Load Specifications
Bullet:.323 | 170gr | Hornady SST
Bullet Manufacturer:Hornady
Bullet Weight:170 gr
Bullet Diameter:0.323"
Bullet Length:<<locked>>
Caliber:8 x 57 IRS load data
Case Length (l3):2.244"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:64 Grains of Water
Primer Size:Large Rifle (LR)
Barrel Length:23.62"
Max. allowed Pressure:47,862 psi
Recommended Twist Rate:1:14.0
Load data in caliber 8 x 57 IRS with .323 | 170gr | Hornady SST bullet and 105 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 60, Hodgdon LEVERevolution and IMR 3031.
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: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 84% | 41,611 psi | 87% | 2520 fps | 100% |
| Accurate 2015 | <<locked>> | 84% | 42,061 psi | 88% | 2533 fps | 100% |
| Accurate 2460 | <<locked>> | 82% | 42,438 psi | 89% | 2566 fps | 99.2% |
| Accurate 2460 | <<locked>> | 82% | 42,583 psi | 89% | 2569 fps | 99.2% |
| Accurate 2495 | <<locked>> | 92% | 43,221 psi | 90% | 2608 fps | 100% |
| Accurate 2495 | <<locked>> | 90% | 41,031 psi | 86% | 2572 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 42,975 psi | 90% | 2615 fps | 99% |
| Accurate 2520 | <<locked>> | 84% | 40,625 psi | 85% | 2572 fps | 98.7% |
| Accurate 4064 | <<locked>> | 94% | 43,265 psi | 90% | 2638 fps | 99.7% |
| Accurate 4064 | <<locked>> | 92% | 40,901 psi | 85% | 2598 fps | 99.4% |
| ADI AR 2206H | <<locked>> | 86% | 41,104 psi | 86% | 2572 fps | 95.8% |
| ADI Benchmark 8208 | <<locked>> | 86% | 42,960 psi | 90% | 2579 fps | 97.6% |
| ADI Benchmark 8208 | <<locked>> | 84% | 40,712 psi | 85% | 2539 fps | 97.1% |
| Alliant AR-Comp | <<locked>> | 86% | 41,234 psi | 86% | 2589 fps | 100% |
| Alliant AR-Comp | <<locked>> | 86% | 41,713 psi | 87% | 2602 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 42,888 psi | 90% | 2628 fps | 97.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 43,294 psi | 90% | 2638 fps | 97.5% |
| Alliant Reloder-17 | <<locked>> | 98% | 42,873 psi | 90% | 2697 fps | 96.4% |
| Bofors RP3 | <<locked>> | 94% | 42,279 psi | 88% | 2628 fps | 97.3% |
| Bofors RP3 | <<locked>> | 94% | 42,656 psi | 89% | 2641 fps | 97.4% |
| Hodgdon Benchmark | <<locked>> | 84% | 42,859 psi | 90% | 2536 fps | 98.1% |
| Hodgdon Benchmark | <<locked>> | 84% | 43,047 psi | 90% | 2543 fps | 98.1% |
| Hodgdon BL-C2 | <<locked>> | 86% | 40,770 psi | 85% | 2592 fps | 97.7% |
| Hodgdon BL-C2 | <<locked>> | 86% | 41,162 psi | 86% | 2602 fps | 97.8% |
| Hodgdon H322 | <<locked>> | 82% | 43,047 psi | 90% | 2595 fps | 99.8% |
| Hodgdon H4895 | <<locked>> | 86% | 40,915 psi | 85% | 2572 fps | 96.4% |
| Hodgdon H4895 | <<locked>> | 86% | 41,321 psi | 86% | 2585 fps | 96.6% |
| Hodgdon LEVERevolution | <<locked>> | 90% | 41,771 psi | 87% | 2641 fps | 97.1% |
| Hodgdon LEVERevolution | <<locked>> | 90% | 42,105 psi | 88% | 2651 fps | 97.2% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 33,895 psi | 71% | 1654 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,084 psi | 71% | 1660 fps | 100% |
