Cru Arms Unique AR-180 Based Temp556 Rifle Review

Fighting rifles are steadily evolving and improving. Yes, there are times of stagnation, but the push is steadily forward. The same holds true for their ammunition, optics and accessories. In many respects the optics and accessories are what provides over-match, and can be more important than the rifle you put them on. Yet, it is the rifle itself which remains the key component. One new 5.56x45mm offering is the Temp556 from Cru Arms. Like a host of successful designs the Temp556’s operating system is based off the old ArmaLite AR-18. The rest of the rifle though, is quite different.

I first learned of Cru Arms’ Temp556 rifle through their exclusive distributor, GunZoneDeals.com. Michelle Hamilton and I discussed what we knew about the new offering, and decided it would be interesting to cover. Our original plan was for both of us to test and review the Temp556, but due to circumstances beyond our control, that did not happen. I received a review rifle on short-term loan from Cru Arms for this article, and it will be returned once testing is complete. Neither GunZoneDeals.com nor Cru Arms advertise with Firearms News, it just seemed like an interesting rifle our readers might like learning about.

A Breakdown of the Design

The Cru Arms’ Temp556’s method of operation is gas via a short-stroke piston. This operates a multi-lug carrier controlled rotating bolt. Take down of the bolt carrier assembly is straight-forward and anyone who has stripped an AR-15, or any AR-18 based design, will find it familiar. The bolt carrier assembly rides inside a billet 6061 aluminum monolithic upper receiver. This has a MIL STD 1913 rail machined into the top for easy mounting of iron sights and day/night optical sights. An ambidextrous non-reciprocating charging handle is mounted. Behind the ejection port is a case deflector.

As this is a monolithic design, the handguard is integral to the upper receiver. It features numerous holes and slots to reduce weight. For mounting accessories M-LOK slots are provided at 6 O-clock and another four are provided at 3 and 9 O’clock. One of the slots at 6 O’clock is not usable due to the proximity of the gas blocks sets screws. Inside the handguard is a 16-inch barrel machined from 4150 chrome moly. This features a Nitride finish and a one turn in seven inches rifling twist. Muzzle threads are 1/2x28 TPI and an A2 flash suppressor is standard. The barrel and barrel extension appear to be standard AR-15 pieces and the barrel markings look similar to those found on Bear Creek Arsenal barrels. Cru Arms refers to the gas system as being “Mid-Length” and the gas block diameter is 0.750 inch.  

The lower receiver is machined from billet 6061 aluminum and resembles an AR-15 lower receiver in profile. Like an AR-15, the Temp556’s lower mounts to the upper receiver via two captured cross-pins. The magazine release is a push button in the same position, and a standard AR-15 fire control group and selector are utilized. Rather than the AR-15’s cross-pins though, the Temp556 uses screws to retain the trigger group. Actually, as you look the rifle over you will notice quite a few screws. This is a different design philosophy from say the AK-47 or M16A1. The downside to screws is they can loosen up over time due to firing vibrations. The pistolgrip is another standard AR-15 piece, and a Magpul MOE pistolgrip is fitted. So, the design does use some standard AR-15 pieces, allowing you to easily customize the gun.

Fitted to the left side of the lower receiver is a bolt release, and this is nothing like that found on an AR-15. An odd looking piece, it extends above the safety. It is placed to be in easy reach of the thumb of a right-handed shooter. With the bolt locked back, simply pushing it up and forward to release the bolt. You can manually lock the bolt back by retracting it and pushing the release down and back.

You can also lock the bolt back manually using the charging handle. The charging system of the Temp556 is a bit odd, and one of the features I really do not like about this rifle. The bolt handle is a thin, flat and poorly contoured metal piece which has two points. It is held on by two screws and just seems poorly shaped. The design is similar to an HK roller-lock gun in that it can be retracted and then turned up into a notch to lock the bolt back. This allows you to do the “HK slap” to release it if you so choose. The downside to this is if the bolt locks back on an empty magazine it takes very little force to inadvertently bump the handle up into the hold-back notch. Then, even if the handle is only partially rotated up into the notch, if you depress the bolt release the bolt will be caught by the notch rather than running forward. If this happens you need to slap the handle down out of the notch to get the bolt to run home. On the plus side the handle can be easily swapped from side to side.

To make the Cru Arms Temp556 more compact, it’s fitted with a side-folding/collapsing ACR style buttstock. This can be folded to the left side of the receiver to reduce its over-all length. This is handy, especially in vehicles. It does not lock into place when folded, and does kinda flop around. It can be extended/collapsed through multiple positions to adjust the length of pull. The stock is also fitted with a cheekrest. This can be raised for use with optics or lowered as the user sees fit. A rubber buttpad keeps the butt from sliding around on your shoulder and QD sling sockets are fitted.

Overall length of the rifle with the stock fully extended is 36.5 inches and with it fully collapsed it measures 33.6 inches. Folding the stock drops the length to just 26.75 inches. The Cru Arms Temp556 weighs in at 9 pounds and is available with a Flat Dark Earth or black finish. While Cru Arms lists the Temp556’s weight at 8.1 pounds, it feels much heavier. I weighed it on two scales, with no mag or accessories, and it came in at 9 pounds. It is noticeably front heavy, and really needs to be put on a diet. Mounting an optic, adding a sling and inserting a loaded 30-round magazine can easily push the weight up over 11 pounds. Feed is from standard M16 pattern STANAG magazines and it comes with one 30-round Magpul PMAG magazine.

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In the Hands

Hefting it I noted the Temp556 feels heavy with the balance point towards the front. Basically, it handles like a 1971 Dodge Polara on skinny belted bias-ply tires. Get it moving in one direction and it takes some effort to point it in another. The controls are all easy to reach, the stock folds with the push of a button and the buttplate is substantial. One nice feature is the ability to lock the bolt back while maintaining a firing grip. However, not all will like the charging handle. Also, due to its location, it’s very easy to smack your hand against your optic’s mount when operating it. The trigger is heavy, and crunches along.  

