Reliability Over Time: The Quiet Strength of a Pinned Gas Block

If you’ve built or customized an AR-15, you’ve probably come across a range of gas block options, from clamp-on to set-screw to pinned. While each has its place, pinning is often misunderstood or dismissed as overkill. However, for those looking to squeeze every ounce of reliability out of their rifle, especially for hard-use or suppressed setups, pinning a gas block might be one of the smartest decisions you can make.

 What a Gas Block Does

Let’s consider what the gas block does for a moment. As soon as the bullet passes the gas port, gases are forced through that port, into the gas block, and then into the gas tube. This redirects gas into the system to cycle the bolt carrier group, extracting the spent casing and chambering the next round.

If the gas port is in any way obstructed, reliable function is compromised, if not entirely prevented. One can imagine the importance of gas block stability given that understanding. If the gas block is allowed to move, the likelihood of obstructing the gas port is extremely high, resulting in malfunctions or a failure to cycle at all.

Common Methods for Securing Gas Blocks

Set Screws
This is probably one of the most common methods used to secure gas blocks to the barrel. It’s what you’ll typically find out of the box with lower-cost brands. Most gas blocks use two set screws that tighten against the barrel. These screws can include knurling to help them bite in.

That said, I wouldn’t put much faith in set screws alone. One thing we know for sure is that recoil is violent on anything that threads. That’s why there are torque standards for parts like barrel nuts, castle nuts, and scope mounts. They must be torqued properly, or they’ll come loose. Castle nuts are even staked because they are critical. Gas block set screws are small and can only take so much torque. Ask around—a stripped set screw is not fun.

Dimplin
Dimpling significantly increases the effectiveness of set screws. What’s great is that you don’t need expensive tools to do it. If you have a vise, jig, hand drill, and the right bit, you can dimple your own barrel. Watching a video or two helps, but it’s very doable.

Dimpling does increase the surface engagement, but it still relies on the set screws staying tight. It doesn’t actually prevent them from loosening over time.

Clamp-On
This method has brought some interesting designs to the market. Clamp-on gas blocks are easy to install and provide decent strength. When you consider the bearing surface along the entire length of the gas block combined with the pressure from cross bolts, it easily outperforms plain set screws.

The ability to apply significant torque to the cross bolts is a plus. Still, this design is vulnerable to thermal expansion, and without a component to prevent rotation, like dimples, it can shift over time.

Pinned
Joshua Hay, our lead armorer at Big Tex Ordnance, puts it best:

“The process of pinning involves drilling a hole through the gas block and a groove into the barrel. Then we insert a pin that anchors both together. This creates a ‘bombproof’ level of security for the gas block.”

When done in addition to dimpling for each set screw, your gas block simply cannot be more secure unless it’s welded on.

 Why Pinning Makes Sense

Any time you’re deciding what to do with a build, it’s important to consider its purpose. If you’re planning to take classes, shoot competitions, or otherwise run the rifle hard, this becomes even more relevant.

This type of shooting exposes the gas block to repeated heat cycles. For set screws, that means slight shifts over time due to heat and recoil. Eventually, that can add up to a critical failure point where the gas block moves enough to compromise the gas port.

Clamp-ons face the same challenge. As the block heats and expands, it’s vulnerable to movement from recoil or bumps. Over time, it may shift far enough to block the gas port, especially on suppressed rifles. Suppressors not only raise the temperature, but they also do it faster.

If your life, or someone else’s, depends on your rifle, why even risk it? For duty rifles, it makes perfect sense.

 Things to Consider Before Pinning

One thing I won’t say is that pinning is the simplest or easiest option. It’s not. While I’ve personally seen Jim Hodge pin a gas block with a hand drill (true story), I wouldn’t recommend that approach. Pinning requires skill, knowledge, and the right tools. It’s not something most folks will learn just for one or two builds.

That said, most gunsmiths should be able to handle it for you.

Keep in mind, pinning is usually permanent. Once you’ve pinned a gas block to a barrel, the chances of another block lining up with that pin are slim. So be sure you’re happy with your gas block choice before committing.

That said, the pin can always be driven out, allowing you to remove the gas block for handguard swaps or maintenance.

 When Is It Worth It?

As mentioned earlier, duty or self-defense rifles are an obvious case. One relatively simple procedure can eliminate a huge potential failure point. When you consider the time and money already invested in protecting yourself, your team, or your family, pinning is a smart move.

Even for rifles that aren’t necessarily for defense, such as when you’re shooting pigs or coyotes with a suppressed setup, it’s worth it. The extra heat and pressure from a suppressor increase the chances of the gas block coming loose. Pinning helps mitigate that risk.

On the other hand, if it’s just a range toy or a rifle for a new shooter—not suppressed and not used hard—you’re probably fine with a clamp-on or a properly installed dimpled set screw setup. There’s no need to overbuild for casual shooting.

 Final Thoughts

Pinning the gas block isn’t for everyone or every build, but it’s one of those upgrades that can turn a good rifle into a rock-solid one. If reliability and long-term durability are high priorities, it’s definitely worth considering.

In a world where tiny failures can cause big problems, small upgrades like this can make all the difference.

Click here to head over to out Armorer Service page to Purchase your Gas Block Pinning

By: Justin Gilbreath