Meet the GunLink Defensive Fighting Rifle SBR

How We Built Out Our Go-To Short Barreled Rifle

GunLink-GDFR_8664A short barreled rifle, while requiring some extra hoops to jump through to obtain (more or less depending on your filing method, now that 41F is in full effect), can be a valuable tool, offering numerous benefits over a full-length rifle as a defensive weapon.

As anyone who has had practical training can tell you, maneuvering through the hallways and rooms of your home to investigate a bump in the night is exponentially easier without those extra inches sticking out past your support hand.  While firing any firearm indoors will likely lead to permanent hearing damage or loss, that risk can be substantially mitigated by using a suppressor.  Putting a can on an AR can push OAL past 40″ on carbines or closer to 50″ on rifles – hardly maneuverable at all – while mounting one to an SBR might make it only as long as an unsuppressed rifle by itself.  While  those benefits really shine when clearing rooms and maneuvering through halls and doorways, the likelihood of having to use your AR to defend your home is relatively remote; however, there are also practical benefits.  An SBR is lighter, shorter, and much easier to store and transport, both in terms of the space it takes up as well as the options for covert carry cases.

I have always been interested in NFA firearms and one of the things that you frequently hear from owners of such firearms is that one of the big joys of ownership is the ability to share them with others.  Before jumping into the world of NFA, I always figured that this was nonsense and all of the fun came from the fact that one owned a machinegun, SBR, SBS, silencer or other fun, interesting weapon.  After Team GunLink started “stamp collecting,” we realized that it is truly a pleasure to see the smiles on people’s faces when they shoot with them.


One of the NFA firearms that we most frequently take to the range and classes and post about on social media is an AR-type modern sporting rifle based SBR.  Here is how we configured our go-to SBR – the GunLink Defensive (Fighting) Rifle – it’s GDFR.

RubberCity_5281The core of the GDFR – what places it in Title II territory – is the PSA 11.5″ barreled upper.  Significantly less length than a standard 16.5″ carbine with more dwell time and muzzle velocity than a 10.5″ or shorter barrel – the best of both worlds.  Inside this is the Rubber City Armory Black Nitride bolt carrier group (BCG) that we picked up during our visit to the RCA shop.  We experimented with the RCA low-mass BCG with adjustable gas key.  However, pending the resolution of an issue with the adjustable key, the low-mass setup now spends its time on the bench or in another rifle.

The upper is outfitted with a standard FSB to use with the Troy Folding Battle Sight.  We switched to this BUIS from the ARMS #40 because it would fit under a QD magnifier.  For the muzzle device, we swapped out the standard A2 birdcage for the suppressor-friendly version of the YHM Phantom comp to accommodate the Phantom LT .30 can.

GunLink-GDFR_8659We swapped out the standard carbine handguards for a drop-in quad-rail for a couple of reasons.  This allowed for adding a vertical forward grip (VFG) for easier and more comfortable comfort and maneuverability, as well as providing a storage place for tax stamps.  Also, since the PSA upper has a shaved bayonet lug, it allowed us to switch from the Elzetta ZFH-1500 mount for the ZRX mount that they released a couple of years ago for the white light.  Removing the ZFH mount also freed-up the FSB for the side-sling mount.

In that sling mount, we put a Vickers Combat Applications Sling by Blue Force Gear. Probably one of, if not the, best AR slings out there.  Two point design, durable, versatile, and quickly adjustable.

GunLink-GDFR_8655The GDFR originally sported a red dot on a high-cantilever mount that put it forward enough to allow for a 3x magnifier behind it.  Since turning this rifle into an SBR, we see less need for the magnifier, so the cant mount isn’t really necessary anymore.  This is a moot point, however, since after visiting Vortex at SHOT Show, we submitted a pre-order for both a SPARC AR red dot sight and a SPITFIRE AR prism sight.  After handling them and looking through them at SHOT, we think this will be a nice upgrade.  The SPITFIRE was initially my preference to live on the GDFR but, with the longer eye relief necessitated by the folding rear sight occupying the rearward portion of the rail, the SPITFIRE didn’t look so good, so the SPARC AR won out here.

GunLink-GDFR_8647When cased, stored in the safe, or at the range (basically, any time when not doing courses or practice that requires transitions), we keep the Vickers Sling managed with Sling Bandits.  Neat little gadgets that take up the slack and keep the sling tight against the side of the rifle while allowing it to be used just as quickly (or more quickly, if you consider that, without them, the sling could be tangled or caught on other objects).

The pistol grip has finally ended up being a Magpul K2+.  This rifle has gone through a few iterations with the grip.  It started out with the original Ergo Grip, and then a regular Magpul K2 grip for a more vertical grip angle, and, finally, the K2+ for NFA paperwork storage once that became a necessity.  With this configuration, it is easy to reach the trigger, in this case, a Timney 3 lb drop-in unit.  The Timney has a nice, crisp break, short reset, no creep, and, after replacing the standard hammer spring with the heavier version, has no problem cracking the hard primers in some of our cheap range ammo.  The GDFR gets fed a steady diet of 5.56 and .223 ammo by means of the famous Brownells magazine with tan-followers.GunLink-GDFR_8660

The 5.56 round already starts out pretty loud, and it only gets louder out of the 11.5″ barrel with the YHM flash hider on it.  This configuration is aurally offensive enough at outdoor ranges and much worse in indoor ranges or hallways.  While centerfire rifle rounds will still be loud with a suppressor, a can will contain the majority of the eardrum-shredding concussive blast.  To fill that role, we chose the Yankee Hill Machine Phantom LT can, which YHM claims will bring .308 rounds down to hearing safe levels and which, thanks to the extra volume, performs even better on 5.56 according to the Silencer Shop tests.  The only downside of having the silencer on the GDFR is that it adds almost 8″ of length and over a pound of extra weight hanging off of the end which, while still more than manageable, significantly increases the overall weight of the otherwise lightweight SBR.  This is a simple fix however – if we would rather have shorter and louder instead of longer and quieter, the ratcheting QD mount allows the Phantom .30 LT to be easily mounted or removed with a just a few twists.  And since we have outfitted several rifles with the mounts, moving the can back and forth is quick and easy.

I think that the team is now satisfied with the GDFR configuration and, unless some great new whiz-bang add-on comes along or one of the current components gives us a good reason to remove or replace it, this configuration is how it will stay.  The rifle doesn’t take up much space in the safe, it is easy to transport to and from the range, and if the SHTF and it starts goin’ down for real, the above features will surely come in handy.

Let us know how you set up your MSR-style SBR in the comments section below or on the GunLink forums.


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