| Hodgdon VARGET | <<locked>> | 88% | 42,148 psi | 88% | 2579 fps | 96.6% |
| Hodgdon VARGET | <<locked>> | 88% | 42,525 psi | 89% | 2592 fps | 96.8% |
| IMR 3031 | <<locked>> | 88% | 42,032 psi | 88% | 2631 fps | 100% |
| IMR 3031 | <<locked>> | 88% | 42,496 psi | 89% | 2644 fps | 100% |
| IMR 4895 | <<locked>> | 90% | 41,843 psi | 87% | 2618 fps | 96.1% |
| IMR 4895 | <<locked>> | 90% | 42,264 psi | 88% | 2631 fps | 96.3% |
| IMR 8208 XBR | <<locked>> | 86% | 42,960 psi | 90% | 2579 fps | 97.6% |
| IMR 8208 XBR | <<locked>> | 84% | 40,712 psi | 85% | 2539 fps | 97.1% |
| Lovex D073.5 | <<locked>> | 82% | 42,235 psi | 88% | 2566 fps | 98.3% |
| Lovex D073.5 | <<locked>> | 82% | 42,656 psi | 89% | 2575 fps | 98.4% |
| Lovex D073.6 | <<locked>> | 88% | 41,249 psi | 86% | 2592 fps | 98.7% |
| Lovex D073.6 | <<locked>> | 88% | 41,684 psi | 87% | 2605 fps | 98.8% |
| Lovex S060 | <<locked>> | 86% | 41,930 psi | 88% | 2513 fps | 96% |
| Lovex S060 | <<locked>> | 86% | 42,061 psi | 88% | 2520 fps | 96.1% |
| Lovex S062 | <<locked>> | 92% | 43,076 psi | 90% | 2598 fps | 97.7% |
| Lovex S062 | <<locked>> | 90% | 40,683 psi | 85% | 2556 fps | 97.2% |
| Norma 201 | <<locked>> | 88% | 42,496 psi | 89% | 2572 fps | 97.5% |
| Norma 201 | <<locked>> | 88% | 42,641 psi | 89% | 2579 fps | 97.6% |
| Norma 202 | <<locked>> | 88% | 42,366 psi | 89% | 2589 fps | 99.3% |
| Norma 202 | <<locked>> | 88% | 42,786 psi | 89% | 2598 fps | 99.4% |
| Norma 203B | <<locked>> | 92% | 42,859 psi | 90% | 2628 fps | 96.3% |
| Norma 203B | <<locked>> | 92% | 43,250 psi | 90% | 2638 fps | 96.5% |
| Ramshot Big Game | <<locked>> | 92% | 42,888 psi | 90% | 2641 fps | 95.9% |
| Ramshot Big Game | <<locked>> | 92% | 43,178 psi | 90% | 2651 fps | 96.1% |
| Ramshot Wild Boar | <<locked>> | 86% | 42,047 psi | 88% | 2595 fps | 95.9% |
| Ramshot Wild Boar | <<locked>> | 86% | 42,409 psi | 89% | 2605 fps | 96.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,214 psi | 71% | 1696 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,142 psi | 71% | 1699 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 42,569 psi | 89% | 2572 fps | 98.7% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 43,018 psi | 90% | 2582 fps | 98.8% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 42,946 psi | 90% | 2713 fps | 98.8% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 40,553 psi | 85% | 2667 fps | 98.3% |
| Rottweil R 901 | <<locked>> | 84% | 41,191 psi | 86% | 2530 fps | 99% |
| Rottweil R 901 | <<locked>> | 84% | 41,640 psi | 87% | 2539 fps | 99.1% |
| Rottweil R 902 | <<locked>> | 90% | 42,670 psi | 89% | 2566 fps | 97.6% |
| Rottweil R 902 | <<locked>> | 90% | 43,062 psi | 90% | 2579 fps | 97.7% |
| Rottweil R 903 | <<locked>> | 96% | 42,177 psi | 88% | 2618 fps | 96.9% |
| Rottweil R 903 | <<locked>> | 96% | 42,540 psi | 89% | 2628 fps | 97.1% |
| Shooters World Match Rifle | <<locked>> | 88% | 41,249 psi | 86% | 2592 fps | 98.7% |
