Seventy seven grains is as heavy as factory 5.56 NATO gets, and the weight buys reach rather than raw speed. Below, two proven 77 gr match loads are charted shot by shot out to 500 yards, followed by the published factory data for the full set of 77 gr loads held in the stored library.
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5.56 77gr Ballistics Chart
| Load | Bullet | Traj. Zero | Velocity Muzzle (fps) | Velocity 100 (fps) | Velocity 200 (fps) | Velocity 300 (fps) | Velocity 400 (fps) | Velocity 500 (fps) | Trajectory 100 yd (in) | Trajectory 200 yd (in) | Trajectory 300 yd (in) | Trajectory 400 yd (in) | Trajectory 500 yd (in) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 77 gr Sierra MatchKing | Sierra MatchKing HPBT | 100 yd | 2720 | 2478 | 2249 | 2032 | 1828 | 1639 | 0 | -4.2 | -15.3 | -34.8 | -64.8 |
| Mk 262 Mod 1-C | Sierra Tipped MatchKing (TMK) | 200 yd | 2750 | 2520 | 2295 | 2070 | 1870 | 1685 | 2 | 0 | -8.5 | -25 | -52 |
Above: the speed and flight path of both charted loads across 500 yards, each printed on its own zero.
Speed Downrange
Starting at 2,720 fps, the Sierra MatchKing load slows to 2,478 fps at 100 yards, 2,032 fps at 300 yards and 1,639 fps at 500 yards. The Mk 262 Mod 1-C opens at 2,750 fps out of a 20 inch barrel and reaches 500 yards at 1,685 fps. Both bullets are still moving fast at the far end of the chart, which is exactly the point of the heavyweight class.
Energy Retention
Downrange energy separates the 77 grain class from lighter 5.56 loads. Figures for the MatchKing load read 1,050 ft-lb at 100 yards and 459 ft-lb at 500 yards. The Tipped MatchKing load records 1,293 ft-lb at the muzzle, 931 ft-lb at 200 yards, 654 ft-lb at 400 yards and 542 ft-lb at 500 yards. A ballistic coefficient of 0.420, well above the MatchKing’s 0.372, drives that retention.
Reading the Flight Path
Zero choice shapes every trajectory figure in the chart. With a 100 yard zero, the MatchKing prints 0.0 inches at 100 yards, minus 15.3 inches at 300 yards and minus 64.8 inches at 500 yards. Set up on a 200 yard zero, the Mk 262 prints plus 2.0 inches at 100 yards, level at 200 yards, minus 8.5 inches at 300 yards and minus 52.0 inches at 500 yards.
Behaviour in Wind
Crosswind push stays modest for a bullet of this weight and shape. The Tipped MatchKing load moves 0.8 inches at 100 yards in a 10 mph crosswind, 3.3 inches at 200 yards, 14.4 inches at 400 yards and 23.5 inches at 500 yards. Shooters stretching a 5.56 to its limits lean on that stability shot after shot.
Published Factory Data for 5.56 77 Grain Loads
Three loads out of the sixteen stored factory 77 gr offerings arrive with complete factory tables, reproduced below in the makers’ own figures and units: velocity in feet per second, energy in foot pounds and trajectory in inches. Winchester prints the same numbers for its Match and Super Match lines, both on a 200 yard zero. Magtech’s 556C load is printed on a 100 yard zero from a 20 inch test barrel, with the 100 yard trajectory listed as 0.001 and rounded to 0.0 here.
| Brand | Load | SKU | Bullet Style | BC (G1) | Test Barrel | Traj. Zero | Velocity Muzzle (fps) | Velocity 100 (fps) | Velocity 200 (fps) | Velocity 300 (fps) | Velocity 400 (fps) | Velocity 500 (fps) | Energy Muzzle (ft-lb) | Energy 100 (ft-lb) | Energy 200 (ft-lb) | Energy 300 (ft-lb) | Energy 400 (ft-lb) | Energy 500 (ft-lb) | Trajectory 100 yd (in) | Trajectory 200 yd (in) | Trajectory 300 yd (in) | Trajectory 400 yd (in) | Trajectory 500 yd (in) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Magtech | 5.56X45mm HPBT 77GR Cannelured | 556C | Sierra Cannelured HPBT | 0.362 | 20 inch | 100 yd | 2790 | 2541 | 2305 | 2081 | – | – | 1331 | 1104 | 908 | 741 | – | – | 0 | -5.4 | -17.4 | – | – |
| Winchester | 5.56mm, 77 Grain | S556M | Match BTHP | 0.34 | – | 200 yd | 2750 | 2488 | 2240 | 2007 | 1789 | 1589 | 1293 | 1058 | 858 | 689 | 547 | 432 | 2.1 | 0 | -9 | -26.7 | -55.3 |
| Winchester | 5.56mm, 77 Grain | SM556 | Boattail Hollow Point (BTHP) | 0.34 | – | 200 yd | 2750 | 2488 | 2240 | 2007 | 1789 | 1589 | 1293 | 1058 | 858 | 689 | 547 | 432 | 2.1 | 0 | -9 | -26.7 | -55.3 |
Muzzle Only Listings
The remaining thirteen factory loads are sold with muzzle figures and nothing further, so they appear in the short table below rather than in rows full of gaps. HSM’s pair of Match loads lead on 2,867 fps and 1,406 ft-lb, Grizzly and Liberty sit at 2,800 fps, seven loads share 2,750 fps, AAC’s three loads show 2,700 fps, and Norma’s MLE load closes the list at 2,650 fps with a healthy 1,350 ft-lb at the muzzle.
