To support other companies’ efforts in developing products, Plumb Precision Products LLC conducts in-depth testing. One weapon system that we have extensive expertise with is the FN SCAR ®. From its inception as USSOCOM Program, through its release as a commercial market rifle, and to its current variations, Plumb Precision Products has led the way on aftermarket product development.
This particular SCAR® was built in 2013. It was often a test bed for multiple development efforts of several other companies. Plumb Precision Products testing regimens are directly derived from DoD testing methods. Both DoD environmental testing and shooting tables are applied.
While most of these tests are shooting based, some are not. We conduct Accelerometer and High-Speed video analysis of how products deal with the unique energy of the SCAR® platform. Lasers, Optics, Suppressors, Triggers, Barrels, and many other products have seen our extensive testing.
But the one item that is often overlooked in this type of testing is the durability of the weapon itself.
After years of use, 20,000 rounds of various 7.62x51 cartridges, a multitude of suppressors, in all kinds of conditions, here is what we found.
Trigger Module
The trigger module was quickly replaced with a AZ31 magnesium blend alloy trigger module. It still runs the OEM trigger assembly as I wanted to verify when the triggers would start to have issues. The old OEM triggers were much more a machine gun trigger than rifle trigger. The older variants were also more prone to having their Sear wear out. The first trigger hammer was replaced at about 5000 rounds for this very reason. The second hammer is from a later and much better batch and has held up for 15000 rounds. It also known the Geissele and Shooting sight triggers will also stand up to this level of abuse.
The selector drum was OEM until replaced by an AXTS 45/90 type. Unfortunately, they do not stand up to heavy abuse and the retaining pins have a tendency to shear off. It was quickly replaced by a Handl Defense variant. The Handl Defense Selector switches lasted much longer, but alas the screws are too small and ended up shearing off as well. The OEM drum and Magpul selectors are my recommendation.
The internal components are all Handl Defense Maritime Kit parts. As expected, the turned parts from bar stock have held up without issue.
The trigger module itself is made from a Magnesium blend and then hydro dipped. The trigger module is a looser fit than when originally fitted. It still adds some compressive strength and torsional rigidity to the platform with minimal weight penalty. Other than external abuse, it has held up.
Upper receiver
The upper receiver is 100% original. None of the parts were ever replaced. Not one screw, backing plate, or another component ever failed or wore excessively. Only the receiver back plate would eventually work its screws loose and would need to be retightened. I checked to see if any of the holes ever elongated, none was noted.
The internal rails do show some signs of wear. The internal surfaces are worn consistent with heavy use. The bolt cam guide rod has signs of only surface wear. When disassembled (back plate removed) and put on a flat surface, there is no sign of receiver torque, which has been noted on some SCAR® rifles over driven by suppression and ammunition. The upper receiver looks worn, but it is solid.
Bolt Carrier Group
The bolt carrier group is always one of the first items I check when inspecting a SCAR® rifle. The bolt cam pathway is a place of notorious failures from excess wear on the system. There are no cracks or bulges in the metal. No burrs are formed on inside of the BCG. The bolt moves smoothly in its track. There is a moderate amount of external wear on the BCG itself.
There are tabs on the front and rear of the BCG. These are on top and help guide it along its internal track. These are worn through the external coating. This wear pattern is found elsewhere on the BCG. The top and near the ejection port are also worn in the same manner. This is consistent with this level of use. The rear of the BCG is worn shiny. This is the most worn I have seen a commercial market gun’s BCG.
The bolt shows no excess wear or deformities. The bolt face does show a moderate amount of wear around the firing pin hole. This is consistent with the level of use. I would consider this bolt near the end of its serviceable life.
Of note this SCAR is on its 4th charging handle. It has broken a G&GG, OEM, and KDG charging handle. It is also on its second firing pin, and recoil spring.
None of these findings effects the function of the BCG.
Stock Assembly
The stock has always been the OEM assembly except for about 1 year when a Handl Defense Alloy Stock Hinge replaced the OEM polymer Hinge. For an un-suppressed rifle this an improvement over the OEM hinge. The brake point of the hinge goes from about 55lbs to over 90lbs. The issue is that alloy hinge causes accelerated wear on the back plate screws with higher pressure ammunition and suppression. The effects of this were profoundly enough to cause the product to be discontinued because USSOCOM and Commercial Market use was suppressor dependent.
This is the second OEM hinge part that has been used. The first was excessively worn to cause chipping and a small split to appear at about 12,000 rounds. This is a replaceable part. To date there has not been a stock assembly that has stood up to the same level of use as the OEM assembly.
Barrel Assembly
This barrel was coated for aesthetic purposes around the 3000-round mark. It now permanently discolored from the heating cycles of testing. Excess gas and carbon expelled around the gas block and gas selector have turned the upper barrel portion and front sight assembly permanently black. On inspection the barrel’s lands and grooves are still pronounced. The projectile dispersion at 100 yards is still decent and a marginally acceptable 1.75-2.0 MOA with 147 grain M80 ball ammunition. There is a drop in overall accuracy and dispersion. I would consider this barrel to be at the end of its life. It’s functional but finished.
The SCAR® has shown itself to be a durable weapon system. It keeps a functional level of function and accuracy, with the right ammunition, well past what almost all commercial market platforms will endure. What is important to note is that Select Fire conversions, higher pressure ammunition like 175grain 118LR, and poorly matched suppressors will radically accelerate wear. I have seen customers guns with elongated screw holes, damaged backplates, worn bolt cam rails, damaged BCG’s, and warped upper receivers. I consider that all from poor care, ammunition choices, and suppressor selection.
The SCAR has shown that it is durable far beyond what one would expect for commercial market use. It does require maintenance and inspection. Occasionally a few parts will need to be replaced. But as a long-term firearm it is far more durable than even I expected.