Load data for .378 Weath. Mag. + .375 | 270gr | Barnes XLC S

.378 Weath. Mag. cartridge drawing
Barnes logo

Load Specifications

Bullet Manufacturer:Barnes
Bullet Weight:270 gr
Bullet Diameter:0.375"
Bullet Length:<<locked>>
Case Length (l3):2.913"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:137 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:26"
Max. allowed Pressure:63,817 psi
Recommended Twist Rate:1:6.0

Load data in caliber .378 Weath. Mag. with .375 | 270gr | Barnes XLC S bullet and 82 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Accurate MAGPRO and Accurate High Country.

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: 26"

PowderChargeFRMaxP%V(0)z
Accurate 3100<<locked>>96%54,273 psi85%2854 fps99.9%
Accurate 4350<<locked>>88%55,999 psi88%2890 fps100%
Accurate High Country<<locked>>94%54,679 psi86%2992 fps98.3%
Accurate MAGPRO<<locked>>96%55,448 psi87%2989 fps97.3%
ADI AR 2208<<locked>>84%57,130 psi90%2844 fps100%
ADI AR 2209<<locked>>94%55,767 psi87%2930 fps99%
ADI AR 2213<<locked>>98%57,072 psi89%2986 fps98.3%
ADI AR 2217ᴾ<<locked>>100%45,179 psi71%2762 fps95.9%
ADI AR 2225ᴾ<<locked>>100%40,466 psi63%2733 fps97.9%
Alliant Power Pro Varmint<<locked>>94%55,999 psi88%2927 fps99%
Alliant Reloder- TS 15.5<<locked>>82%55,187 psi86%2822 fps100%
Alliant Reloder-16<<locked>>90%55,680 psi87%2936 fps100%
Alliant Reloder-17<<locked>>86%57,058 psi89%2956 fps100%
Alliant Reloder-19<<locked>>94%55,288 psi87%2920 fps99%
Alliant Reloder-22<<locked>>98%56,768 psi89%2989 fps99.3%
Alliant Reloder-23ᴾ<<locked>>100%57,421 psi90%2959 fps100%
Alliant Reloder-25ᴾ<<locked>>100%50,038 psi78%2910 fps100%
Alliant Reloder-26<<locked>>94%54,041 psi85%3002 fps100%
Bofors RP15ᴾ<<locked>>100%55,637 psi87%2969 fps99.1%
Bofors RP3<<locked>>82%56,579 psi89%2844 fps100%
Bofors RP30ᴾ<<locked>>100%46,253 psi72%2841 fps97%
Bofors RP5<<locked>>98%56,768 psi89%2989 fps99.3%
Bofors RP7<<locked>>86%55,245 psi87%2831 fps99.4%
Hodgdon H1000ᴾ<<locked>>100%49,371 psi77%2848 fps97.7%
Hodgdon H380<<locked>>82%56,289 psi88%2861 fps100%
Hodgdon H414<<locked>>88%57,145 psi90%2936 fps99.8%
Hodgdon H4350<<locked>>86%56,492 psi89%2890 fps99.2%
Hodgdon H4831<<locked>>96%57,087 psi89%2923 fps97.7%
Hodgdon H4831 SC<<locked>>96%56,115 psi88%2910 fps97.6%
Hodgdon Hybrid 100V<<locked>>92%56,405 psi88%2858 fps100%
Hodgdon Retumboᴾ<<locked>>100%49,124 psi77%2963 fps99%
Hodgdon Superformance<<locked>>88%57,174 psi90%2972 fps99.8%
Hodgdon TrailBossᴾ<<locked>>100%37,115 psi58%1778 fps100%
IMR 4064<<locked>>82%56,797 psi89%2828 fps100%
IMR 4350<<locked>>90%56,130 psi88%2867 fps99.6%
IMR 4451 Enduron<<locked>>86%56,289 psi88%2851 fps99.7%
