Published: December 2025 | Last updated: April 2026
The 277 Fury (6.8x51mm) was developed by SIG Sauer for the U.S. Army’s Next Generation Squad Weapon program, adopted in 2022 as the XM5 rifle cartridge. It represents a genuinely new approach to cartridge design: a hybrid case combining a brass body with a stainless steel base capable of handling chamber pressures up to 80,000 PSI – approximately 35-40% higher than SAAMI maximum for standard commercial cartridges like the 308 Winchester. That extreme pressure is what enables the 277 Fury to push 135-grain bullets to 3,000 FPS from a 16-inch barrel – matching the muzzle energy of the 300 Winchester Magnum from a significantly lighter, shorter package.
The civilian 277 Fury operates at reduced pressure compared to the military specification, but still reaches approximately 60,000-65,000 PSI – higher than any standard hunting cartridge. This pressure level is what produces its ballistic performance, and it is also the cartridge’s defining limitation: only rifles specifically engineered for the 277 Fury’s pressure can be used.
Critical safety warning: The 277 Fury‘s 80,000 PSI military specification (and 60,000+ PSI civilian specification) exceeds the safe operating pressure of all standard hunting rifles. Do not attempt to chamber 277 Fury ammunition in any rifle not specifically manufactured and marked for this cartridge. Rifles in 270 Winchester, 270 WSM, or any other 27-caliber chambering are not safe for 277 Fury ammunition. Only purpose-built rifles from SIG Sauer, Seekins Precision, Barrett, Savage, and other manufacturers who specifically engineer their actions for 277 Fury pressures are appropriate.
For reloading data, see the 277 Fury complete guide, brass care guide, and best bullets guide. For comparisons, see 277 Fury vs 6.5 PRC.
Core Ballistic Parameters
| Load | MV (16″ barrel) | BC (G7) | Muzzle Energy |
|---|---|---|---|
| 113 gr SIG Hunter | 3,200 FPS | 0.224 | 2,570 ft-lbs |
| 135 gr Hornady ELD-M | 3,000 FPS | 0.278 | 2,699 ft-lbs |
| 140 gr Hornady ELD-X | 2,985 FPS | 0.315 | 2,771 ft-lbs |
| 150 gr Sierra MatchKing | 2,850 FPS | 0.315 | 2,706 ft-lbs |
All data below uses a 100-yard zero, 1.5-inch sight height, 59°F, sea level. The 277 Fury is a general hunting and military cartridge. A 100-yard zero is the practical standard.
Bullet Drop (100-Yard Zero)
| Range (yards) | 113 gr | 135 gr | 140 gr | 150 gr |
|---|---|---|---|---|
| Muzzle | -1.5 | -1.5 | -1.5 | -1.5 |
| 100 | 0.0 | 0.0 | 0.0 | 0.0 |
| 200 | -2.5 | -2.9 | -2.9 | -3.3 |
| 300 | -9.2 | -10.4 | -10.2 | -11.5 |
| 400 | -21.0 | -23.5 | -23.0 | -25.9 |
| 500 | -38.0 | -42.5 | -41.5 | -46.5 |
| 600 | -61.5 | -68.0 | -66.5 | -74.5 |
| 700 | -91.5 | -101.0 | -98.5 | -110.5 |
| 800 | -130.0 | -143.5 | -139.5 | -156.5 |
| 900 | -177.5 | -196.0 | -190.0 | -213.5 |
| 1,000 | -235.0 | -260.0 | -251.5 | -282.0 |
Drop in inches. Zero at 100 yards.
The 277 Fury’s trajectory is genuinely impressive at its design pressure. The 113-grain load at 3,200 FPS from a 16-inch barrel produces drop figures competitive with the 6.5 Creedmoor from a longer bolt-action barrel. At 500 yards the 113-grain drops 38 inches with a 100-yard zero – approximately 6-7 inches less than a 308 Winchester 168-grain load at the same zero.
The 140-grain ELD-X shoots 2 inches flatter than the 150-grain MatchKing at 500 yards despite identical BC (G7: 0.315), because its 135 FPS starting velocity advantage compounds over distance. At 1,000 yards the gap grows to 30 inches – the 140-grain’s velocity advantage matters increasingly at long range.
