | 80% | 34,867 psi | 56% | 1699 fps | 99.4% |
| Accurate 2495 | <<locked>> | 80% | 24,178 psi | 39% | 1558 fps | 99.4% |
| Accurate 2520 | <<locked>> | 80% | 30,458 psi | 49% | 1663 fps | 98.4% |
| Accurate 4064 | <<locked>> | 80% | 23,047 psi | 37% | 1545 fps | 97.1% |
| Accurate LT-30 | <<locked>> | 80% | 41,959 psi | 67% | 1699 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 42,337 psi | 68% | 1713 fps | 99.8% |
| ADI AR 2206H | <<locked>> | 82% | 32,068 psi | 51% | 1670 fps | 95.7% |
| ADI AR 2207 | <<locked>> | 80% | 45,150 psi | 72% | 1745 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 33,185 psi | 53% | 1673 fps | 95% |
| ADI AR 2219 | <<locked>> | 80% | 40,045 psi | 64% | 1772 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 32,068 psi | 51% | 1650 fps | 97% |
| Alliant AR-Comp | <<locked>> | 80% | 30,139 psi | 48% | 1657 fps | 100% |
| Alliant Power Pro 1200-R | 52.5 gr | 80% | 36,521 psi | 59% | 1772 fps | 97.8% |
| Alliant Power Pro 2000-MR | 61.5 gr | 88% | 35,549 psi | 57% | 1785 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 27,412 psi | 44% | 1614 fps | 95.1% |
| Alliant Reloder-10x | <<locked>> | 80% | 37,768 psi | 61% | 1709 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 32,010 psi | 51% | 1690 fps | 95.1% |
| Alliant Reloder-17 | <<locked>> | 92% | 31,372 psi | 50% | 1726 fps | 95.2% |
| Alliant Reloder-7 | <<locked>> | 80% | 46,050 psi | 74% | 1755 fps | 100% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 40,306 psi | 65% | 1706 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 35,636 psi | 57% | 1742 fps | 95.4% |
| Bofors RP3 | <<locked>> | 86% | 27,804 psi | 45% | 1640 fps | 95.5% |
| Hodgdon Benchmark | <<locked>> | 80% | 34,505 psi | 55% | 1654 fps | 98.2% |
| Hodgdon BL-C2 | <<locked>> | 80% | 29,138 psi | 47% | 1654 fps | 96.9% |
| Hodgdon CFE223 | 57.2 gr | 80% | 32,808 psi | 53% | 1732 fps | 95.1% |
| Hodgdon H322 | <<locked>> | 80% | 36,477 psi | 58% | 1726 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 36,811 psi | 59% | 1742 fps | 99.7% |
| Hodgdon H380 | <<locked>> | 92% | 36,550 psi | 59% | 1759 fps | 95% |
| Hodgdon H4198 | <<locked>> | 80% | 46,383 psi | 74% | 1759 fps | 100% |
| Hodgdon H4895 | <<locked>> | 80% | 30,139 psi | 48% | 1644 fps | 95.7% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 28,645 psi | 46% | 1650 fps | 95.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 24,453 psi | 39% | 971 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 29,486 psi | 47% | 1614 fps | 95.2% |
| IMR 3031 | <<locked>> | 80% | 28,660 psi | 46% | 1647 fps | 99.6% |
| IMR 4064 | <<locked>> | 86% | 32,663 psi | 52% | 1663 fps | 95.2% |
| IMR 4166 Enduron | <<locked>> | 96% | 49,443 psi | 79% | 1850 fps | 95.3% |
| IMR 4198 | <<locked>> | 80% | 39,740 psi | 64% | 1693 fps | 100% |
| IMR 4227 | <<locked>> | 80% | 52,547 psi | 84% | 1768 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 30,589 psi | 49% | 1677 fps | 95.3% |
| IMR 8208 XBR | <<locked>> | 80% | 32,068 psi | 51% | 1650 fps | 97% |
| Lovex D073.4 | <<locked>> | 80% | 43,366 psi | 70% | 1808 fps | 99.9% |
| Lovex D073.5 | <<locked>> | 80% | 34,606 psi | 55% | 1699 fps | 98.6% |
| Lovex D073.6 | <<locked>> | 80% | 27,253 psi | 44% | 1617 fps | 97.4% |
| Lovex S053 | <<locked>> | 80% | 51,430 psi | 82% | 1729 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 31,778 psi | 51% | 1608 fps | 95.4% |
| Lovex S062 | <<locked>> | 82% | 27,659 psi | 44% | 1591 fps | 95.7% |
| Norma 200 | <<locked>> | 80% | 42,264 psi | 68% | 1749 fps | 100% |
| Norma 201 | <<locked>> | 80% | 29,037 psi | 47% | 1604 fps | 96.2% |
| Norma 202 | <<locked>> | 80% | 29,080 psi | 47% | 1621 fps | 98.5% |
| Norma 203B | <<locked>> | 86% | 31,285 psi | 50% | 1683 fps | 95.5% |
| Ramshot Big Game | <<locked>> | 88% | 33,489 psi | 54% | 1726 fps | 95.7% |
| Ramshot TAC | <<locked>> | 88% | 41,800 psi | 67% | 1791 fps | 95.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 30,632 psi | 49% | 1657 fps | 95% |
