Did you know that all AR-15 and AR-10 bolt carriers tilt down at the rear end as the action cycles? This phenomenon called “carrier tilt” became widely known when piston driven ARs became popular because in some cases it was severe enough to cause obvious damage to the gun in short order. On the piston guns, the gas piston strikes the solid carrier key on top of the bolt carrier to drive it to the rear. This strike at the top of the carrier causes the lower, rear of the carrier to tilt downward as it starts to move which makes it contact the lower portion of the buffer tube (receiver extension). On most standard bolt carriers, the rear of the carrier is completely unsupported and there is enough play in the tolerances between the carrier guide rails at the front and the upper receiver to allow this movement. So a lot of piston guns were getting noticeable wear in the buffer tube or at the front edge of the buffer tube after just a few hundred rounds and customers didn’t like this. To fix the problem, piston gun manufacturers enlarged the profile of the rear end of the carriers and beveled them or machined “skids” into them so they couldn’t tilt as far and if they did impact the buffer tube, the wear wouldn’t be as significant. This is a partial solution for the piston guns, but some tilt may still happen depending on the tolerances and there is a bit of movement before the carrier gets inside the buffer tube where the skids can help.
What most AR shooters don’t realize is that the Direct Impingement Guns or “Gas Guns” also suffer from some carrier tilt. It usually isn’t as much so it may not result in any buffer tube wear or other obvious visual signs. But the gas still hits the carrier at the top, just as it does on a piston gun causing the rear to tilt. It’s impact just isn’t as abrupt as a piston is, so the tilt isn’t normally as severe. But there is still the same amount of play in the carrier to receiver fit to allow for tilt on a gas gun and it still can have negative consequences even if it isn’t damaging your buffer tube. When the carrier tilts as it starts moving to the rear and unlocking the bolt, it is putting extra stress on the bolt which is still locked into the barrel trying to turn and pull through the locking lugs. This stress can eventually cause the bolt to crack and break, normally at the locking lugs or at the cam pin hole, which are two of the thinnest and most stressed points on the bolt. So that’s a serious problem right? If your bolt breaks, your weapon is down hard until it can be replaced.
So how do we solve this problem? The piston gun manufacturers modified the design of the rear end of the carrier as mentioned above. That’s a good thing. Many shooters carry a spare bolt in their pistol grip which is a prudent idea in case one does break. Some of the top tier companies started making their bolts out of tougher steels and doing more quality control on the bolts which raised the price a bit, but is a good thing for the gun owner and does reduce breakage. But in my mind, a real solution needs to get rid of the carrier tilt in the first place and remove these stresses from the operating system altogether. That’s where the anti-tilt buffer comes in. An anti-tilt buffer has a protrusion at its front end that extends into the hole in the rear of the bolt carrier. It supports the bolt carrier through it’s entire cycle not allowing it to tilt more than a few thousandths of an inch. So the buffer tube doesn’t get any wear, the bolt doesn’t endure any stresses from the carrier tilt and the entire system cycles more smoothly because there is less friction. All in all this is a great solution. As you should know, there’s always a trade off somewhere for these advantages, so what’s the down side of an anti-tilt buffer? Since the buffer is holding onto the rear of the carrier, you can’t just pull the rear takedown pin and shotgun open the action. You have to pull both the rear and the front takedown pins and pull the upper receiver completely off of the lower receiver to open the action. Not too bad right? Some folks don’t like this because they are so used to opening up the action that way, but it’s a pretty small trade off for a smoother running, longer lasting operating system if you ask me. Besides, now days you can find all sorts of easy pull take down pins to make pulling them both a breeze. So if you want the smoothest running, longest lasting operating system you can have take a close look at some anti-tilt buffers. The CTS Aktive buffers are some of the best.
Without a doubt, the AKTIVE Buffers by CTS Engineering would be one of my first picks for any AR-15 or AR-10 rifle with a fixed stock. They have a solid stainless steel buffer body with an overall weight that has been finely tuned for excellent performance in those specific platforms. But even more importantly, they have a shock absorbing piston on the front end and a far superior bumper on the rear end for a dual stage buffering action. This action really does make a noticeable difference in the smoothness and recoil of the weapon. I’ve seen a lot of buffers over the years and this is probably the best bang for the buck of any buffer on the market. The AKTIVE buffers are made in both a standard and an anti-tilt version in so you can have every feature you could want on a buffer. They run as smoothly and quietly as any buffer system on the market, so if you are thinking about using a suppressor, they are a great choice for that too. Heavy loads or light loads? No problem. Match them up with a tuned, ground and polished JP buffer spring for the quietest operation possible. You will be very pleased, I assure you that. If you have a fixed stock AR type rifle, this is one of the best upgrades you can buy for it.
CTS Engineering has developed an innovative new line of buffers for AR-15 and AR-10 series rifles, carbines and pistols. Their buffers, called AKTIVE buffers, are made with a stainless steel buffer body and a 2-stage buffering action to reduce recoil and muzzle movement and smooth out the operation of the action. The aktive buffers have a hard polymer piston head that compresses an elastomer shock absorber inside the buffer as the bolt carrier and buffer impact the rear of the buffer tube.
It also has an improved rear bumper that has superior shock absorption than a conventional rear bumper.
The buffering actions on the front and rear of the buffer work in tandem to soften the blow and reduce shock and recoil that comes from the bolt carrier. The piston head also works to dampen the forward impact of the bolt carrier going into battery as well. Since it is acting as “sprung weight” instead of “dead weight”, it doesn’t feel like as much of a slam forward as with an equal weight conventional or solid heavy buffer.
When shooting with an AKTIVE buffer compared side by side to a conventional buffer, it feels like it does soften the recoil to the shoulder enough to notice and the sights don’t move off target as far. It feels softer recoiling than conventional buffers, H2 buffers, tungsten powder buffers and solid heavy buffers. Additionally, the cycling of the action as a whole just feels smoother. A further benefit of these buffers is that they dramatically reduce spring noise and vibration for a quieter running system which most AR shooters would agree is a nice touch. They work well with factory buffer springs or upgraded aftermarket springs.
Aktive buffers come in a wide variety of models including standard carbine sized 3.25″ buffers, AR-15 rifle length buffers, AR-10 rifle length buffers and even Vltor A5 compatible buffers. AR-10 carbines that use a 3.25″ buffer (such as Sig, LWRC and Armalite) can use the AR-15 carbine Aktive buffer as long as it is paired with an AR-10 carbine buffer spring. Additionally, they are available in standard and anti-tilt configurations for every model. The anti-tilt versions have a protrusion at the front of the buffer that extends about a tenth of an inch into the rear of the bolt carrier to support it and keep it from tilting during cycling. This is especially helpful with piston guns, but all ARs have some degree of carrier tilt and this helps to smooth it out. The polymer piston head that is in contact with the buffer tube is quiet and prevents wear on the buffer tube. Having the rear of the bolt carrier supported makes a lot of sense not only to prevent buffer tube wear, but to put less stress on the bolt, cam pin, gas tube and upper receiver that would all be effected by carrier tilt. The anti-tilt versions cost the same as the standard versions, but does require that you pull both the rear and front take down pins in order to open the action. Some folks don’t like not being able to break open their action like a shotgun, but pulling two pins instead of one seems like a small price to pay for better operation and less wear. But whichever suits your fancy, there’s a model for you. Once you grasp all the features and benefits these buffers have to offer, the $65-70 price range seems like a pretty fair deal. They are available for purchase at www.nokick.com.