IMR 4831<<locked>>90%56,130 psi88%2881 fps100%
IMR 4955 Enduron<<locked>>94%55,114 psi86%2858 fps97.6%
IMR 7828 SSC<<locked>>98%54,824 psi86%2963 fps98.1%
Lovex S062<<locked>>82%57,609 psi90%2825 fps100%
Lovex S065<<locked>>88%57,087 psi89%2854 fps100%
Lovex S070<<locked>>88%55,361 psi87%2851 fps99.8%
Lovex S071ᴾ<<locked>>100%51,982 psi81%2818 fps99.8%
Norma 204<<locked>>90%56,826 psi89%2920 fps99%
Norma 217ᴾ<<locked>>100%36,303 psi57%2664 fps95.9%
Norma MRP<<locked>>96%56,507 psi89%3015 fps99.9%
Norma URP<<locked>>90%57,464 psi90%2920 fps100%
Ramshot Grand<<locked>>98%55,201 psi87%2979 fps98.5%
Ramshot Hunter<<locked>>90%56,159 psi88%2927 fps100%
Ramshot Magnumᴾ<<locked>>100%53,374 psi84%2917 fps99.4%
ReloadSwiss RS 14ᴾ<<locked>>100%37,913 psi59%1821 fps100%
ReloadSwiss RS 50<<locked>>82%55,869 psi88%2844 fps99.9%
ReloadSwiss RS 60<<locked>>84%56,463 psi88%2943 fps100%
ReloadSwiss RS 62<<locked>>88%55,463 psi87%2910 fps100%
ReloadSwiss RS 70<<locked>>90%56,956 psi89%2989 fps100%
ReloadSwiss RS 76ᴾ<<locked>>100%49,356 psi77%2959 fps99.7%
Rottweil R 903<<locked>>84%56,724 psi89%2844 fps100%
Rottweil R 904<<locked>>94%57,363 psi90%2897 fps98.4%
Rottweil R 905<<locked>>94%54,998 psi86%2910 fps99.1%
Rottweil R 907<<locked>>86%55,245 psi87%2831 fps99.4%
Shooters World Long Rifle<<locked>>88%57,087 psi89%2854 fps100%
Shooters World Precision<<locked>>82%57,609 psi90%2825 fps100%
Shooters World SW4350<<locked>>88%55,361 psi87%2851 fps99.8%
SNPE Vectan SP 11<<locked>>84%57,377 psi90%2894 fps100%
SNPE Vectan Tubal 5000<<locked>>84%56,391 psi88%2710 fps100%
SNPE Vectan Tubal 7000<<locked>>88%56,594 psi89%2808 fps99.8%
SNPE Vectan Tubal 8000<<locked>>94%54,534 psi85%2907 fps99%
Somchem S355<<locked>>84%56,304 psi88%2835 fps100%
Somchem S361<<locked>>92%55,579 psi87%2838 fps97.4%
Somchem S365<<locked>>92%57,363 psi90%2920 fps100%
Somchem S385<<locked>>94%55,825 psi87%2887 fps99.5%
Vihtavuori N150<<locked>>86%57,217 psi90%2802 fps100%
Vihtavuori N160<<locked>>88%55,898 psi88%2861 fps100%
Vihtavuori N165<<locked>>98%54,839 psi86%2861 fps99.2%
Vihtavuori N550<<locked>>88%55,201 psi87%2867 fps100%
Vihtavuori N555<<locked>>96%57,058 psi89%2943 fps100%
Vihtavuori N560<<locked>>96%56,492 psi89%3005 fps98%
Vihtavuori N565ᴾ<<locked>>100%52,518 psi82%2923 fps97.5%
Winchester 6.5 StaBALL<<locked>>88%55,013 psi86%2822 fps100%
Winchester 760<<locked>>88%57,290 psi90%2940 fps99.9%
Winchester StaBALL HDᴾ<<locked>>100%53,519 psi84%3041 fps100%
Winchester Supreme 780<<locked>>96%55,288 psi87%2877 fps98.9%

Recommended = one of the top powders for this cartridge and bullet combination.