| Shooters World Match Rifle | <<locked>> | 88% | 41,684 psi | 87% | 2605 fps | 98.8% |
| Shooters World Precision | <<locked>> | 92% | 43,076 psi | 90% | 2598 fps | 97.7% |
| Shooters World Precision | <<locked>> | 90% | 40,683 psi | 85% | 2556 fps | 97.2% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 41,785 psi | 87% | 2582 fps | 95.9% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 42,163 psi | 88% | 2592 fps | 96.1% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 41,916 psi | 88% | 2497 fps | 99.2% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 42,366 psi | 89% | 2507 fps | 99.3% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 41,292 psi | 86% | 2497 fps | 99.7% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 41,423 psi | 87% | 2503 fps | 99.7% |
| Somchem S321 | <<locked>> | 82% | 40,480 psi | 85% | 2556 fps | 97.3% |
| Somchem S321 | <<locked>> | 82% | 40,814 psi | 85% | 2562 fps | 97.4% |
| Somchem S335 | <<locked>> | 86% | 41,162 psi | 86% | 2500 fps | 99.5% |
| Somchem S335 | <<locked>> | 86% | 41,539 psi | 87% | 2510 fps | 99.6% |
| Somchem S341 | <<locked>> | 88% | 43,149 psi | 90% | 2595 fps | 96.1% |
| Somchem S355 | <<locked>> | 96% | 43,294 psi | 90% | 2625 fps | 96.9% |
| Somchem S355 | <<locked>> | 94% | 41,191 psi | 86% | 2589 fps | 96.4% |
| Vihtavuori N130 | <<locked>> | 82% | 42,134 psi | 88% | 2490 fps | 100% |
| Vihtavuori N130 | <<locked>> | 82% | 42,583 psi | 89% | 2500 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 41,800 psi | 87% | 2500 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 42,235 psi | 88% | 2510 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 41,075 psi | 86% | 2562 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 41,553 psi | 87% | 2572 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 42,627 psi | 89% | 2569 fps | 99.5% |
| Vihtavuori N140 | <<locked>> | 90% | 43,062 psi | 90% | 2579 fps | 99.6% |
| Vihtavuori N150 | <<locked>> | 96% | 41,669 psi | 87% | 2566 fps | 97.8% |
| Vihtavuori N150 | <<locked>> | 96% | 42,018 psi | 88% | 2579 fps | 98% |
| Vihtavuori N530 | <<locked>> | 86% | 43,033 psi | 90% | 2575 fps | 97.7% |
| Vihtavuori N530 | <<locked>> | 84% | 40,654 psi | 85% | 2536 fps | 97.2% |
| Vihtavuori N540 | <<locked>> | 90% | 41,162 psi | 86% | 2559 fps | 99% |
| Vihtavuori N540 | <<locked>> | 90% | 41,524 psi | 87% | 2569 fps | 99.1% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 41,075 psi | 86% | 2552 fps | 96% |
| Winchester 748 | <<locked>> | 86% | 41,684 psi | 87% | 2615 fps | 98.2% |
| Winchester 748 | <<locked>> | 86% | 41,843 psi | 87% | 2621 fps | 98.3% |
| Winchester StaBALL Match | <<locked>> | 88% | 40,799 psi | 85% | 2582 fps | 96.4% |
| Winchester StaBALL Match | <<locked>> | 88% | 41,162 psi | 86% | 2592 fps | 96.5% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 36,767 psi | 77% | 2428 fps | 99.8% |
| Accurate 2015 | <<locked>> | 80% | 36,999 psi | 77% | 2438 fps | 99.8% |
