Load Specifications
Load data in caliber .270 Win. Ackley Improved with .277 | 90gr | CutEdge ER Raptor bullet and 96 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Power Pro 2000-MR, ReloadSwiss RS 52 and Hodgdon CFE223.
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: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 1680 | <<locked>> | 82% | 62,178 psi | 86% | 3409 fps | 100% |
| Accurate 2015 | <<locked>> | 94% | 63,672 psi | 88% | 3507 fps | 100% |
| Accurate 2200 | <<locked>> | 86% | 64,136 psi | 88% | 3635 fps | 98.8% |
| Accurate 2230 | <<locked>> | 84% | 61,641 psi | 85% | 3579 fps | 98.8% |
| Accurate 2460 | <<locked>> | 90% | 62,642 psi | 86% | 3533 fps | 100% |
| Accurate 2495ᴾ | <<locked>> | 100% | 65,586 psi | 90% | 3566 fps | 100% |
| Accurate 2520 | <<locked>> | 94% | 65,209 psi | 90% | 3606 fps | 100% |
| Accurate 4064ᴾ | <<locked>> | 100% | 60,684 psi | 84% | 3550 fps | 100% |
| Accurate LT-30 | <<locked>> | 88% | 63,034 psi | 87% | 3451 fps | 100% |
| Accurate LT-32 | <<locked>> | 88% | 63,527 psi | 88% | 3481 fps | 100% |
| ADI APS 450 | <<locked>> | 88% | 64,963 psi | 90% | 2799 fps | 100% |
| ADI AR 2206H | <<locked>> | 96% | 62,961 psi | 87% | 3606 fps | 99.3% |
| ADI AR 2207 | <<locked>> | 86% | 64,643 psi | 89% | 3481 fps | 100% |
| ADI AR 2208ᴾ | <<locked>> | 100% | 60,104 psi | 83% | 3527 fps | 98.5% |
| ADI AR 2219 | <<locked>> | 88% | 65,137 psi | 90% | 3599 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 94% | 61,989 psi | 85% | 3553 fps | 99.8% |
| Alliant AR-Comp | <<locked>> | 94% | 61,844 psi | 85% | 3537 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 90% | 63,918 psi | 88% | 3694 fps | 99.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 98% | 63,860 psi | 88% | 3740 fps | 99% |
| Alliant Reloder- TS 15.5ᴾ | <<locked>> | 100% | 59,495 psi | 82% | 3550 fps | 99.5% |
| Alliant Reloder-10x | <<locked>> | 90% | 62,874 psi | 87% | 3520 fps | 100% |
| Alliant Reloder-15ᴾ | <<locked>> | 100% | 64,440 psi | 89% | 3642 fps | 99.2% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 53,301 psi | 74% | 3540 fps | 98.7% |
| Alliant Reloder-7 | <<locked>> | 84% | 61,815 psi | 85% | 3445 fps | 100% |
| Baschieri & Pellagri 106 | <<locked>> | 88% | 62,961 psi | 87% | 3435 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 96% | 63,643 psi | 88% | 3615 fps | 98.7% |
| Bofors RP3ᴾ | <<locked>> | 100% | 60,495 psi | 83% | 3573 fps | 99.6% |
| Hodgdon Benchmark | <<locked>> | 94% | 64,266 psi | 89% | 3540 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 94% | 61,728 psi | 85% | 3586 fps | 99.9% |
| Hodgdon CFE223 | <<locked>> | 92% | 64,295 psi | 89% | 3707 fps | 99.2% |
| Hodgdon H322 | <<locked>> | 90% | 62,961 psi | 87% | 3570 fps | 100% |
| Hodgdon H335 | <<locked>> | 90% | 65,137 psi | 90% | 3599 fps | 100% |
| Hodgdon H380ᴾ | <<locked>> | 100% | 62,250 psi | 86% | 3583 fps | 97.9% |
| Hodgdon H4198 | <<locked>> | 86% | 65,311 psi | 90% | 3517 fps | 100% |
| Hodgdon H4895 | <<locked>> | 96% | 63,527 psi | 88% | 3619 fps | 99.6% |
| Hodgdon LEVERevolution | <<locked>> | 98% | 63,048 psi | 87% | 3648 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,098 psi | 47% | 2172 fps | 100% |
