The below is an INCOMPLETE writeup on the NGA X7.  However it will give you some idea of the level of attention that every single part on the gun received.

Dimensions
OAL stock closed:        31.25”
OAL Stock open:        34.5”
Barrel Length:            14.5”, 16.1” w/ pinned muzzle device
Magwell fore/aft - outside:    ~2.80”
Magwell lateral - outside:    ~1.42”
Hanguard height:        ~2.25”
Handguard width - smooth:    ~1.75”
Hadguard width - rail section:    ~2.25”
Hanguard width - barrel nut:    ~2.22”
Hanguard length:        10.375”
Weight - no sights:        6 lbs 13 oz.
Weight - +Troy sights:    6 lbs 15 oz (Troy Industries front and rear folding sights)
Weight - above +R1:        7 lbs 4.2 oz (Aimpoint R-1 optic mounted on Larue LT660 mount)
Weight - above +IWC Stop:    7 lbs 5.8 oz (IWC Mount N Slot Weapon Control hand stop)
Weight - above +X300:    7 lbs 9.3 oz (Surefire X300)
Weight - above +30 rounds:    8 lbs 10.3 oz (Federal XM193 in Magpul Pmag)


Muzzle Device
Description
The stainless steel muzzle device on the X7 is a unique part to this gun, was designed by Next Generation Arms who defines it as a “compensator” and offers a unique aesthetic.  The design for the 14.5” long barrel is reported as being tuned for that barrel and the version for the 16” tuned for that length.  It is pinned in place on the 14.5” barrel and removable on the 16”.  Wrench flats are sized for a ¾” wrench but only offer ⅛” of width for a wrench to fit in.  OAL is 2.25” and OD is 0.88”.  There are essentially two chambers, one with a stylized slot on each side and one with a series of compound-curved tines.  The first chamber is ~0.75” long with a baffle on one end with a ~0.25” hole.  The curved tines extend from this baffle ~0.34”.  Entire devices is ceramic coated in black.

Advantages
NGA terms the device a “compensator” and their stated intent is to achieve “muzzle neutrality”, or to reduce muzzle climb.  This would indicate that their design is intended more on the “brake” side than the “flash hider” side, but there are open-ended tines on the end that may offer some measure of visible flash reduction.  Typically the intent of reducing muzzle climb and/or recoil is to decrease the split times between shots.

Disadvantages
Compensators and brakes tend to be loud.  Some are loud for the shooter, while others are loud for people to either side of the shooter, but most increase the noise level over a dedicated flash suppressor or bare barrel significantly.  This is detrimental on a shooting line, at a public shooting range, or when shooting indoors.

Observations
110222 - Zeroing the gun - 84 rounds: The device definitely increases perceived noise level at the shooter, however muzzle climb is also significantly reduced over the standard A2-type flash hider.  This is certainly aided by the overall weight of the gun, but can be attributed to the design of the compensator as well.
110222 - SFDCC Match - 74 rounds: This particular event did not incorporate any real sustained fire type drills.  It did, however, include a shoot-house and the safety officer commented on the side blast on that stage.  This was an open-top shoot house stage so indoors in a real structure it would be harsher for both the shooter and any team mates, bystanders, or family members.
110301 - Carbine Drills - ~200 rounds:  Will consist largely of 10-round strings of fire at relatively close range (25 yards and in) and should be a good indicator of ability to control the muzzle.

Images





Barrel
Description
Barrel on this sample is the stainless steel 14.5” Noveske Rifleworks Afghan barrel.  Specs include 1:7 rifling twist, 32 oz. weight, 1/2x28 thread pitch for muzzle devices, and a gas port at the mid-length gas system location.  It has also been ceramic coated black on this rifle

Advantages
The primary advantage of this barrel is the accuracy potential.  Noveske Rifleworks is known for making accurate barrels.  Additionally, the polygonal-style rifling that Noveske uses may result in a faster muzzle velocity than a barrel of identical length with traditional rifling.  The added weight of the heavier profile barrel and the stainless steel material also assist in keeping the muzzle down under recoil.

Disadvantages
The obvious disadvantage is weight.  Typically stainless steel barrels also have a rust issue but this is eliminated with the ceramic coating.  Noveske reports the weight as 32 oz. while a 14.5” long A1-profile hammer-forged carbon steel barrel weighs in at 20 oz.  that is a ¾ lb weight difference.

Observations
110222 - Zeroing the gun - 84 rounds:  Ammo fired was XM193, and optic was a 4 MOA red dot scope, so accuracy potential was not observed.  Groups were as would be expected with this ammo, this optic, and more importantly this shooter.

Images




Gas Block
Description
The gas block on this rifle is covered by the free-float rail system and as such is hard to see.  Length appears to be 1” overall and it is of the clamp-on variety.  It is held in place with a single hex-head screw.  It is listed as being constructed of stainless steel and designed by NGA.  It appears to be ceramic coated.

Advantages
Given the design of the free-float rail system a low-profile gas block is required in this application.

Disadvantages
The non-pinned gas block will have a perception problem more than anything else.  Most people who consider themselves in the know believe that all gas blocks should be pinned and not held on by screws or clamping.