The 113-grain’s dramatically flat trajectory makes it the choice for unknown-distance shooting inside 400 yards. At 400 yards it is only 21 inches low versus 26 inches for the 150-grain – nearly a full vital zone width of difference that simplifies holdover estimates in the field.
Wind Drift – 10 MPH Full-Value Crosswind
| Range (yards) | 113 gr | 135 gr | 140 gr | 150 gr |
|---|---|---|---|---|
| 100 | 0.6 | 0.6 | 0.5 | 0.6 |
| 200 | 2.4 | 2.4 | 2.2 | 2.5 |
| 300 | 5.6 | 5.6 | 5.1 | 5.7 |
| 400 | 10.2 | 10.2 | 9.2 | 10.5 |
| 500 | 16.5 | 16.5 | 14.9 | 17.0 |
| 600 | 24.5 | 24.3 | 22.0 | 25.0 |
| 700 | 34.0 | 33.7 | 30.5 | 34.7 |
| 800 | 45.5 | 45.0 | 40.8 | 46.5 |
| 900 | 59.0 | 58.0 | 52.8 | 60.0 |
| 1,000 | 74.5 | 73.5 | 66.5 | 76.0 |
Drift in inches. Half-value crosswind = divide by 2.
The wind drift table reveals an important practical distinction between loads. The 140-grain ELD-X drifts approximately 7-9 inches less than the 113-grain and 150-grain at 1,000 yards – reflecting its superior BC-to-velocity ratio. The 140-grain’s G7 BC of 0.315 combined with its 2,985 FPS starting velocity produces a better result than either the fast-but-low-BC 113-grain or the heavy-but-slow 150-grain.
Notably, the 113-grain and 135-grain loads drift nearly identically at all distances despite the 113-grain’s higher velocity, because the 135-grain’s better BC (G7: 0.278 vs 0.224) compensates for its 200 FPS velocity deficit. This BC-velocity balance is a recurring theme in 277 Fury load selection: the highest velocity does not automatically produce the best wind resistance past 600 yards.
Velocity Retention
| Range (yards) | 113 gr | 135 gr | 140 gr | 150 gr |
|---|---|---|---|---|
| Muzzle | 3,200 | 3,000 | 2,985 | 2,850 |
| 100 | 2,914 | 2,773 | 2,789 | 2,651 |
| 200 | 2,641 | 2,556 | 2,600 | 2,460 |
| 300 | 2,380 | 2,347 | 2,418 | 2,276 |
| 400 | 2,132 | 2,145 | 2,241 | 2,098 |
| 500 | 1,897 | 1,951 | 2,070 | 1,927 |
| 600 | 1,675 | 1,764 | 1,905 | 1,763 |
| 700 | 1,467 | 1,585 | 1,746 | 1,606 |
| 800 | 1,276 | 1,415 | 1,593 | 1,456 |
| 900 | 1,104 | 1,256 | 1,448 | 1,315 |
| 1,000 | 954 | 1,109 | 1,310 | 1,184 |
Velocity in FPS. Supersonic threshold approximately 1,340 FPS at sea level.
The velocity retention crossover is pronounced with the 277 Fury. The 113-grain starts 350 FPS faster than the 150-grain but its lower BC means the 150-grain is actually faster by 400 yards. The 140-grain ELD-X – with the best BC-to-velocity combination – stays fastest from 400 yards onward. By 900 yards the 140-grain at 1,448 FPS is still comfortably supersonic while the 113-grain at 1,104 FPS is approaching subsonic.
The 113-grain goes transonic around 925-950 yards. The 135-grain goes transonic near 975 yards. The 140-grain and 150-grain both stay supersonic past 1,000 yards, with the 140-grain providing more supersonic margin (1,310 FPS at 1,000 yards vs 1,184 FPS for the 150-grain).
Important context for 16-inch barrel data: a 20-inch barrel adds approximately 75-100 FPS to all loads, extending supersonic range by 50-75 yards. A 24-inch barrel adds approximately 125-175 FPS. The velocity figures above reflect the standard 16-inch barrel configuration for the 277 Fury.