| Hodgdon VARGET | <<locked>> | 96% | 61,366 psi | 85% | 3560 fps | 99.4% |
| IMR 3031 | <<locked>> | 96% | 62,656 psi | 86% | 3609 fps | 100% |
| IMR 4064ᴾ | <<locked>> | 100% | 63,382 psi | 87% | 3573 fps | 99.1% |
| IMR 4166 Enduron | <<locked>> | 98% | 64,614 psi | 89% | 3550 fps | 96.1% |
| IMR 4198 | <<locked>> | 90% | 63,121 psi | 87% | 3481 fps | 100% |
| IMR 4227 | <<locked>> | 82% | 64,252 psi | 89% | 3432 fps | 100% |
| IMR 4895 | <<locked>> | 98% | 62,120 psi | 86% | 3622 fps | 99.3% |
| IMR 8208 XBR | <<locked>> | 94% | 61,989 psi | 85% | 3553 fps | 99.8% |
| Lovex D073.4 | <<locked>> | 84% | 62,395 psi | 86% | 3556 fps | 100% |
| Lovex D073.5 | <<locked>> | 90% | 62,932 psi | 87% | 3543 fps | 100% |
| Lovex D073.6 | <<locked>> | 96% | 62,642 psi | 86% | 3576 fps | 100% |
| Lovex S053 | <<locked>> | 82% | 62,424 psi | 86% | 3356 fps | 100% |
| Lovex S060 | <<locked>> | 96% | 62,888 psi | 87% | 3524 fps | 99.3% |
| Lovex S062ᴾ | <<locked>> | 100% | 62,424 psi | 86% | 3566 fps | 99.8% |
| Norma 200 | <<locked>> | 86% | 62,845 psi | 87% | 3491 fps | 100% |
| Norma 201 | <<locked>> | 98% | 65,137 psi | 90% | 3596 fps | 99.9% |
| Norma 202 | <<locked>> | 96% | 61,902 psi | 85% | 3550 fps | 100% |
| Norma 203Bᴾ | <<locked>> | 100% | 63,411 psi | 87% | 3625 fps | 99.4% |
| Ramshot Big Gameᴾ | <<locked>> | 100% | 65,267 psi | 90% | 3658 fps | 99.4% |
| Ramshot TAC | <<locked>> | 94% | 63,585 psi | 88% | 3566 fps | 97.5% |
| Ramshot Wild Boar | <<locked>> | 94% | 62,714 psi | 86% | 3593 fps | 99.3% |
| Ramshot X-Terminator | <<locked>> | 92% | 64,281 psi | 89% | 3560 fps | 99.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,345 psi | 47% | 2224 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 82% | 65,354 psi | 90% | 3474 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 90% | 61,815 psi | 85% | 3547 fps | 100% |
| ReloadSwiss RS 50ᴾ | <<locked>> | 100% | 63,150 psi | 87% | 3560 fps | 96.6% |
| ReloadSwiss RS 52 | <<locked>> | 98% | 65,514 psi | 90% | 3730 fps | 99.2% |
| ReloadSwiss RS 60ᴾ | <<locked>> | 100% | 57,014 psi | 79% | 3629 fps | 100% |
| Rottweil R 901 | <<locked>> | 96% | 65,383 psi | 90% | 3583 fps | 100% |
| Rottweil R 902ᴾ | <<locked>> | 100% | 65,369 psi | 90% | 3589 fps | 99.9% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 55,825 psi | 77% | 3484 fps | 99% |
| Shooters World AR Plus | <<locked>> | 84% | 62,395 psi | 86% | 3556 fps | 100% |
| Shooters World Match Rifle | <<locked>> | 96% | 62,642 psi | 86% | 3576 fps | 100% |
| Shooters World Precisionᴾ | <<locked>> | 100% | 62,424 psi | 86% | 3566 fps | 99.8% |
| Shooters World Tactical Rifle | <<locked>> | 88% | 62,511 psi | 86% | 3514 fps | 99.6% |
| SNPE Vectan BA6 1/2 | <<locked>> | 88% | 64,890 psi | 89% | 3199 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 88% | 65,412 psi | 90% | 3606 fps | 100% |
| SNPE Vectan SP 11ᴾ | <<locked>> | 100% | 58,305 psi | 80% | 3560 fps | 98.8% |
| SNPE Vectan SP 3 | <<locked>> | 90% | 64,600 psi | 89% | 3553 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 94% | 61,525 psi | 85% | 3533 fps | 97.7% |
| SNPE Vectan SP 9 | <<locked>> | 96% | 61,482 psi | 85% | 3563 fps | 99.2% |