Observations
Unsure why NGA didn’t just go with the Noveske part in this application.  That part is typically cross-pinned in place and typically comes with the barrels when purchased from Noveske.

Images





Free-Float Handguard
Description
The hanguard is of a free-floating variety with a Picatinny top rial along it’s full length that is continuous with the flat-top rail of the upper receiver.  The center of the Picatinny rail length is milled out.  The forend rail section is not numbered.  While it gives the appearance of it, it is not a monolithic rail system.  In addition it is made up of two halves, and upper and lower, which are machined as one to give a near seamless appearance.  The bottom section is rail-free but has seven threaded inserts (the first being 0.30” O.C from the muzzle end of the rail system, and every 1.20” O.C. after that) for the attachment of various rail sections via Torx screws, all of which are provided as well as the appropriate wrench.  Rail sections provided are a 4-slot, 7-slot, and 19-slot (or full-length) varieties.

The sides are a mirror image of one another, with the first ~1.2” clear, then a short ~1.75” railed section (again with the center milled out), with the remainder smooth until the barrel nut section which has a ~1.45” long raised portion with a quick-detach sling swivel included; non-rotation-limited.  “NGA X7” is engraved on both of these raised sections at the barrel nut.  These short sections, railed at front and smooth at rear, house the Torx screws used to hold the halves of the free-float handguard system together.   There are cooling slots, 45* above and vertical below, milled into the top and bottom halves of each side.  The entire assembly is machined from aluminum and again ceramic coated, this time in grey.

Advantages
The modular ability to attach rail sections as-needed along the bottom rail is beneficial, especially in an era where more and more shooters move away from vertical foregrips on their rifles.  Having the short rail section allows one to mount the more popular VFGs such as the Tango Down while leaving the rest of the rail free.  This saves weight not only in the basic handguard but also in the covers that most shooters then need to add to the rail sections to protect their hands from the sharp edges of the rail system.

Obviously the free-float rail system aids in accuracy as well due to isolating the barrel itself from any outside forces or objects the handguard may be rested against, as well as any side-pressure when a shooter tightens a shooting sling for marksmanship.

Disadvantages
One advantage that four-rail systems, and their covers, have is insulation from heat generated by the barrel.  For shooters that use gloves this is less of an issue, but for anyone shooting bare-handed an exposed tube, even an exposed aluminum tube, that close to the barrel is going to heat up.  Also, without a four-rail system if the shooter finds themselves needing to attach devices and does not have the additional rail sections, screws, and tool, they are out of luck.

Observations
110222 - SFDCC Match - 74 rounds:  The shape of the bare tube sections is very comfortable.  Narrow in all the right places and really allows the hand to wrap around.  I added an IWC Mount-n-Slot hand stop to the rail by using one of the Torx screws that came with the gun to direct-attach the hand stop and it worked out well for me.  I do find that the forward rail sections are right where I’d like to place my support hand when shooting and wish that they were either not there, or smaller.  I would like the QD sling swivel cups to be rotation-limited.  My sling was binding and twisting on me and I found myself needing to un-twist more than usual.

Images




Upper Receiver
Description
The upper receiver appears to be a standard so-called “milspec” upper with the main exception being a channel cut in the Picatinny rail on top that matches with the rail on the free-float handguard.  It includes the standard features of dust cover, forward assist, and case deflector.  The finish is ceramic coating in a grey color that matches the handguard as well.

Advantages
Since this is possibly the most standard part on the gun, the advantages are minimal.  The slot cut down the center of the Picatinny rail does slightly reduce weight, and also aesthetically matches up with the rail on the handguard system.

Disadvantages
As above with the handguard, the removal of the center portion of the Picatinny rail may lead to interface issues with some mounts, and is certainly not as strong an interface with any mount.

Observations
As with the forend, a full-profile Picatinny rail on the upper receiver would be preferred.  Additionally, going to a non-forward-assist upper would be preferable to me personally, but I understand that this could affect more buyers in a negative way than in a positive and as such have no issue with it remaining.

Bolt/Carrier Group
Description
The bolt and bolt carrier are BCM sourced from Bravo Company USA.  The bolt is therefore Carpenter 158 steel, shot-peened, high pressure tested (HPT) and then magnetic particle inspected (MPI) for cracks and inclusions.  The carrier keys are fully side staked into their mounting screws, and the carrier profile is a full-circle, M-16 (or “auto”) style.  The entire assembly has been ceramic coated black.

Advantages
The Bolt/carrier group (BCG) is the heart of any gun.  While accuracy is determined by the barrel, reliability is a function of the BCG.  Having a quality, properly tested, properly assembled, proper material, bolt and carrier is critical to the continued funciton of the carbine.  the BCM-sourced parts are exactly that.

Disadvantages
None.  Other than the fact that there are several “improved” bolt/carrier groups on the market and some buyers may prefer those alternate parts.  As there is typically no measurable advantage to those parts the choice to go with them would be one of marketing and nothing else.

Observations
None at this time.


Pivot Pin
Description

Advantages

Disadvantages

Observations


Magazine Well
Description

Advantages

Disadvantages

Observations


Magazine Release
Description

Advantages

Disadvantages

Observations


Safety Lever
Description

Advantages

Disadvantages

Observations


Trigger
Description

Advantages

Disadvantages

Observations