| Brand | Load | SKU | Muzzle Velocity (fps) | Muzzle Energy (ft-lb) |
|---|---|---|---|---|
| AAC | 5.56 NATO 77 Grain OTM | AAC556OTM1-20 | 2700 | – |
| AAC | 5.56 NATO 77 Grain Sierra MatchKing HPBT | AAC556SMK1-20 | 2700 | – |
| AAC | 5.56 NATO 77 Grain Sierra TMK | AAC556TMK1-20 | 2700 | – |
| Atomic Ammunition | 5.56 NATO 77gr Cycling HP BT Defense | CART-77GR-CYCL-HPBT-DEF | 2750 | 1294 |
| Black Hills | 77 Gr. MK 262 MOD 1-C | – | 2750 | 1293 |
| Black Hills | 77 Gr. Open Tip Match | – | 2750 | 1293 |
| Black Hills | 77 Gr. Sierra TMK | – | 2750 | 1293 |
| Grizzly Cartridge Co. | 5.56x45MM 77gr OTM | GCM-3 | 2800 | 1340 |
| HSM Ammunition | 5.56x45mm 77gr | HSM-556-18T-N | 2867 | 1406 |
| HSM Ammunition | 5.56x45mm 77gr | HSM-556-9-N | 2867 | 1406 |
| Liberty Ammunition | 5.56 NATO 77 gr Overwatch | LA-OW5.56-074 | 2800 | – |
| Norma | NORMA MLE 5.56X45 77GR OTM | 601701234 | 2650 | 1350 |
| SIG Sauer | Elite Match Grade OTM 77 gr | E556M4-20 | 2750 | 1293 |
Frequently Asked Questions
What muzzle speeds do factory 5.56 77 gr loads produce?
The stored factory loads span 2,650 fps to 2,867 fps. The two charted match loads leave at 2,720 fps and 2,750 fps.
How far does a 77 gr 5.56 bullet fall by 500 yards?
On a 100 yard zero the charted MatchKing is down 64.8 inches at 500 yards. On a 200 yard zero the Mk 262 Mod 1-C is down 52.0 inches at that range.
What energy remains at 500 yards?
The Tipped MatchKing load keeps 542 ft-lb at 500 yards, and the MatchKing load keeps 459 ft-lb. Both figures sit well above what lighter 5.56 bullets retain at that distance.
What makes the Mk 262 Mod 1-C different?
It is Black Hills’ military pattern 77 grain match load, rated at 2,750 fps with a Tipped MatchKing bullet in the charted version. Its table is printed on a 200 yard zero from a 20 inch barrel.
What ballistic coefficients are printed for 77 gr loads?
The printed range runs from 0.340 on Winchester’s two match loads up to 0.420 on the Tipped MatchKing. Magtech’s load prints 0.362 and the Sierra MatchKing prints 0.372.
Which 5.56 77 gr factory load leaves the muzzle fastest?
HSM’s Match loads, at 2,867 fps and 1,406 ft-lb. Grizzly Cartridge Co. and Liberty Ammunition follow at 2,800 fps.
Does a 77 gr bullet stay supersonic at long range?
Yes. The MatchKing load is still supersonic beyond 600 yards, and its published figures run out to 1,000 yards, where it records 1,022 fps.
Why is the Mk 262 high at 100 yards in the chart?
Its table uses a 200 yard zero, so the bullet is still climbing at 100 yards and prints 2.0 inches high. The MatchKing table uses a 100 yard zero and prints 0.0 inches at that distance.
How many factory 77 gr loads publish a full table?
Three of the sixteen stored loads: Winchester’s S556M and SM556, plus Magtech’s 556C. Every other stored load stops at muzzle velocity and, in most cases, muzzle energy.
Why choose a 77 gr load over a 55 or 62 gr load?
The heavier match bullet trades a slower start for a higher ballistic coefficient. In practice that means more retained velocity and energy, less wind drift and a longer supersonic reach.