Load Specifications
Load data in caliber .257 Roberts with .257 | 52gr | Peregrine VRG-3 bullet and 61 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are IMR 3031, Alliant AR-Comp and Vihtavuori N135.
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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Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 90% | 44,701 psi | 87% | 3717 fps | 98.7% |
| Accurate 2015 | <<locked>> | 92% | 46,369 psi | 90% | 3760 fps | 99% |
| Accurate 2460 | <<locked>> | 88% | 46,412 psi | 90% | 3760 fps | 96.6% |
| Accurate 2460 | <<locked>> | 88% | 45,252 psi | 88% | 3737 fps | 96.3% |
| Accurate 2495 | <<locked>> | 96% | 43,424 psi | 84% | 3730 fps | 98.8% |
| Accurate 2495 | <<locked>> | 98% | 45,121 psi | 88% | 3773 fps | 99.1% |
| Accurate 2520 | <<locked>> | 92% | 46,093 psi | 90% | 3786 fps | 96.1% |
| Accurate 4064ᴾ | <<locked>> | 100% | 46,369 psi | 90% | 3812 fps | 97.4% |
| Accurate 4064ᴾ | <<locked>> | 100% | 44,991 psi | 87% | 3786 fps | 97% |
| Accurate LT-30 | <<locked>> | 84% | 46,282 psi | 90% | 3684 fps | 97.9% |
| Accurate LT-30 | <<locked>> | 84% | 45,556 psi | 88% | 3671 fps | 97.8% |
| Accurate LT-32 | <<locked>> | 84% | 45,890 psi | 89% | 3681 fps | 95.9% |
| ADI AR 2207 | <<locked>> | 82% | 46,485 psi | 90% | 3773 fps | 100% |
| ADI AR 2207 | <<locked>> | 82% | 45,527 psi | 88% | 3757 fps | 100% |
| ADI AR 2219 | <<locked>> | 84% | 45,063 psi | 88% | 3783 fps | 97.4% |
| ADI AR 2219 | <<locked>> | 84% | 44,164 psi | 86% | 3766 fps | 97.2% |
| Alliant AR-Comp | <<locked>> | 92% | 44,106 psi | 86% | 3812 fps | 100% |
| Alliant AR-Comp | <<locked>> | 94% | 46,398 psi | 90% | 3868 fps | 100% |
| Alliant Reloder-10x | <<locked>> | 86% | 44,831 psi | 87% | 3766 fps | 99.4% |
| Alliant Reloder-10x | <<locked>> | 86% | 43,816 psi | 85% | 3743 fps | 99.3% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 45,658 psi | 89% | 3648 fps | 98.2% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 44,889 psi | 87% | 3635 fps | 98.1% |
| Hodgdon H322 | <<locked>> | 86% | 43,845 psi | 85% | 3753 fps | 97.1% |
| Hodgdon H322 | <<locked>> | 88% | 46,064 psi | 89% | 3812 fps | 97.7% |
| Hodgdon H335 | <<locked>> | 86% | 45,034 psi | 87% | 3757 fps | 96.4% |
| Hodgdon H335 | <<locked>> | 86% | 44,121 psi | 86% | 3743 fps | 96.2% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 32,518 psi | 63% | 2579 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 32,242 psi | 63% | 2579 fps | 100% |
| IMR 3031 | <<locked>> | 94% | 45,179 psi | 88% | 3845 fps | 98.3% |
| IMR 3031 | <<locked>> | 94% | 44,150 psi | 86% | 3825 fps | 98.1% |
| IMR 4198 | <<locked>> | 86% | 45,614 psi | 89% | 3753 fps | 99.8% |
| IMR 4198 | <<locked>> | 86% | 44,875 psi | 87% | 3743 fps | 99.8% |
| Norma 200 | <<locked>> | 82% | 44,585 psi | 87% | 3737 fps | 99.7% |
| Norma 200 | <<locked>> | 84% | 46,427 psi | 90% | 3783 fps | 99.8% |
| Norma 202 | <<locked>> | 94% | 45,905 psi | 89% | 3776 fps | 96.7% |
| Norma 202 | <<locked>> | 94% | 44,918 psi | 87% | 3760 fps | 96.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 32,372 psi | 63% | 2635 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 32,010 psi | 62% | 2631 fps | 100% |
| Rottweil R 901 | <<locked>> | 92% | 45,397 psi | 88% | 3747 fps | 96.2% |
| SNPE Vectan SP 10 | <<locked>> | 84% | 45,788 psi | 89% | 3780 fps | 96.5% |
| SNPE Vectan SP 10 | <<locked>> | 84% | 44,817 psi | 87% | 3757 fps | 96.2% |
| SNPE Vectan SP 3 | <<locked>> | 86% | 45,484 psi | 88% | 3770 fps | 98.2% |