Energy Retention
| Range (yards) | 113 gr | 135 gr | 140 gr | 150 gr |
|---|---|---|---|---|
| Muzzle | 2,570 | 2,699 | 2,771 | 2,706 |
| 100 | 2,128 | 2,304 | 2,416 | 2,340 |
| 200 | 1,749 | 1,959 | 2,103 | 2,015 |
| 300 | 1,421 | 1,651 | 1,817 | 1,726 |
| 400 | 1,141 | 1,381 | 1,561 | 1,468 |
| 500 | 903 | 1,141 | 1,332 | 1,237 |
| 600 | 703 | 934 | 1,128 | 1,034 |
| 700 | 540 | 754 | 946 | 858 |
| 800 | 408 | 600 | 789 | 707 |
| 900 | 306 | 472 | 651 | 576 |
| 1,000 | 228 | 369 | 533 | 467 |
Energy in ft-lbs.
The energy picture is where the 277 Fury’s high-pressure design justifies itself most clearly. The 140-grain ELD-X holds above 1,500 ft-lbs (elk threshold) to approximately 450-460 yards – competitive with the 300 Winchester Magnum in a rifle that weighs significantly less and generates substantially less recoil. For deer (1,000 ft-lbs threshold), the 140-grain holds above that mark past 650 yards.
The 113-grain drops below 1,500 ft-lbs around 375-390 yards and below 1,000 ft-lbs around 490-500 yards. For elk, the 113-grain is a 350-yard load at best. The 150-grain holds above 1,500 ft-lbs to approximately 420-430 yards.
The original article’s energy commentary noted that “heavier bullets retain energy more effectively due to mass” – this is true here because the 140 and 150-grain loads start with both more velocity and more mass than the 113-grain. The 140-grain’s superior BC-to-velocity combination makes it the best energy-retaining load at all distances past 200 yards.
Terminal Performance Profiles
SIG Sauer Hybrid Hunter 135 gr
Construction: SIG’s purpose-built 277 Fury hunting load using a bonded polymer-tipped bullet specifically engineered for the cartridge’s extreme velocity. The bonded core is essential at 277 Fury’s 3,000+ FPS velocities where cup-and-core bullets can fail.
Terminal behavior: Expands to 0.52-0.60 inches with 60-70% weight retention. At 3,000 FPS close-range impact, the bonded core prevents premature jacket-core separation that destroys unbonded bullets at this velocity level. Penetration in elk-sized tissue: 18-24 inches. At 400 yards where velocity drops to approximately 2,145 FPS, expansion is controlled and reliable.
Hunting application: Deer, elk, and black bear inside 500 yards. The 135-grain Hybrid Hunter is SIG’s factory hunting load specifically designed for the 277 Fury’s velocity and pressure characteristics. At 500 yards it delivers 1,141 ft-lbs – adequate for deer on clean shots. On elk, the energy at 400 yards (1,381 ft-lbs) approaches the hunting threshold. Use this load inside 400 yards for elk with broadside shots.
More details: Hornady ELD-X bullet profile
Hornady ELD-X 140 gr
Construction: Polymer tip with Heat Shield, bonded core. At 277 Fury velocities of 2,985 FPS, the ELD-X is at the upper end of its expansion velocity design range – the bonded construction is required to prevent premature core-jacket separation.
Terminal behavior: Expands to 0.54-0.64 inches with 90-95% weight retention at 277 Fury impact velocities. At close range (2,985 FPS), expansion is rapid but controlled due to the bonded construction. At 400 yards (approximately 2,241 FPS), expansion is more moderate and penetration deeper. Penetration in elk-sized tissue: 20-26 inches.
Hunting application: The best all-range 277 Fury hunting load for deer and elk. Energy above 1,500 ft-lbs past 450 yards for elk; above 1,000 ft-lbs past 650 yards for deer. The ELD-X’s superior BC (G7: 0.315) produces the best wind resistance and energy retention of the four loads, making it the practical choice for hunters who want maximum effective range from the 277 Fury.