Checking Accuracy

For the accuracy portion of testing I mounted a Vortex 6-36x56mm Razor HD Gen III scope using a Geissele Super Precision 34mm mount. The big Vortex is an impressive optic. The new Razor’s magnification zooms all the way to 36x on the top end, while zooming out to just 6x on the low end. The turrets are big, easy to zero and feature .1 Mil adjustments with 10 Mils per full turret rotation. The adjustments are precise with distinct audible and tactile clicks. An external rotation indicator provides both visual and tactile reference of which rotation the turret is on. The design features locking turrets, a smooth operating mechanism block mounted parallax adjustment and an illuminated reticle. This particular scope was fitted with the EBR-7D reticle design delineated in Mils. A First Focal Plane design, the reticle sports a very fine center dot and hold points for elevation and windage/lead. All in all this is a workhorse of a scope which has become my favorite for accuracy testing.

Initial testing was done from the bench at 100 yards with four consecutive five round groups fired with each load. Test ammunition consisted of Black Hills Ammunition’s .223 Rem 69-grain Matchking and their well-respected 5.56x45mm 77-grain Tipped Matchking match loads, Hornady’s well-respected 5.56x45mm 75-grain TAP BTHP-WC T2 load, and Australian Outback’s .223 Rem 55-grain Blitzking load. Velocity readings were recorded 12 feet from the muzzle with a LabRadar Doppler chronograph at an ambient temperature of 85 degrees F at 1,130 feet above Sea Level.

The rifle zeroed easily and I was soon firing for record. I quickly noticed a few things. Thanks to the rifle’s weight, it is very smooth shooting. It’s a very comfortable rifle to fire. However, the trigger is very heavy and it was very sluggish when it came to resetting. Lastly, it seemed to favor lighter weight bullets. Best accuracy was obtained using Australian Outback’s 55-grain Blitzking load. This did not particularly surprise me, as I’ve had excellent luck with this load. The Cru Arms Temp556 proved capable of putting 3 or 4 rounds into a tight .5-inch knot before I dropped one or two. This load averaged a respectable 1 inch at 2,923 fps. Black Hills Ammunition’s 69-grain Matchking load averaged 1.9 inches at 2,699 fps. Hornady’s 75-grain TAP T2 load averaged 2 inches at 2,741 fps. Black Hills Ammunition’s 77-grain Tipped Matchking load was not to the Temp556’s liking and averaged a disappointing 2.5 inches at 2,751 fps. While very pleasant to shoot, this rifle’s trigger was not an aid to shooting tight little groups.

Up Close with an ELCAN 

Stripping the big Vortex off, I next mounted a 4x ELCAN SpecterOS4x and ran some drills from 7 to 280 yards. This model ELCAN is a fixed 4x scope which performs well. Controllability on rapid fire proved very good with a recoil pulse different than a standard 16-inch AR carbine. The rifle’s weight certainly helped in this regard. Magazines ejected cleanly and the Temp556 proved easy to run. Reliability was good, with one failure to eject. This was a bit odd, as it was the last round of a magazine and the fired case was held by the locked back bolt. That was the only malfunction experienced through-out testing. Otherwise ejection was fine, and towards 3 O-clock.

The Temp556 proved easily capable of routinely hitting a full-size Action Target silhouette at 280 yards from various field positions. I shot it offhand, kneeling, sitting and prone. Shooting prone off the mag at this distance simply rang the steel in rapid succession. Thirty rounds of Black Hills 69-grain Matchking match fired at a rapid rate prone off the mag all grouped into the center of the silhouette’s chest.

Final Thoughts

Without a doubt Cru Arms’ Temp556 is an interesting 5.56x45mm carbine. Accuracy was surprising with Australian Outback’s 55-grain Blitzking load. The controls are well laid but I do not like the charging handle. MLOK slots and the M1913 rail allow a variety of accessories to be easily mounted. The stock is easily adjusted and comfortable. Finally, field stripping the Temp556 is straight-forward. Downside is the weight and how it balances. The trigger is very heavy too. Is the Cru Arms Temp556 for everyone? No, but its lines and “not being an AR-15” will certainly appeal to some. Price is $1,799 so it is not overly expensive, but not economical either. It’s also interesting to note that it’s legal to own in Canada. If you have the AR and AKs blahs, maybe you’ll find the Cru Arms Temp556 appealing. If so, it is available through GunZoneDeals.com.

Cru Arms Temp556 Specs

• Type: Short-stroke gas with rotating bolt
• Caliber: 5.56x45mm NATO
• Barrel: 16-in. 4150 chrome moly. Nitride finish with 1-7-in twist
• Feed: AR-15 type detachable box magazine
• Weight: 9 lbs. without mag
• Overall Length: 36.5 in. with stock fully extended, 26.7 in. with stock folded
• Sights: None
• Price: $1,799

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About the Author

David M. Fortier has been covering firearms, ammunition and optics since 1998. He is a recipient of the Carl Zeiss Outdoor Writer of the Year award and his writing has been recognized by the Civil Rights organization JPFO. In 2007, he covered the war in Iraq as an embedded journalist. He has written extensively on opposing forces small arms, ammunition and optics and has traveled through Russia, Europe, the Middle East, and South America. His writing has been translated into both Russian and Mandarin. He was a regular on the Outdoor Sportsman Group’s network television from 2003 to 2020. He is currently the Editor of the Outdoor Sportsman Group prepping title Be Ready! magazine, as well as the Executive Editor of Firearms News. Prior to 1998, he was in the Aerospace and Defense industry.

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