| Accurate 2460 | <<locked>> | 80% | 39,711 psi | 83% | 2513 fps | 98.7% |
| Accurate 2460 | <<locked>> | 80% | 39,885 psi | 83% | 2520 fps | 98.8% |
| Accurate 2495 | <<locked>> | 80% | 29,138 psi | 61% | 2320 fps | 98.8% |
| Accurate 2495 | <<locked>> | 80% | 29,370 psi | 61% | 2326 fps | 98.9% |
| Accurate 2520 | <<locked>> | 80% | 34,867 psi | 73% | 2451 fps | 97.3% |
| Accurate 2520 | <<locked>> | 80% | 35,259 psi | 74% | 2464 fps | 97.4% |
| Accurate 4064 | <<locked>> | 80% | 27,615 psi | 58% | 2290 fps | 95.9% |
| Accurate 4064 | <<locked>> | 80% | 27,833 psi | 58% | 2300 fps | 96% |
| ADI AR 2206H | <<locked>> | 84% | 38,493 psi | 80% | 2520 fps | 95% |
| ADI Benchmark 8208 | <<locked>> | 80% | 35,563 psi | 74% | 2428 fps | 95.5% |
| ADI Benchmark 8208 | <<locked>> | 80% | 35,940 psi | 75% | 2438 fps | 95.6% |
| Alliant AR-Comp | <<locked>> | 80% | 33,779 psi | 71% | 2448 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 34,229 psi | 72% | 2461 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 35,317 psi | 74% | 2474 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 35,665 psi | 75% | 2484 fps | 95.3% |
| Alliant Reloder-17 | <<locked>> | 96% | 40,190 psi | 84% | 2638 fps | 95.5% |
| Bofors RP3 | <<locked>> | 90% | 37,072 psi | 77% | 2526 fps | 95.8% |
| Bofors RP3 | <<locked>> | 88% | 34,998 psi | 73% | 2484 fps | 95.1% |
| Hodgdon Benchmark | <<locked>> | 80% | 37,942 psi | 79% | 2438 fps | 96.9% |
| Hodgdon Benchmark | <<locked>> | 80% | 38,087 psi | 80% | 2444 fps | 97% |
| Hodgdon BL-C2 | <<locked>> | 80% | 33,199 psi | 69% | 2428 fps | 95.4% |
| Hodgdon BL-C2 | <<locked>> | 80% | 33,576 psi | 70% | 2441 fps | 95.6% |
| Hodgdon H322 | <<locked>> | 80% | 40,437 psi | 84% | 2546 fps | 99.6% |
| Hodgdon H4895 | <<locked>> | 84% | 38,566 psi | 81% | 2523 fps | 95.7% |
| Hodgdon H4895 | <<locked>> | 82% | 36,521 psi | 76% | 2484 fps | 95.1% |
| Hodgdon LEVERevolution | 48.1 gr | 86% | 36,724 psi | 77% | 2533 fps | 95.5% |
| Hodgdon LEVERevolution | 48.1 gr | 86% | 36,825 psi | 77% | 2536 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,077 psi | 52% | 1476 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,063 psi | 52% | 1480 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 37,173 psi | 78% | 2477 fps | 95.1% |
| Hodgdon VARGET | <<locked>> | 84% | 37,536 psi | 78% | 2490 fps | 95.3% |
| IMR 3031 | 41.4 gr | 80% | 32,372 psi | 68% | 2431 fps | 98.8% |
| IMR 3031 | 41.4 gr | 80% | 32,605 psi | 68% | 2438 fps | 98.9% |
| IMR 4895 | <<locked>> | 88% | 39,407 psi | 82% | 2569 fps | 95.4% |
| IMR 4895 | <<locked>> | 88% | 39,827 psi | 83% | 2582 fps | 95.6% |
| IMR 8208 XBR | <<locked>> | 80% | 35,563 psi | 74% | 2428 fps | 95.5% |
| IMR 8208 XBR | <<locked>> | 80% | 35,940 psi | 75% | 2438 fps | 95.6% |
| Lovex D073.5 | <<locked>> | 80% | 39,305 psi | 82% | 2507 fps | 97.6% |
| Lovex D073.5 | <<locked>> | 80% | 39,726 psi | 83% | 2520 fps | 97.8% |