Start Load - Barrel Length: 26"

PowderChargeFRMaxP%V(0)z
Accurate 3100<<locked>>80%33,040 psi52%2444 fps96.3%
Accurate 4350<<locked>>80%43,497 psi68%2684 fps99.8%
Accurate High Country97.7 gr86%42,119 psi66%2756 fps95.4%
Accurate MAGPRO106.5 gr92%48,617 psi76%2871 fps95.7%
ADI AR 2208<<locked>>80%50,705 psi79%2746 fps100%
ADI AR 2209<<locked>>82%38,522 psi60%2602 fps95.1%
ADI AR 2213<<locked>>90%44,353 psi70%2756 fps95.5%
ADI AR 2217<<locked>>98%42,424 psi66%2703 fps95%
ADI AR 2225<<locked>>94%33,953 psi53%2562 fps95.2%
Alliant Power Pro Varmint<<locked>>82%38,798 psi61%2605 fps95.3%
Alliant Reloder- TS 15.5<<locked>>80%52,040 psi82%2776 fps100%
Alliant Reloder-16<<locked>>80%41,060 psi64%2680 fps99.8%
Alliant Reloder-17<<locked>>80%46,775 psi73%2799 fps100%
Alliant Reloder-19<<locked>>82%38,464 psi60%2598 fps95.3%
Alliant Reloder-22<<locked>>86%38,972 psi61%2657 fps95.7%
Alliant Reloder-23<<locked>>80%31,285 psi49%2467 fps99%
Alliant Reloder-25<<locked>>82%29,414 psi46%2425 fps95.1%
Alliant Reloder-2693.6 gr80%33,605 psi53%2592 fps98%
Bofors RP15<<locked>>88%38,653 psi61%2648 fps95.4%
Bofors RP3<<locked>>80%53,156 psi83%2795 fps100%
Bofors RP30<<locked>>96%40,814 psi64%2730 fps95.4%
Bofors RP5<<locked>>86%38,972 psi61%2657 fps95.7%
Bofors RP7<<locked>>80%46,253 psi72%2677 fps98.3%
Hodgdon H1000<<locked>>94%40,886 psi64%2674 fps95.2%
Hodgdon H380<<locked>>80%52,939 psi83%2808 fps100%
Hodgdon H414<<locked>>80%44,570 psi70%2720 fps98.5%
Hodgdon H4350<<locked>>80%47,065 psi74%2730 fps97.9%
Hodgdon H4831<<locked>>90%47,253 psi74%2759 fps95.7%
Hodgdon H4831 SC<<locked>>90%46,398 psi73%2743 fps95.4%
Hodgdon Hybrid 100V<<locked>>80%39,059 psi61%2575 fps99.9%
Hodgdon Retumbo<<locked>>92%38,508 psi60%2720 fps95.9%
Hodgdon Superformance<<locked>>80%43,424 psi68%2740 fps98%
Hodgdon TrailBoss<<locked>>80%27,934 psi44%1591 fps100%
IMR 4064<<locked>>80%53,374 psi84%2779 fps100%
IMR 4350<<locked>>80%41,582 psi65%2608 fps97.3%
IMR 4451 Enduron<<locked>>80%47,224 psi74%2700 fps98.8%
IMR 4831<<locked>>80%41,263 psi65%2628 fps99.6%
IMR 4955 Enduron<<locked>>88%46,093 psi72%2700 fps95.6%
IMR 7828 SSC<<locked>>90%42,583 psi67%2733 fps95.1%
Lovex S062<<locked>>80%54,201 psi85%2776 fps100%
Lovex S065<<locked>>80%45,339 psi71%2657 fps99.3%
Lovex S070<<locked>>80%43,758 psi69%2648 fps98.4%
Lovex S071<<locked>>82%30,618 psi48%2382 fps95.3%
Norma 204<<locked>>80%41,234 psi65%2641 fps95.9%
Norma 217<<locked>>98%34,272 psi54%2612 fps95%
Norma MRP<<locked>>80%33,663 psi53%2556 fps95.2%
Norma URP<<locked>>80%42,424 psi66%2667 fps99.6%
Ramshot Grand<<locked>>90%42,366 psi66%2740 fps95.4%
Ramshot Hunter<<locked>>80%41,031 psi64%2657 fps98.5%
Ramshot Magnum<<locked>>88%35,679 psi56%2569 fps95.1%
ReloadSwiss RS 14<<locked>>80%28,500 psi45%1627 fps100%