| SNPE Vectan SP 3 | <<locked>> | 86% | 44,672 psi | 87% | 3757 fps | 98.1% |
| SNPE Vectan Tubal 3000 | <<locked>> | 92% | 45,484 psi | 88% | 3675 fps | 96.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 92% | 44,512 psi | 86% | 3655 fps | 96.2% |
| SNPE Vectan Tubal 5000 | <<locked>> | 98% | 44,744 psi | 87% | 3655 fps | 97.5% |
| SNPE Vectan Tubal 5000 | <<locked>> | 98% | 43,888 psi | 85% | 3638 fps | 97.3% |
| Somchem S335 | <<locked>> | 92% | 44,730 psi | 87% | 3668 fps | 97.3% |
| Somchem S335 | <<locked>> | 94% | 46,354 psi | 90% | 3711 fps | 97.7% |
| Vihtavuori N120 | <<locked>> | 82% | 46,470 psi | 90% | 3717 fps | 100% |
| Vihtavuori N120 | <<locked>> | 82% | 45,585 psi | 89% | 3704 fps | 100% |
| Vihtavuori N130 | <<locked>> | 88% | 45,310 psi | 88% | 3694 fps | 99.3% |
| Vihtavuori N130 | <<locked>> | 88% | 44,411 psi | 86% | 3678 fps | 99.2% |
| Vihtavuori N133 | <<locked>> | 92% | 45,005 psi | 87% | 3684 fps | 98.7% |
| Vihtavuori N133 | <<locked>> | 92% | 44,121 psi | 86% | 3671 fps | 98.6% |
| Vihtavuori N135 | <<locked>> | 96% | 44,106 psi | 86% | 3750 fps | 98.9% |
| Vihtavuori N135 | <<locked>> | 98% | 45,948 psi | 89% | 3796 fps | 99.1% |
| Vihtavuori N140 | <<locked>> | 96% | 46,572 psi | 90% | 3757 fps | 97.3% |
| Vihtavuori N140 | <<locked>> | 96% | 45,643 psi | 89% | 3737 fps | 97.1% |
| Vihtavuori N540 | <<locked>> | 96% | 45,339 psi | 88% | 3730 fps | 96.5% |
| Vihtavuori N540 | <<locked>> | 96% | 44,396 psi | 86% | 3711 fps | 96.3% |
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>> | 82% | 34,243 psi | 67% | 3438 fps | 95.8% |
| Accurate 2015 | <<locked>> | 82% | 33,156 psi | 64% | 3412 fps | 95.4% |
| Accurate 2460 | <<locked>> | 86% | 43,120 psi | 84% | 3678 fps | 95.6% |
| Accurate 2460 | <<locked>> | 86% | 41,959 psi | 81% | 3655 fps | 95.3% |
| Accurate 2495 | <<locked>> | 88% | 32,735 psi | 64% | 3438 fps | 95.7% |
| Accurate 2495 | <<locked>> | 88% | 31,357 psi | 61% | 3399 fps | 95.1% |
| Accurate 2520 | <<locked>> | 90% | 42,670 psi | 83% | 3704 fps | 95% |
| Accurate 4064 | <<locked>> | 96% | 40,364 psi | 78% | 3665 fps | 95.6% |
| Accurate 4064 | <<locked>> | 96% | 39,001 psi | 76% | 3635 fps | 95.2% |
| Accurate LT-30 | <<locked>> | 80% | 40,872 psi | 79% | 3553 fps | 96.6% |
| Accurate LT-30 | <<locked>> | 80% | 40,132 psi | 78% | 3537 fps | 96.4% |
| Accurate LT-32 | <<locked>> | 82% | 43,250 psi | 84% | 3615 fps | 95.1% |
| ADI AR 2207 | <<locked>> | 80% | 43,381 psi | 84% | 3704 fps | 100% |
| ADI AR 2207 | <<locked>> | 80% | 42,409 psi | 82% | 3691 fps | 100% |
| ADI AR 2219 | <<locked>> | 80% | 39,030 psi | 76% | 3625 fps | 95.6% |
| ADI AR 2219 | <<locked>> | 80% | 38,159 psi | 74% | 3606 fps | 95.3% |
| Alliant AR-Comp | 39.3 gr | 80% | 29,370 psi | 57% | 3373 fps | 96.5% |
| Alliant AR-Comp | 39.3 gr | 80% | 28,500 psi | 55% | 3346 fps | 96.1% |
| Alliant Reloder-10x | <<locked>> | 80% | 36,724 psi | 71% | 3550 fps | 97.7% |
| Alliant Reloder-10x | <<locked>> | 80% | 35,737 psi | 69% | 3530 fps | 97.5% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 39,827 psi | 77% | 3507 fps | 96.7% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 39,088 psi | 76% | 3491 fps | 96.5% |
| Hodgdon H322 | <<locked>> | 82% | 38,232 psi | 74% | 3602 fps | 95.3% |
| Hodgdon H322 | <<locked>> | 82% | 37,362 psi | 73% | 3583 fps | 95% |
| Hodgdon H335 | <<locked>> | 84% | 41,872 psi | 81% | 3678 fps | 95.5% |