| SNPE Vectan Tubal 3000 | <<locked>> | 96% | 63,802 psi | 88% | 3491 fps | 100% |
| SNPE Vectan Tubal 5000ᴾ | <<locked>> | 100% | 59,799 psi | 82% | 3415 fps | 100% |
| Somchem S321 | <<locked>> | 92% | 64,353 psi | 89% | 3599 fps | 99.9% |
| Somchem S335 | <<locked>> | 96% | 62,424 psi | 86% | 3474 fps | 100% |
| Somchem S341 | <<locked>> | 96% | 65,224 psi | 90% | 3593 fps | 99.4% |
| Somchem S355ᴾ | <<locked>> | 100% | 56,536 psi | 78% | 3488 fps | 98.9% |
| Somchem S365ᴾ | <<locked>> | 100% | 40,596 psi | 56% | 3258 fps | 97.1% |
| Vihtavuori N120 | <<locked>> | 86% | 64,353 psi | 89% | 3412 fps | 100% |
| Vihtavuori N130 | <<locked>> | 92% | 63,135 psi | 87% | 3455 fps | 100% |
| Vihtavuori N133 | <<locked>> | 96% | 63,527 psi | 88% | 3468 fps | 100% |
| Vihtavuori N135ᴾ | <<locked>> | 100% | 64,701 psi | 89% | 3556 fps | 100% |
| Vihtavuori N140 | <<locked>> | 98% | 62,468 psi | 86% | 3517 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 54,708 psi | 75% | 3409 fps | 99.5% |
| Vihtavuori N530 | <<locked>> | 94% | 63,164 psi | 87% | 3560 fps | 99.8% |
| Vihtavuori N540ᴾ | <<locked>> | 100% | 65,122 psi | 90% | 3573 fps | 100% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 50,154 psi | 69% | 3330 fps | 98.2% |
| Winchester 748 | <<locked>> | 94% | 62,801 psi | 87% | 3612 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 96% | 61,482 psi | 85% | 3573 fps | 99.5% |
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% | 58,189 psi | 80% | 3353 fps | 100% |
| Accurate 2015 | <<locked>> | 80% | 40,509 psi | 56% | 3107 fps | 99.9% |
| Accurate 2200 | <<locked>> | 80% | 52,402 psi | 72% | 3425 fps | 97% |
| Accurate 2230 | <<locked>> | 80% | 53,243 psi | 73% | 3432 fps | 97.6% |
| Accurate 2460 | <<locked>> | 80% | 44,135 psi | 61% | 3212 fps | 99.1% |
| Accurate 2495 | <<locked>> | 80% | 32,590 psi | 45% | 2956 fps | 99% |
| Accurate 2520 | <<locked>> | 80% | 39,407 psi | 54% | 3133 fps | 97.8% |
| Accurate 4064 | <<locked>> | 80% | 30,850 psi | 43% | 2920 fps | 96.1% |
| Accurate LT-30 | <<locked>> | 80% | 49,327 psi | 68% | 3232 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 49,705 psi | 69% | 3251 fps | 99.5% |
| ADI APS 450 | <<locked>> | 80% | 56,898 psi | 78% | 2674 fps | 100% |
| ADI AR 2206H | <<locked>> | 84% | 42,540 psi | 59% | 3209 fps | 95.5% |
| ADI AR 2207 | <<locked>> | 80% | 53,505 psi | 74% | 3317 fps | 100% |
| ADI AR 2208 | <<locked>> | 90% | 43,903 psi | 61% | 3215 fps | 95.1% |
| ADI AR 2219 | <<locked>> | 80% | 49,342 psi | 68% | 3346 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 39,349 psi | 54% | 3107 fps | 96% |
| Alliant AR-Comp | <<locked>> | 80% | 38,159 psi | 53% | 3133 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 45,469 psi | 63% | 3346 fps | 97% |
| Alliant Power Pro 2000-MR | 55.8 gr | 90% | 47,906 psi | 66% | 3428 fps | 95.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 37,565 psi | 52% | 3100 fps | 95% |
| Alliant Reloder-10x | <<locked>> | 80% | 45,818 psi | 63% | 3238 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 88% | 43,352 psi | 60% | 3245 fps | 95.2% |
| Alliant Reloder-17 | <<locked>> | 92% | 40,263 psi | 56% | 3241 fps | 95.1% |
