I have a long relationship with Bear Creek Arsenal. I have reviewed many of their products over the years and have been impressed each time. Their approach to building less expensive firearms allows many shooters to buy a rifle who may not otherwise be able to do so. I have found that they pretty much work as advertised.
So, it was with that in mind that I asked them to send me an AR-10 in .277 Sig Fury. Why that oddball caliber?
For the sake of comparison, here is a shot I took of the Fury (center) flanked by the 6.5 Creedmoor (left) and .308 (right).
The .277 Sig Fury… Some History
To put it in a nutshell, it’s the civilian version of the military’s 6.8×51. Initially designed for the Army’s Next Generation Squad Weapons Program by Sig Sauer. The intention was to find a cartridge that could replace the 5.56mm in the M4 carbine and M249 light machine gun.
The cartridge was released in 2019. The military version uses a three-piece case: a steel case head coupled with a brass body, both locked with an aluminum locking washer.
Image: bearcreekarsenal.com
It runs at a chamber pressure of 80,000 psi. When I first read that, I thought it was a misprint, but no, that’s its operating pressure. It was accepted by SAAMI in 2020.
Why did the Army solicit new rifle cartridges for adoption? Short answer: to defeat body armor at 500 yards. The 5.56mm was designed for a different war than what is being fought now. Back when that cartridge made its appearance, individually-worn body armor wasn’t a thing. That is different nowadays, where the prevalence of armor on the battlefield is pretty much a given. So, they wanted to be able to defeat it at that distance. They settled on the .277 Fury, with its hybrid case and 3K velocity.
On April 14, 2022, the Army announced that it had approached Sig Sauer to develop a semi-automatic rifle capable of firing the new cartridge. That became the M7 rifle. A new automatic rifle, the M250, is designed to replace the M249. Sig Sauer offers the M7 to consumers as the MCX Spear, in semi-auto-only trim.
Here is a list of government versions of the new cartridge
- XM1168 General Purpose (Prototype)
- XM1184 Special Purpose
- XM1186 General Purpose, Hybrid
- XM1188 Reduced Range, Hybrid
- XM1192 Blank
Please note that, unless the note says “Hybrid”, that particular cartridge will utilize an all-brass case loaded to lower pressures. The hybrid version will push a 140-grain bullet to 3,000 fps, while its brass-cased version will hit 2750 fps. Also notice the Reduced Range variation… that allows the 6.8×51 (or 6,8 common cartridge, as named by the Army) to be used on existing 5.56mm ranges without tearing up targets.
Performance
I touched on some ballistics info above. Add to that what Sig Sauer claims… that the .277 Fury/6.8×51 has performance that outdoes the 6.5 Creedmoor, with between 6 and 9 feet less bullet drop at 1000 yards, while delivering 20%-25% greater energy. It also outdoes the .308.
Here’s a handy chart I found on Bear Creek Arsenal’s website that gives us some numbers…
| Cartridge | Barrel Length | Bullet Weight | Muzzle Velocity | Energy @ 100y | Energy @ 500y | Drop @ 500y |
| .277 SIG FURY | 16″ | 140gr | 3,000 FPS | 2,529 ft.lbf | 1,654 ft.lbf | -41 inches |
| 6.5 Creedmoor | 24″ | 140gr | 2,710 FPS | 2,056 ft.lbf | 1,317 ft.lbf | -53 inches |
| .300 Win Mag | 26″ | 180gr | 2,960 FPS | 2,947 ft.lbf | 1,378 ft.lbf | -52 inches |
| .308 Winchester | 24″ | 168gr | 2,700 FPS | 2,356 ft.lbf | 1,264 ft.lbf | -59 inches |
| 5.56 NATO | 16″ | 62gr | 2,800FPS | 1,080 ft.lbf | 512 ft.lbf | -54 inches |
Looking at real-world numbers, here’s what I got with my Caldwell Velociradar chrono…
(For some reason, I didn’t catch the fact that I needed to change my zero distance. Zeroing at 600 may work on Mars, but most of us Earthlings like to zero at closer ranges. This is more of an exercise in what this amazing chrono is capable of. It’s the only one I know of that’s affordable for the average shooter and that will break down ballistics at different distances. I really like my Garmin and Athlons, but this one is what I grab when I need downrange ballistics. I just have to remember to change the zero distance…). I intend to do an article on reloading the .277… I’ll reset the chrono and try again. Stay tuned…
Anyway…
The summary. It didn’t quite hit the 2750 mark, but it wasn’t that far off.