| Hodgdon H335 | <<locked>> | 84% | 40,959 psi | 80% | 3661 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 23,931 psi | 46% | 2326 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 23,612 psi | 46% | 2323 fps | 100% |
| IMR 3031 | 43.1 gr | 88% | 36,637 psi | 71% | 3615 fps | 95.7% |
| IMR 3031 | 43.1 gr | 88% | 35,694 psi | 69% | 3589 fps | 95.4% |
| IMR 4198 | <<locked>> | 80% | 37,913 psi | 74% | 3563 fps | 98.8% |
| IMR 4198 | <<locked>> | 80% | 37,188 psi | 72% | 3547 fps | 98.7% |
| Norma 200 | <<locked>> | 80% | 41,698 psi | 81% | 3665 fps | 99.3% |
| Norma 200 | <<locked>> | 80% | 40,480 psi | 79% | 3638 fps | 99.1% |
| Norma 202 | <<locked>> | 92% | 42,902 psi | 83% | 3707 fps | 95.9% |
| Norma 202 | <<locked>> | 92% | 41,974 psi | 82% | 3688 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 23,685 psi | 46% | 2372 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 23,308 psi | 45% | 2369 fps | 100% |
| Rottweil R 901 | <<locked>> | 90% | 42,757 psi | 83% | 3681 fps | 95.4% |
| SNPE Vectan SP 10 | <<locked>> | 82% | 42,554 psi | 83% | 3698 fps | 95.5% |
| SNPE Vectan SP 10 | <<locked>> | 82% | 41,669 psi | 81% | 3678 fps | 95.3% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 37,217 psi | 72% | 3556 fps | 95.9% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 36,361 psi | 71% | 3537 fps | 95.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 90% | 42,757 psi | 83% | 3612 fps | 95.7% |
| SNPE Vectan Tubal 3000 | <<locked>> | 90% | 41,843 psi | 81% | 3593 fps | 95.4% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 36,651 psi | 71% | 3451 fps | 95% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 38,406 psi | 75% | 3504 fps | 95.7% |
| Somchem S335 | <<locked>> | 88% | 39,276 psi | 76% | 3533 fps | 95.7% |
| Somchem S335 | <<locked>> | 88% | 38,290 psi | 74% | 3510 fps | 95.4% |
| Vihtavuori N120 | <<locked>> | 80% | 43,439 psi | 84% | 3655 fps | 100% |
| Vihtavuori N120 | <<locked>> | 80% | 42,540 psi | 83% | 3638 fps | 100% |
| Vihtavuori N130 | <<locked>> | 80% | 35,157 psi | 68% | 3432 fps | 97.1% |
| Vihtavuori N130 | <<locked>> | 80% | 34,243 psi | 67% | 3412 fps | 96.8% |
| Vihtavuori N133 | <<locked>> | 82% | 32,518 psi | 63% | 3350 fps | 95% |
| Vihtavuori N133 | <<locked>> | 84% | 33,953 psi | 66% | 3402 fps | 95.7% |
| Vihtavuori N135 | 42.2 gr | 88% | 33,431 psi | 65% | 3465 fps | 95.8% |
| Vihtavuori N135 | 42.2 gr | 88% | 32,474 psi | 63% | 3438 fps | 95.4% |
| Vihtavuori N140 | <<locked>> | 92% | 40,712 psi | 79% | 3615 fps | 95.7% |
| Vihtavuori N140 | <<locked>> | 92% | 39,827 psi | 77% | 3593 fps | 95.4% |
| Vihtavuori N540 | <<locked>> | 94% | 42,177 psi | 82% | 3652 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 94% | 41,249 psi | 80% | 3635 fps | 95.3% |
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 136 powders for .257 Roberts loaded with the .257 | 52gr | Peregrine VRG-3. Alliant AR-Comp delivers the highest muzzle velocity at 3,868 fps; across all powders the maximum-charge window runs from 2,579 fps to 3,868 fps. Accurate 4064 gives the best case fill at 100 %, and 136 of the 136 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (355 MPa), the top charges use 62–90 %, leaving at least 10 % headroom. Accurate 4064, Accurate 4064, Alliant Reloder- TS 15.5 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. IMR 3031, Alliant AR-Comp, Vihtavuori N135 rank at the top here: for .257 Roberts with the .257 | 52gr | Peregrine VRG-3 they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2206H, ADI AR 2206H, ADI Benchmark 8208 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.