| Alliant Reloder-7 | <<locked>> | 80% | 54,694 psi | 75% | 3340 fps | 100% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 48,399 psi | 67% | 3209 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 45,005 psi | 62% | 3271 fps | 95% |
| Bofors RP3 | <<locked>> | 88% | 39,566 psi | 55% | 3163 fps | 95.9% |
| Hodgdon Benchmark | <<locked>> | 80% | 41,466 psi | 57% | 3120 fps | 97.3% |
| Hodgdon BL-C2 | <<locked>> | 80% | 37,434 psi | 52% | 3104 fps | 96.1% |
| Hodgdon CFE223 | 52.1 gr | 82% | 44,628 psi | 62% | 3337 fps | 95.5% |
| Hodgdon H322 | <<locked>> | 80% | 44,889 psi | 62% | 3258 fps | 99.7% |
| Hodgdon H335 | <<locked>> | 80% | 45,977 psi | 63% | 3274 fps | 99.5% |
| Hodgdon H380 | <<locked>> | 94% | 50,502 psi | 70% | 3373 fps | 95.7% |
| Hodgdon H4198 | <<locked>> | 80% | 54,302 psi | 75% | 3346 fps | 100% |
| Hodgdon H4895 | <<locked>> | 82% | 39,987 psi | 55% | 3156 fps | 95.4% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 38,682 psi | 53% | 3166 fps | 95.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,208 psi | 35% | 1949 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 41,292 psi | 57% | 3166 fps | 95.7% |
| IMR 3031 | <<locked>> | 80% | 36,230 psi | 50% | 3110 fps | 99% |
| IMR 4064 | <<locked>> | 88% | 43,047 psi | 59% | 3192 fps | 95.2% |
| IMR 4166 Enduron | <<locked>> | 96% | 60,452 psi | 83% | 3484 fps | 95.3% |
| IMR 4198 | <<locked>> | 80% | 46,760 psi | 64% | 3219 fps | 100% |
| IMR 4227 | <<locked>> | 80% | 60,321 psi | 83% | 3379 fps | 100% |
| IMR 4895 | <<locked>> | 86% | 41,655 psi | 57% | 3222 fps | 95.4% |
| IMR 8208 XBR | <<locked>> | 80% | 39,349 psi | 54% | 3107 fps | 96% |
| Lovex D073.4 | <<locked>> | 80% | 53,911 psi | 74% | 3419 fps | 99.8% |
| Lovex D073.5 | <<locked>> | 80% | 44,092 psi | 61% | 3209 fps | 98.2% |
| Lovex D073.6 | <<locked>> | 80% | 35,476 psi | 49% | 3045 fps | 96.6% |
| Lovex S053 | <<locked>> | 80% | 59,030 psi | 81% | 3307 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 40,480 psi | 56% | 3087 fps | 95% |
| Lovex S062 | <<locked>> | 84% | 37,362 psi | 52% | 3068 fps | 95.5% |
| Norma 200 | <<locked>> | 80% | 51,880 psi | 72% | 3323 fps | 100% |
| Norma 201 | <<locked>> | 80% | 36,390 psi | 50% | 3028 fps | 95.1% |
| Norma 202 | <<locked>> | 80% | 36,419 psi | 50% | 3051 fps | 97.6% |
| Norma 203B | <<locked>> | 88% | 42,569 psi | 59% | 3228 fps | 95.6% |
| Ramshot Big Game | <<locked>> | 88% | 42,772 psi | 59% | 3245 fps | 95.4% |
| Ramshot TAC | <<locked>> | 88% | 51,750 psi | 71% | 3360 fps | 95.2% |
| Ramshot Wild Boar | <<locked>> | 82% | 41,249 psi | 57% | 3179 fps | 95.1% |
| Ramshot X-Terminator | <<locked>> | 80% | 42,830 psi | 59% | 3159 fps | 95.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,309 psi | 35% | 1995 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 80% | 61,525 psi | 85% | 3422 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 44,338 psi | 61% | 3225 fps | 98.6% |
| ReloadSwiss RS 50 | <<locked>> | 98% | 59,030 psi | 81% | 3491 fps | 95.8% |
| ReloadSwiss RS 52 | 52.9 gr | 88% | 45,585 psi | 63% | 3369 fps | 95.7% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 34,896 psi | 48% | 3104 fps | 95.5% |
| Rottweil R 901 | <<locked>> | 80% | 39,900 psi | 55% | 3110 fps | 98.2% |