Specifications
- Caliber .277 Fury
- Weight (lbs) 7.8
- Barrel Length 16 in.
- Profile M4 Contour
- Twist 1:7
- Barrel Finish Parkerized
- Material 4150 Chrome Moly Vanadium
- MSRP: $505
Where To Buy
Range Time
Here we have the shooting setup, along with a sighter target
As I’ve explained in previous reviews, a tree came down in front of my 100-yard target stand, so I’m down to about 90 yards. I’m working on the full 100. Anyway, you can get a really good idea of how a rifle behaves at 90 yards, so I set up some targets.
I had exactly one type of .277 ammo… the Sig .277 Fury 135-grain JHP. This would equate to the military practice load, so I didn’t feel bad about it being the only load I had. I ordered it from Midway USA… there is zero .277 Fury ammo locally.
OK, so let’s see the target…
Except for it being about an inch left, it would work. The scope did a great job. Speaking of the scope… it is a Hi-Lux Leatherwood ART M1000-PRO 2X-10X42 Rifle Scope. ART stands for automatic ranging trajectory. This scope is really something. It uses an adjustable cam that allows you to set the reticle to bracket your target, and then the holdover is done for you. Just hold typically on the target.
There is a lot of ballistic science involved in setting the scope up that I won’t go into here. Look for a review soon on this and a Hi-Lux red dot. In the meantime, you can go here to read about it. These scopes have military applications for snipers and designated marksmen. They are truly unique.
The trigger was acceptable. It exhibited a 3.5-pound pull weight with minimal take-up and creep.
When you’re done shooting, cleaning is indicated. The MTM Case-Gard Gun Vise helps, as do Real Avid tools and bit set. Even the range bag by Birchwood Casey gets into the act.
Conclusion
For those rifle aficionados looking for something a bit off the beaten path, the .277 Fury is a good dock to tie your boat to. With ballistics out the wazoo – that’s a technical term – and energy/trajectory numbers this side of great, I look for this cartridge to take off. Recoil is there, but not bad, and hunting loads are available. I will be doing a separate article soon on reloading for this new screamer, so be on the lookout.
Is it perfect? Of course not… nothing is. Downsides include ammo availability and cost, and a dearth of rifles chambered in this caliber. There is always the original, the Sig Spear, and a few others. The BCA AR-10 platform performed very well… I did have a couple of magazine issues, but that was most likely due to the magazine that I bought. Do yourself a favor and buy better AR-10 mags, and you will be happy. Also, if I had it to do over again, I’d buy a 10-round mag instead of the 20 I got. The shorter mag sits better on a rifle rest.
For a long-range deer or other game thumper, or for long-range competition, the .277 Fury is surely a contender. Check one out if you fall into this category. It is truly a solid performer.
Links To Items Used In This Review
- MTM Case-Gard High-Low Shooting Table, $160
- Caldwell E-Max Low-Profile Hearing Protectors, $33
- Birchwood Casey Shooting Bags Filled, $40
- Caldwell Velociradar Radar Chronograph, $605
- Bear Creek Arsenal Paper Target, 25 Pack, $10
- Real Avid Pistol Tool, $45
- Real Avid Gun Tool Max, $90
- MTM Case Gard Gun Vise, $60
- Real Avid Smart Drive Screwdriver 90 Bit Set, $110
Read the full article here