ReloadSwiss RS 50<<locked>>80%52,475 psi82%2789 fps99.7%
ReloadSwiss RS 60<<locked>>80%49,429 psi77%2841 fps100%
ReloadSwiss RS 62<<locked>>80%42,844 psi67%2697 fps99.6%
ReloadSwiss RS 70<<locked>>80%40,959 psi64%2707 fps99.3%
ReloadSwiss RS 76<<locked>>90%35,592 psi56%2641 fps95.9%
Rottweil R 903<<locked>>80%50,285 psi79%2746 fps100%
Rottweil R 904<<locked>>84%42,453 psi67%2635 fps95.2%
Rottweil R 905<<locked>>82%37,797 psi59%2585 fps95.3%
Rottweil R 907<<locked>>80%46,253 psi72%2677 fps98.3%
Shooters World Long Rifle<<locked>>80%45,339 psi71%2657 fps99.3%
Shooters World Precision<<locked>>80%54,201 psi85%2776 fps100%
Shooters World SW4350<<locked>>80%43,758 psi69%2648 fps98.4%
SNPE Vectan SP 11<<locked>>80%50,633 psi79%2792 fps100%
SNPE Vectan Tubal 5000<<locked>>80%50,227 psi79%2625 fps100%
SNPE Vectan Tubal 7000<<locked>>80%44,411 psi70%2605 fps98.4%
SNPE Vectan Tubal 8000<<locked>>82%37,449 psi59%2582 fps95.1%
Somchem S355<<locked>>80%50,024 psi78%2740 fps100%
Somchem S361<<locked>>86%46,006 psi72%2674 fps95.3%
Somchem S365<<locked>>80%39,088 psi61%2631 fps100%
Somchem S385<<locked>>80%36,419 psi57%2523 fps95.7%
Vihtavuori N150<<locked>>80%47,819 psi75%2664 fps100%
Vihtavuori N160<<locked>>80%43,700 psi68%2657 fps99.7%
Vihtavuori N165<<locked>>84%35,636 psi56%2500 fps95%
Vihtavuori N550<<locked>>80%43,250 psi68%2667 fps99.6%
Vihtavuori N555<<locked>>80%35,041 psi55%2546 fps99%
Vihtavuori N560<<locked>>88%43,685 psi68%2769 fps95%
Vihtavuori N565<<locked>>94%43,439 psi68%2756 fps95.3%
Winchester 6.5 StaBALL<<locked>>80%42,438 psi67%2621 fps100%
Winchester 760<<locked>>80%44,686 psi70%2723 fps98.5%
Winchester StaBALL HD<<locked>>80%28,079 psi44%2477 fps99%
Winchester Supreme 780<<locked>>86%40,001 psi63%2605 fps95.8%

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.

<<locked>> you need an access license to unlock this data.

This overview compares 82 powders for .378 Weath. Mag. loaded with the .375 | 270gr | Barnes XLC S. Winchester StaBALL HD delivers the highest muzzle velocity at 3,041 fps; across all powders the maximum-charge window runs from 1,778 fps to 3,041 fps. ADI AR 2217 gives the best case fill at 100 %, and 82 of the 82 powders fall inside the usable 80–100 % fill window.

Relative to the caliber's maximum pressure (440 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 270.0 gr projectile in 0.375" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-23 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 Reloder-26, Accurate MAGPRO, Accurate High Country rank at the top here: for .378 Weath. Mag. with the .375 | 270gr | Barnes XLC S 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.

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