| Rottweil R 902 | <<locked>> | 82% | 36,738 psi | 51% | 3028 fps | 95.2% |
| Rottweil R 903 | <<locked>> | 90% | 39,450 psi | 54% | 3150 fps | 95.5% |
| Shooters World AR Plus | <<locked>> | 80% | 53,911 psi | 74% | 3419 fps | 99.8% |
| Shooters World Match Rifle | <<locked>> | 80% | 35,476 psi | 49% | 3045 fps | 96.6% |
| Shooters World Precision | <<locked>> | 84% | 37,362 psi | 52% | 3068 fps | 95.5% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 46,992 psi | 65% | 3241 fps | 97.7% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 52,707 psi | 73% | 3035 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 49,893 psi | 69% | 3353 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 90% | 41,423 psi | 57% | 3219 fps | 95% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 46,601 psi | 64% | 3261 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 49,705 psi | 69% | 3323 fps | 95.3% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 41,191 psi | 57% | 3166 fps | 95.1% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 37,985 psi | 52% | 3012 fps | 98% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 31,038 psi | 43% | 2835 fps | 97% |
| Somchem S321 | <<locked>> | 80% | 42,322 psi | 58% | 3196 fps | 97.2% |
| Somchem S335 | <<locked>> | 80% | 37,652 psi | 52% | 3015 fps | 98.7% |
| Somchem S341 | <<locked>> | 84% | 42,685 psi | 59% | 3186 fps | 95.5% |
| Somchem S355 | <<locked>> | 90% | 40,727 psi | 56% | 3169 fps | 95.6% |
| Somchem S365 | <<locked>> | 96% | 35,520 psi | 49% | 3117 fps | 95.1% |
| Vihtavuori N120 | <<locked>> | 80% | 53,417 psi | 74% | 3261 fps | 100% |
| Vihtavuori N130 | <<locked>> | 80% | 43,207 psi | 60% | 3127 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 38,130 psi | 53% | 3025 fps | 99.7% |
| Vihtavuori N135 | <<locked>> | 80% | 33,199 psi | 46% | 2972 fps | 99% |
| Vihtavuori N140 | <<locked>> | 80% | 34,519 psi | 48% | 2976 fps | 97.4% |
| Vihtavuori N150 | <<locked>> | 88% | 36,434 psi | 50% | 3031 fps | 95.8% |
| Vihtavuori N530 | <<locked>> | 80% | 39,233 psi | 54% | 3097 fps | 96.1% |
| Vihtavuori N540 | <<locked>> | 80% | 33,243 psi | 46% | 2949 fps | 96.5% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 40,611 psi | 56% | 3123 fps | 95.6% |
| Winchester 748 | <<locked>> | 80% | 38,319 psi | 53% | 3140 fps | 96.7% |
| Winchester StaBALL Match | <<locked>> | 84% | 40,524 psi | 56% | 3166 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 96 powders for .270 Win. Ackley Improved loaded with the .277 | 90gr | CutEdge ER Raptor. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,740 fps; across all powders the maximum-charge window runs from 2,172 fps to 3,740 fps. Accurate 2495 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 (500 MPa), the top charges use 47–90 %, leaving at least 10 % headroom. The 90.0 gr projectile in 0.277" calls for a 1:9.0 twist; slower twists will usually not stabilise this weight. 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. Alliant Power Pro 2000-MR, ReloadSwiss RS 52, Hodgdon CFE223 rank at the top here: for .270 Win. Ackley Improved with the .277 | 90gr | CutEdge ER Raptor 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.