Load Specifications
Load data in caliber 7 x 72 R with .284 | 170gr | Sierra RN Prohunter bullet and 22 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Somchem S365, Vihtavuori N555 and Alliant Reloder-16.
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: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 4350 | <<locked>> | 88% | 34,621 psi | 85% | 2280 fps | 96.5% |
| Alliant Reloder-16 | <<locked>> | 88% | 35,273 psi | 87% | 2290 fps | 96.7% |
| Alliant Reloder-17 | <<locked>> | 84% | 34,650 psi | 85% | 2310 fps | 98.2% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 36,158 psi | 89% | 2346 fps | 98.5% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 36,535 psi | 90% | 2287 fps | 98.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,099 psi | 86% | 1499 fps | 100% |
| IMR 4831 | <<locked>> | 94% | 36,463 psi | 90% | 2300 fps | 97.1% |
| Norma URP | <<locked>> | 88% | 35,244 psi | 87% | 2283 fps | 96.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,592 psi | 88% | 1535 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 34,563 psi | 85% | 2313 fps | 99.7% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 34,519 psi | 85% | 2297 fps | 96% |
| Rottweil R 903 | <<locked>> | 82% | 34,896 psi | 86% | 2234 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 36,129 psi | 89% | 2283 fps | 98% |
| Somchem S355 | <<locked>> | 82% | 36,056 psi | 89% | 2244 fps | 98.4% |
| Somchem S365 | <<locked>> | 92% | 35,708 psi | 88% | 2336 fps | 99.4% |
| Unknown powder | <<locked>> | 86% | 35,911 psi | 88% | 2283 fps | 95.9% |
| Vihtavuori N150 | <<locked>> | 86% | 34,824 psi | 86% | 2201 fps | 99.1% |
| Vihtavuori N160 | <<locked>> | 86% | 36,013 psi | 89% | 2264 fps | 96.6% |
| Vihtavuori N550 | <<locked>> | 86% | 36,274 psi | 89% | 2300 fps | 96.6% |
| Vihtavuori N555 | <<locked>> | 98% | 36,361 psi | 90% | 2362 fps | 97.7% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 34,577 psi | 85% | 2218 fps | 98.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 32,213 psi | 79% | 2336 fps | 98% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 4350 | <<locked>> | 86% | 32,227 psi | 79% | 2228 fps | 95.6% |
| Alliant Reloder-16 | 35.7 gr | 86% | 33,272 psi | 82% | 2244 fps | 95.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 30,414 psi | 75% | 2205 fps | 96.6% |
| Alliant Reloder-23 | <<locked>> | 92% | 28,340 psi | 70% | 2156 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 28,500 psi | 70% | 2106 fps | 95.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,310 psi | 65% | 1342 fps | 100% |
| IMR 4831 | <<locked>> | 90% | 32,256 psi | 79% | 2211 fps | 95.7% |
| Norma URP | <<locked>> | 86% | 32,909 psi | 81% | 2231 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,556 psi | 65% | 1371 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 32,358 psi | 80% | 2264 fps | 99.4% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 32,300 psi | 80% | 2244 fps | 95.1% |
| Rottweil R 903 | <<locked>> | 80% | 32,808 psi | 81% | 2188 fps | 97.8% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 33,808 psi | 83% | 2234 fps | 97.3% |
| Somchem S355 | <<locked>> | 80% | 33,692 psi | 83% | 2195 fps | 97.8% |
| Somchem S365 | 33.9 gr | 80% | 24,453 psi | 60% | 2047 fps | 95.2% |
| Unknown powder | <<locked>> | 84% | 33,837 psi | 83% | 2238 fps | 95.1% |
| Vihtavuori N150 | <<locked>> | 80% | 28,732 psi | 71% | 2067 fps | 97.6% |
| Vihtavuori N160 | <<locked>> | 84% | 33,721 psi | 83% | 2215 fps | 95.7% |
| Vihtavuori N550 | <<locked>> | 82% | 31,923 psi | 79% | 2205 fps | 95% |
| Vihtavuori N555 | 38.4 gr | 92% | 30,095 psi | 74% | 2221 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 28,601 psi | 70% | 2077 fps | 95.8% |
| Winchester StaBALL HD | <<locked>> | 96% | 28,355 psi | 70% | 2221 fps | 95.6% |
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 22 powders for 7 x 72 R loaded with the .284 | 170gr | Sierra RN Prohunter. Vihtavuori N555 delivers the highest muzzle velocity at 2,362 fps; across all powders the maximum-charge window runs from 1,499 fps to 2,362 fps. Alliant Reloder-23 gives the best case fill at 100 %, and 22 of the 22 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (280 MPa), the top charges use 79–90 %, leaving at least 10 % headroom. The 170.0 gr projectile in 0.284" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Alliant Reloder-23, Hodgdon TrailBoss, ReloadSwiss RS 14 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. Somchem S365, Vihtavuori N555, Alliant Reloder-16 rank at the top here: for 7 x 72 R with the .284 | 170gr | Sierra RN Prohunter 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.