AR Basics: The Futile Forward Assist


If you need the forward assist to close your AR’s bolt, something is wrong with the gun.

What is the forward assist, and what is its purpose?

    • The forward assist, or bolt-closure device, is a way to manually close an AR's bolt.
    • Eugene Stoner did not originally design the M16 with an external forward assist.
    • The U.S. Army demanded an external forward assist on the rifle.
    • If the bolt won’t close under its own power, the rifle's telling you there’s a problem.
    • You are better off unloading and reloading to solve the problem.
    • A press check is used to ensure a round is in the chamber.

The M16/AR-15 has done a lot of evolving since the original concept. Most of the improvements have been a good thing — changes that created a more reliable platform. However, some of the changes, especially between the original configuration of the AR-15 and “military improvements” that would come later, are questionable.

The forward assist, or bolt-closure device, is located on the right rear of the upper receiver. It uses a ratchet action to force the bolt forward into battery. The upper receiver (pictured top) is an early model without an external forward assist.
The forward assist, or bolt-closure device, is located on the right rear of the upper receiver. It uses a ratchet action to force the bolt forward into battery. The upper receiver (pictured top) is an early model without an external forward assist.

This is especially true of the external forward assist. A sure way to spark up a debate among true AR guys is to bring up the topic of forward assists: A lot of new AR owners don’t have any idea what the forward assist is — or what it was originally designed to do.

So, what is the forward assist? What does it do? And, what do you do if your AR doesn’t have one?

The Long-Lost ‘Button’

The forward assist, or bolt-closure device, is a way to manually close the bolt of the rifle. For example, you might have a round of ammunition that’s dirty or slightly deformed and doesn’t want to chamber.

Regardless of the cause, when the normal spring pressure on the bolt group doesn’t successfully chamber a round, locking the bolt into position, the forward assist is used to manually force the bolt forward, seating it in place.

The M1, M14 and .30 Carbine all have “external” forward assists on the charging handle. The same is true of the AK, SKS and other Soviet designs. The exposed charging handle on these rifles allows you to manually force the bolt forward. As originally designed, and on purpose, the M16/AR-15 did not have an external forward assist.

Stoner didn’t want the M16 to have an external forward assist because he saw no need for it. According to The Black Rifle — the ultimate source on the M16 platform — Stoner stated that after many types of testing programs, “I never saw an instance where it would have done any good … under sand and mud and every type of firing conditions in the world.” He also stated, “… when you get a cartridge that won’t seat in a rifle and you deliberately drive it in (to the chamber), usually you are buying yourself more trouble.”

Plus, Stoner wanted as few parts as necessary in order to make the overall design as lightweight as possible. As Colt went after government contracts, the testing continued with various military branches. The Air Force was happy with a rifle lacking a forward assist, and in fact their first order for M16s specified them to not have one. The Army had different thoughts: they demanded an external forward assist be added to the M16.

To seat the bolt without a forward assist, use a finger — or thumb for left-handed shooters — of the support hand to lock it in. If the bolt still won’t seat with finger pressure, the rifle is telling you there is a problem and you should unload to inspect.
To seat the bolt without a forward assist, use a finger — or thumb for left-handed shooters — of the support hand to lock it in. If the bolt still won’t seat with finger pressure, the rifle is telling you there is a problem and you should unload to inspect.

Even though the Army mandated a forward assist for the M16, they admitted that it was more of a psychological matter than a mechanical one. They stated that, “The frequency or infrequency of the type of malfunction correctable by a manual bolt closure capability is immaterial. The knowledge among troops that such as malfunction is merely possible would lower confidence in a weapon lacking (such) a device.”

Since the M16/AR-15’s charging handle rides inside the upper receiver, it was more difficult to come up with a way to modify the existing design in order to add an external forward assist. Colt experimented and tested a few different ideas, and after considering several possibilities decided to add the forward assist onto the right, rear side of the upper receiver.

The modification that won out consists of a plunger, a pawl, two springs and two pins to hold everything together. A “tube” was added to the outside of the upper receiver to house everything. The plunger rides inside the tube on the receiver, and when pressed forward the pawl indexes with corresponding teeth on the bolt carrier to force the bolt group forward. When pressure is released on the plunger, a spring forces it back to the rear and the pawl retracts with it.

Life Without Forward Assist

So, what do you do if the bolt won’t seat on its own, and you believe as Stoner did that it’s a bad idea to force a round into the chamber?