More details: Hornady ELD-X bullet profile
Nosler Partition 150 gr
Construction: Dual-core partitioned design. The Partition’s velocity-insensitive terminal performance makes it appropriate for the 277 Fury’s extreme close-range velocities – the partition stops expansion and retains the rear core regardless of impact velocity.
Terminal behavior: Front core expands to 0.50-0.60 inches. The partition retains the rear core for an additional 14-18 inches of penetration. Total penetration in elk-sized tissue: 20-28 inches. Weight retention 65-72%. The Partition exits on virtually all deer and most elk broadside shots. At 2,850 FPS close-range impact, the front core expands dramatically; the partition handles the rest.
Hunting application: Elk and black bear inside 400 yards, especially for close-range encounters in timber where impact velocity is at or near maximum. The Partition’s guaranteed rear-core penetration handles extreme close-range impacts at 277 Fury velocities that destroy standard cup-and-core bullets. For guides and hunters who may need to stop a charging or wounded elk at 30 yards, the Partition provides more reliable penetration than expanding bullets that can fail catastrophically at full 277 Fury velocity.
More details: Nosler Partition bullet profile
Barnes TTSX 125 gr
Construction: All-copper expanding bullet with polymer tip, lead-free, 100% weight retention. Monolithic copper survives the 277 Fury’s extreme impact velocities without the core-jacket separation that destroys cup-and-core bullets.
Terminal behavior: Expands to four petals, 0.50-0.58 inches expanded diameter. Full weight retained after expansion – 125 grains of copper continuing forward. Penetration 22-30 inches in elk-sized tissue. Exit wounds are routine on deer; common on elk from broadside shots. The TTSX’s 100% weight retention maximizes momentum transfer at any impact velocity.
Hunting application: Lead-free hunting in California and other regulated states. Also the choice for hunters who require guaranteed exit wounds for tracking or who hunt in areas with stone-hard ground where exiting bullets can create safety hazards. At 277 Fury velocities, the TTSX is one of the most reliable terminal performers because its solid copper construction is indifferent to impact velocity.
More details: Barnes TTSX bullet profile
Federal Fusion 140 gr
Construction: Electrochemically bonded core. The bonding is required at 277 Fury velocities to prevent the core-jacket separation that destroys unbonded bullets. Federal’s process produces a molecularly bonded interface that handles extreme impact velocities.
Terminal behavior: Expands to 0.52-0.62 inches with 85-95% weight retention. Penetration in deer-sized tissue: 18-22 inches. The bonded construction provides reliable terminal performance from close-range 2,985 FPS impacts through extended-range lower-velocity impacts at 400+ yards.
Hunting application: Deer and hogs inside 450 yards. The Federal Fusion 140-grain provides bonded performance at a lower price point than the SIG Hybrid Hunter factory load. For hunters who handload the 277 Fury and want a bonded bullet with verified performance at these pressure and velocity levels, the Fusion is the cost-accessible option.
More details: Federal Fusion bullet profile
Practical Range Recommendations
Deer – 140-grain ELD-X inside 600 yards. Energy holds above 1,000 ft-lbs past 650 yards. The 277 Fury is a genuine 500-yard deer cartridge with energy margin to spare. A 500-yard self-imposed limit in variable field conditions provides adequate margin.
Elk – 140-grain ELD-X or Nosler Partition inside 450 yards. Energy at 450 yards (approximately 1,500 ft-lbs) meets the practical elk threshold. For close-range elk encounters where impact velocity exceeds 2,700 FPS, the Partition provides the most reliable penetration. For 300-450 yard shots where velocity has dropped to a more manageable 2,200-2,500 FPS, the ELD-X is the better choice.
Bonded bullet requirement at all ranges: At 277 Fury velocities, cup-and-core bullets (Core-Lokt, Power-Point, standard soft points) are not reliable choices. Standard cup-and-core bullets were designed for velocities in the 2,700-3,000 FPS range. At the 277 Fury’s 2,985-3,200 FPS, core-jacket separation can occur before the bullet reaches the vitals, particularly at close range. Use only bonded, partitioned, or monolithic copper bullets in the 277 Fury for any hunting application.