| Ramshot X-Terminator | <<locked>> | 80% | 34,925 psi | 56% | 1680 fps | 96.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 24,308 psi | 39% | 994 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 80% | 52,779 psi | 85% | 1801 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 36,129 psi | 58% | 1709 fps | 99.1% |
| ReloadSwiss RS 50 | <<locked>> | 98% | 46,195 psi | 74% | 1857 fps | 95.5% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 33,199 psi | 53% | 1752 fps | 95.4% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 25,889 psi | 42% | 1617 fps | 95.2% |
| Rottweil R 901 | <<locked>> | 80% | 32,242 psi | 52% | 1644 fps | 99% |
| Rottweil R 902 | <<locked>> | 80% | 27,586 psi | 44% | 1572 fps | 95.5% |
| Rottweil R 903 | <<locked>> | 88% | 27,905 psi | 45% | 1637 fps | 95.1% |
| Shooters World AR Plus | <<locked>> | 80% | 43,366 psi | 70% | 1808 fps | 99.9% |
| Shooters World Match Rifle | <<locked>> | 80% | 27,253 psi | 44% | 1617 fps | 97.4% |
| Shooters World Precision | <<locked>> | 82% | 27,659 psi | 44% | 1591 fps | 95.7% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 38,319 psi | 61% | 1719 fps | 98.2% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 46,992 psi | 75% | 1578 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 40,408 psi | 65% | 1778 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 90% | 32,576 psi | 52% | 1716 fps | 95.5% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 38,696 psi | 62% | 1716 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 38,740 psi | 62% | 1762 fps | 95.4% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 30,821 psi | 49% | 1650 fps | 95.1% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 31,386 psi | 50% | 1594 fps | 98.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 25,222 psi | 40% | 1503 fps | 98.1% |
| Somchem S321 | <<locked>> | 80% | 33,692 psi | 54% | 1699 fps | 97.9% |
| Somchem S335 | <<locked>> | 80% | 30,501 psi | 49% | 1598 fps | 99.3% |
| Somchem S341 | <<locked>> | 82% | 31,488 psi | 50% | 1657 fps | 95.2% |
| Somchem S355 | <<locked>> | 88% | 29,602 psi | 47% | 1650 fps | 95.5% |
| Somchem S365 | <<locked>> | 96% | 27,151 psi | 44% | 1654 fps | 95.1% |
| Vihtavuori N120 | <<locked>> | 80% | 45,310 psi | 73% | 1713 fps | 100% |
| Vihtavuori N130 | <<locked>> | 80% | 35,984 psi | 58% | 1650 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 31,372 psi | 50% | 1598 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 26,107 psi | 42% | 1575 fps | 99.7% |
| Vihtavuori N140 | <<locked>> | 80% | 27,499 psi | 44% | 1578 fps | 98.3% |
| Vihtavuori N150 | <<locked>> | 86% | 26,426 psi | 42% | 1575 fps | 95.6% |
| Vihtavuori N530 | <<locked>> | 80% | 31,720 psi | 51% | 1644 fps | 97% |
| Vihtavuori N540 | <<locked>> | 80% | 26,179 psi | 42% | 1572 fps | 97.4% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 31,908 psi | 51% | 1663 fps | 95.3% |
| Winchester 748 | <<locked>> | 80% | 30,269 psi | 49% | 1667 fps | 97.5% |
| Winchester StaBALL Match | <<locked>> | 82% | 29,704 psi | 48% | 1647 fps | 95.4% |
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 .458 Win.Mag. loaded with the .458 | 576gr | ACME SoCom. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,028 fps; across all powders the maximum-charge window runs from 1,089 fps to 2,028 fps. Accurate 2495 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 (430 MPa), the top charges use 50–90 %, leaving at least 10 % headroom. Accurate 2495, Accurate 4064, ADI AR 2208 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. Hodgdon CFE223, Alliant Power Pro 1200-R, Alliant Power Pro 2000-MR rank at the top here: for .458 Win.Mag. with the .458 | 576gr | ACME SoCom they combine a high case fill with complete burn and sit in the upper velocity band. Hodgdon TrailBoss, ReloadSwiss RS 14 stay subsonic at start load. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.