Let’s say you’re loading the rifle, manually cycling the charging handle in order to chamber a round. You release the charging handle, ensuring your hand comes completely off the handle, letting the buffer spring force the bolt forward with full spring pressure. For some reason the buffer spring doesn’t have enough force to chamber the round — the bolt is out of battery, which means the gun won’t go bang.

This could be due to a faulty round that has been damaged, distorting its shape. It’s also possible the chamber is really dirty, with carbon and powder residue built up, preventing the round from chambering. Maybe you put too many rounds in the magazine, and the resulting spring pressure is too tight to allow the bolt to strip a round out of the mag smoothly. And the most dangerous condition is when you have a throat or barrel obstruction — for example a bullet that stripped from the case during unloading. If you try to force a round behind this and into chamber, eventually it will go, and now you’ve got an explosion coming up when you attempt to fire the next round.

If the bolt won’t close under its own power, that’s the rifle telling you there’s a problem. Instead of using the forward assist to jam the round in — forcing the round into the chamber will probably create a stoppage or malfunction — you’re better off unloading and starting the process over. Unload, and load. If it turns out the chamber is fouled, and attempting to load again isn’t successful, then you’ll need to give everything a good cleaning.


After loading, we teach students to perform a press or chamber check to confirm that they did indeed end up with a round in the chamber. Just because you went through all the actions to load doesn’t guarantee you got one chambered. Confirming you are truly loaded is cheap insurance.

To perform a press check, pull the charging handle back slightly, exposing the round – which is hooked onto the extractor. You visually or physically confirm there is a round chambered. Once confirmed, you release the charging handle, letting it snap forward with full spring pressure on the bolt. If for some reason the bolt doesn’t seat, you put a finger or thumb of the support hand into the concave cutout area of the bolt carrier — which is exposed in the ejection port — and press the carrier forward. When finger pressure doesn’t seat the bolt, you’ll need to unload and load. Again, don’t try to force it by hammering on the forward assist.

If your AR doesn’t have an external forward assist, don’t sweat it. You don’t need one. “But,” you say, “my AR has an external forward assist.” My advice is ignore it — treating it like a vestigial organ — and manipulate the AR the way Stoner designed it.

Editor's Note: This article originally appeared in the Winter 2017 issue of Gun Digest the Magazine.

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  1. I disagree. The military still trains to use the FA and it can be useful. In my opinion it is close to necessary and I wouldn’t want an AR without one unless it was a reciprocating side charged AR. Sometimes the bolt doesn’t quite close all the way especially when in dirty conditions or high round counts without cleaning. Before you say keep your rifle clean, go get in an extended firefight and stop to pop the rear pin, pull your BCG out to clean your rifle all while bullets are zipping past your head, and see where that gets you! In a situation like that the FA is a great feature. It can also be tapped as a reassurance that the bolt is closed all the way. It sucks when you pull the trigger and only get a click because the bolt wasn’t fully locked in the chamber. Now as far as it being a fix all or able to fix a jam that’s obviously false but it is most certainly useful and anyone that has been in an extended firefight in poor conditions such as desert would agree they prefer a FA over no FA. When the bolt doesn’t quite close would you rather tap a button and continue or re-rack the non-reciprocating charging handle losing a round and having the possibility of the same damn thing happening again?

  2. You really need to come up a little to include opinions of those that required its use in firefights. While the author may be a “lifelong student of personal combat,” NOWHERE does it mention military service or any form of ACTUAL combat.

    The assist, while nearly useless in the civilian world, was place there for the very reasons the gun is “telling” you there’s a problem, likely a fouled chamber. In the midst of a firefight one doesn’t have the time to break down their M-16 and give it a proper cleaning. They need it to go bang, fast, and a LOT.

    I will say that my assist has come in handy, mainly on new guns that are not properly broken in yet, especially after the above-mentioned loaded chamber check. There are also times you need to be QUIET, and letting the carrier fly home might give away one’s position or tactical advantage, especially in situations of home defense, police, or structure clearing by a military force. When I do this I habitually give the FA a couple of pumps to ensure the bolt is fully into battery and I will get a “bang” when I need it. It’s almost never necessary, but it is reassuring.

    So yes, in most shooters lives the FA is a superfluous piece, but to say it is useless and serves no purpose the general AR user is overstating it. Also, it adds almost no weight and doesn’t hurt anything by being there, having zero effect or normal function. Ultimately, the only absolute is there are no absolutes.

  3. Another way to verify a round has been chambered is to look at the round at the top of the magazine before insertion and note whether the round is on the right or the left. . After releasing the bolt , remove the magazine and verify that the top round is on the other side. This method does not require manipulation of the bolt and it can be accomplished in the dark by using your finger to ascertain the position of the top cartridge.


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