Hybrid case handling: The 277 Fury’s hybrid case (brass body, steel base) requires specific handling in the reloading room. Steel-based cases require more force to resize than all-brass cases. Carbide sizing dies reduce friction. See the 277 Fury brass care guide before beginning to handload.
Frequently Asked Questions
Can I shoot 277 Fury ammunition in a standard 270 Winchester or 270 WSM rifle? Absolutely not. The 277 Fury operates at 60,000-80,000 PSI – far beyond the safe operating pressure of any standard hunting rifle action including 270 Winchester (54,000 PSI max) and 270 WSM (65,000 PSI max). The cartridge physically fits in some chambers due to similar bore diameter, which makes this a genuine safety risk. Only rifles specifically manufactured and marked for 277 Fury are safe to use.
What is the civilian vs military pressure difference? Military 277 Fury (XM5/M5) loads reach 80,000 PSI – engineered for the SIG XM5 military rifle’s purpose-built action. Civilian 277 Fury ammunition is loaded to approximately 60,000-65,000 PSI, which is still higher than any standard SAAMI hunting cartridge but within the design envelope of civilian-rated 277 Fury rifles. Never use military surplus 277 Fury ammunition in a civilian rifle.
Why does the 277 Fury need a hybrid brass-steel case? At 80,000 PSI, the forces on the cartridge case head are beyond what standard brass can reliably withstand across repeated firings. The stainless steel base provides the strength needed at the pressure-bearing end of the case while the brass body provides the ductility needed for consistent extraction and chamber seal. This hybrid construction is what enables the cartridge’s extreme pressure specification.
Is the 277 Fury worth the premium over the 6.5 PRC for elk hunting? The 277 Fury produces approximately 200-300 ft-lbs more muzzle energy than the 6.5 PRC with comparable bullet weights. At 400 yards the 277 Fury 140-grain delivers approximately 1,561 ft-lbs versus the 6.5 PRC 143-grain’s approximately 1,550 ft-lbs – essentially equal. The 6.5 PRC provides comparable elk energy at substantially lower ammunition cost, broader factory ammunition selection, and standard rifle compatibility. The 277 Fury’s advantages are its AR-10 platform compatibility and its performance from shorter 16-inch barrels. For a hunter who wants a lightweight AR-10 elk rifle rather than a bolt-action, the 277 Fury is a compelling choice. See 277 Fury vs 6.5 PRC for full analysis.
What rifles are available in 277 Fury? SIG Sauer produces the MCX-SPEAR (military derivative) and Cross bolt-action. Seekins Precision offers the Havak in 277 Fury. Barrett and Savage have offered this chambering. The selection is significantly more limited than mainstream hunting cartridges. Factory ammunition is available from SIG Sauer and a limited number of other manufacturers. Handloading components (bullets, primers, powder) are available in standard form; SIG Fury brass is available from SIG Sauer directly.
How does recoil compare to similar-energy cartridges? The 277 Fury produces approximately 20-22 ft-lbs of recoil energy in a 9-pound rifle with a 140-grain load – comparable to the 7mm Remington Magnum and noticeably less than the 300 Winchester Magnum at 26-28 ft-lbs. In an AR-10 platform with a muzzle brake, recoil is significantly reduced further. The gas-operated semi-auto action spreads recoil over a longer time period than a bolt-action, making the 277 Fury in the MCX-SPEAR or similar platform substantially more comfortable to shoot than equivalent bolt-action magnum cartridges.
Editorial note: This article was originally published in December 2025 and revised in April 2026. The revision added the critical safety warning about 277 Fury chamber requirements at the article top, added G7 BC values and recalculated all ballistic tables using accurate velocity-BC combinations, added velocity retention table showing the BC crossover point where higher-BC slower loads overtake lighter faster loads, added the bonded bullet requirement for all hunting applications, added the hybrid case reloading note, replaced Sierra GameKing (inadequate for 277 Fury velocities) with Federal Fusion 140 gr as a more practical fourth hunting option, replaced SIG hunter note with Barnes TTSX 125 gr as a fifth profile for lead-free requirements, and added FAQ section.