| Lovex D073.6 | <<locked>> | 80% | 31,430 psi | 66% | 2382 fps | 96.1% |
| Lovex D073.6 | <<locked>> | 80% | 31,792 psi | 66% | 2395 fps | 96.3% |
| Lovex S060 | <<locked>> | 84% | 39,334 psi | 82% | 2461 fps | 95.2% |
| Lovex S060 | <<locked>> | 84% | 39,711 psi | 83% | 2474 fps | 95.4% |
| Lovex S062 | <<locked>> | 86% | 35,766 psi | 75% | 2448 fps | 95.7% |
| Lovex S062 | <<locked>> | 84% | 33,881 psi | 71% | 2408 fps | 95.1% |
| Norma 201 | <<locked>> | 82% | 35,114 psi | 73% | 2418 fps | 95.4% |
| Norma 201 | <<locked>> | 82% | 35,505 psi | 74% | 2431 fps | 95.6% |
| Norma 202 | <<locked>> | 80% | 32,793 psi | 69% | 2388 fps | 97.3% |
| Norma 202 | <<locked>> | 80% | 33,199 psi | 69% | 2398 fps | 97.5% |
| Norma 203B | <<locked>> | 90% | 40,118 psi | 84% | 2575 fps | 95.5% |
| Norma 203B | <<locked>> | 88% | 38,189 psi | 80% | 2539 fps | 95% |
| Ramshot Big Game | <<locked>> | 90% | 40,205 psi | 84% | 2589 fps | 95.1% |
| Ramshot Big Game | <<locked>> | 90% | 40,567 psi | 85% | 2598 fps | 95.3% |
| Ramshot Wild Boar | <<locked>> | 84% | 39,218 psi | 82% | 2539 fps | 95.1% |
| Ramshot Wild Boar | <<locked>> | 84% | 39,595 psi | 83% | 2549 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,222 psi | 53% | 1512 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,222 psi | 53% | 1516 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 40,118 psi | 84% | 2523 fps | 98.2% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 40,321 psi | 84% | 2530 fps | 98.3% |
| ReloadSwiss RS 60 | 48.3 gr | 88% | 33,301 psi | 70% | 2484 fps | 95.5% |
| ReloadSwiss RS 60 | 49.5 gr | 88% | 33,576 psi | 70% | 2497 fps | 95.7% |
| Rottweil R 901 | <<locked>> | 80% | 36,593 psi | 76% | 2434 fps | 98% |
| Rottweil R 901 | <<locked>> | 80% | 36,782 psi | 77% | 2441 fps | 98.1% |
| Rottweil R 902 | <<locked>> | 84% | 35,665 psi | 75% | 2425 fps | 95.6% |
| Rottweil R 902 | <<locked>> | 82% | 33,823 psi | 71% | 2382 fps | 95% |
| Rottweil R 903 | <<locked>> | 92% | 36,999 psi | 77% | 2516 fps | 95.4% |
| Rottweil R 903 | <<locked>> | 92% | 37,391 psi | 78% | 2526 fps | 95.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 31,430 psi | 66% | 2382 fps | 96.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 31,792 psi | 66% | 2395 fps | 96.3% |
| Shooters World Precision | <<locked>> | 86% | 35,766 psi | 75% | 2448 fps | 95.7% |
| Shooters World Precision | <<locked>> | 84% | 33,881 psi | 71% | 2408 fps | 95.1% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 39,175 psi | 82% | 2526 fps | 95.1% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 39,566 psi | 83% | 2539 fps | 95.3% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 34,867 psi | 73% | 2356 fps | 97.8% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 35,085 psi | 73% | 2362 fps | 97.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 28,297 psi | 59% | 2218 fps | 96.8% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 28,471 psi | 59% | 2228 fps | 96.9% |
