The AR-15 platform has shown that it can be trusted if made to the proper specifications and with quality parts. While it is a reliable platform, this does not mean that the thought of maintaining it should go out the window. Part of maintaining the AR-15 is replacing worn springs. Below are some of the springs inside the AR-15 that may slip your mind, and some tips on how to replace them.
Different Ways to Conduct Preventive Maintenance
There are two ways to look at conducting preventative maintenance. One is by doing annual inspections and checks. The other is by round count. The military, Army specifically, does annual inspections and gauging when it comes to the M4 platform. Every year armorers/small arms repairers visit each unit and inspect their weapons for worn or damaged parts.
On the consumer/civilian side, many conduct preventative maintenance according to round count due to not firing their firearm on such a routine basis as the military does. Long days at the range are much more sporadic on the civilian side, thus jotting down round counts and inspecting parts according to those numbers is much easier to track.
Remember, the rule of thumb when it comes to maintaining anything is that you want to replace things before they cause malfunction. You are maintaining the gun.
Replacing the Extractor Spring Assembly
The extractor spring is best replaced as an entire assembly. Depending on your firearm there will be a spring, a buffer inside that spring, and maybe an O ring around that assembly — again, that depends on the firearm. Replace that entire assembly when it is time to replace the extractor spring.
There are two parts of the extractor that are essential for proper extraction. One is the sharp lip on the end of the extractor that grabs the case to pull it out of the chamber. The second is the spring that pushes that extractor out far enough to wrap around the case. Many times if the extractor spring assembly is worn down there will be a failure to extract.
You may notice the malfunctions before you remember to replace the spring. However, 3,000 rounds are a general rule of thumb when it comes to this part. If you want to inspect the part and not worry about the round count, if you notice that the spring is now bent or very compressed, or if you take a punch to the extractor and notice little spring tension, it is time to replace the assembly.
To reach the extractor spring the extractor must be removed. Apply pressure to where the spring is under the extractor, then using a small punch push the extractor pin out.
The extractor has a small round housing for the extractor spring which also has a lip on it. Using small pliers and without smushing the spring, twist the spring into the housing, starting with the end of the spring, just like you would do when trying to twist any coil onto something. After it is started you can then apply a small amount of pressure to the top of the spring until you hear it click in. Ensure that it is fully seated by giving a very gentle tug. Don’t forget to place your O-ring around the spring if your specific extractor needs it.
Install the extractor the same way that it was removed.
Replacing Disconnect Springs
This part will depend on the type of trigger that you have in your AR. If it is a duty-type trigger such as a M4/M16 type trigger there will be a small spring located under the disconnector which allows the disconnect to either lock or unlock from the hammer sear.
If you are running an aftermarket trigger such as a higher-end single or two-stage trigger, the warranty will most likely say not to replace or attempt to repair any parts within that trigger, thus, this section will not apply to you.
With older M16 platform-type guns, many are seeing malfunctions in the gun due to worn disconnect springs. The most prevalent malfunction is firearms firing two rounds back to back. This is also called “hammer follow” in which the hammer doesn’t lock back to the disconnect after a round is fired and the gun cycles.
Disconnect springs can be replaced every 3-5,000 rounds. However, if wear is noticed on the disconnect or sear itself, go ahead and replace the parts and springs showing wear. Obviously, if malfunctions occur you will want to replace the springs then. Start small, replace the springs first, then move to other parts.
Disconnect springs are captured by a housing in the trigger with a ridge on it. The springs are also cone-shaped, meaning the bottom of the spring is larger than the top. Place the larger part of the spring (the bottom) into the house by twisting to the right as the spring will now catch the small ridge on the housing. You don’t want to smush the spring into the housing, as this will damage the spring.
Replacing the Selector Spring
The selector spring is one of the easier parts to inspect and replace, but often gets forgotten about. This spring is located under the pistol grip and is used to push a selector detent into the selector allowing movement and locking when moving the selector from safe to semi. Thus, selector spring.
A broken or bent selector spring can cause not only a difficult-to-move selector but total immobility of the selector. As you know, this is really dangerous if in a defensive scenario. No ability to move the selector means no ability to fire the gun. This has been seen before. More often though, the selector is either just very badly rusted or bent.
This check is done annually in the Army. It is such an easy check I would recommend doing it if you start to feel the selector has a sticky feeling or when you are field stripping your firearm to clean it.
To reach the selector spring you must first remove the pistol grip. This is done with either a long Allen wrench or screwdriver depending on your pistol grip. It is really easy to bend the selector spring as you are both removing and installing the pistol grip, so ensure that the grip comes straight off and is put straight back on. I like to push down on the pistol grip until the grip screw is entirely loosened and able to be removed. Once the grip is off you will see the selector spring and under that, the selector detent. The lower receiver may need a couple of taps to remove the detent from it. Be careful not to lose it.
If the selector spring is bent, stretched, or really rusted, go ahead and replace it. Don’t be afraid to add some lube or grease such as LSA-T on the selector spring and detent. It helps with the movement of the selector and protection of the spring.
To reinstall, put the pointy end of the detent down first into the receiver. Then place the spring back into the pistol grip (after cleaning the inside of the spring hole of the grip as well) and press straight down into the selector spring hole into the receiver. Do not bend the selector spring that you just replaced. Keep pressing down until the grip screw is entirely tightened down.
Replacing the Ejector Spring
The ejector spring is located under the ejector on the bolt and is there to provide enough tension to push the casing out of the receiver as the gun cycles. A damaged ejector spring can cause stovepipes and failures to eject.
While ejector springs are fully enclosed inside the bolt, things can still happen to it. A worn-down ejector spring can cause failures to eject which often are misdiagnosed as other malfunctions. There have been instances of these ejector springs even being broken in half and only found after the gun experienced malfunctions.
There are two main ways to know when it may be time to replace the ejector spring. One, the ejector should have a good amount of tension. If it doesn’t, the spring is probably worn down. You shouldn’t be able to easily push down on it with your finger and you should feel tension and resistance when pushing on it with a punch. Two, if the ejector is sitting lower than highest wall of the bolt, there is probably a problem with the spring as well.
If you are replacing the entire bolt assembly, the ejector and ejector spring should also be replaced.
The removal and installation of the ejector is a little bit of a harder repair due to having to apply pressure to the ejector to line up the pin. Below is a video on how you can do this without any special tools except a small punch, brass hammer, and bench block.
If you are still having a hard time, there are special ejector removal tools on the market.