| Somchem S321 | <<locked>> | 80% | 37,927 psi | 79% | 2500 fps | 96.6% |
| Somchem S321 | <<locked>> | 80% | 38,072 psi | 80% | 2507 fps | 96.7% |
| Somchem S335 | <<locked>> | 80% | 34,301 psi | 72% | 2359 fps | 98.4% |
| Somchem S335 | <<locked>> | 80% | 34,461 psi | 72% | 2365 fps | 98.5% |
| Somchem S341 | <<locked>> | 86% | 40,422 psi | 84% | 2543 fps | 95.4% |
| Somchem S355 | <<locked>> | 92% | 38,159 psi | 80% | 2523 fps | 95.5% |
| Somchem S355 | <<locked>> | 92% | 38,551 psi | 81% | 2533 fps | 95.7% |
| Vihtavuori N130 | <<locked>> | 80% | 39,653 psi | 83% | 2444 fps | 100% |
| Vihtavuori N130 | <<locked>> | 80% | 39,856 psi | 83% | 2454 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 34,809 psi | 73% | 2365 fps | 99.5% |
| Vihtavuori N133 | <<locked>> | 80% | 35,012 psi | 73% | 2372 fps | 99.6% |
| Vihtavuori N135 | <<locked>> | 80% | 29,834 psi | 62% | 2326 fps | 98.9% |
| Vihtavuori N135 | <<locked>> | 80% | 30,066 psi | 63% | 2336 fps | 99% |
| Vihtavuori N140 | <<locked>> | 80% | 31,096 psi | 65% | 2329 fps | 97.1% |
| Vihtavuori N140 | <<locked>> | 80% | 31,256 psi | 65% | 2336 fps | 97.2% |
| Vihtavuori N150 | <<locked>> | 90% | 34,229 psi | 72% | 2418 fps | 95.8% |
| Vihtavuori N150 | <<locked>> | 88% | 32,532 psi | 68% | 2382 fps | 95.2% |
| Vihtavuori N530 | <<locked>> | 80% | 35,404 psi | 74% | 2421 fps | 95.5% |
| Vihtavuori N530 | <<locked>> | 80% | 35,549 psi | 74% | 2428 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 80% | 29,878 psi | 62% | 2313 fps | 96% |
| Vihtavuori N540 | <<locked>> | 80% | 30,037 psi | 63% | 2320 fps | 96.1% |
| Winchester 6.5 StaBALL | <<locked>> | 96% | 38,580 psi | 81% | 2500 fps | 95.1% |
| Winchester 748 | <<locked>> | 80% | 33,997 psi | 71% | 2451 fps | 96% |
| Winchester 748 | <<locked>> | 80% | 34,389 psi | 72% | 2464 fps | 96.2% |
| Winchester StaBALL Match | <<locked>> | 86% | 38,232 psi | 80% | 2530 fps | 95.6% |
| Winchester StaBALL Match | <<locked>> | 86% | 38,595 psi | 81% | 2539 fps | 95.8% |
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 160 powders for 8 x 57 IRS loaded with the .323 | 170gr | Hornady SST. ReloadSwiss RS 60 delivers the highest muzzle velocity at 2,713 fps; across all powders the maximum-charge window runs from 1,654 fps to 2,713 fps. Accurate 4350 gives the best case fill at 100 %, and 160 of the 160 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (330 MPa), the top charges use 71–90 %, leaving at least 10 % headroom. The 170.0 gr projectile in 0.323" calls for a 1:14.0 twist; slower twists will usually not stabilise this weight. Accurate 4350, Accurate 4350, Alliant Reloder-16 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. ReloadSwiss RS 60, Hodgdon LEVERevolution, IMR 3031 rank at the top here: for 8 x 57 IRS with the .323 | 170gr | Hornady SST they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 4350, Accurate 4350, Alliant Power Pro 2000-MR 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.