Doctor, it hurts when I do that!

One of the oldest jokes out there, right? This guy goes in to the doctor’s office, jams his finger into his eye and says “Doctor, Doctor, it hurts when I do that!” So the doc looks at him and says “stop doing that.” Seems like a simple fix, doesn’t it? The problem is that people have a tough time applying that same logic to their personally owned firearms, especially after they’ve added upgrades to those guns.

Take threaded barrels as an example. Most people add a threaded barrel to their guns for one of two reasons: to either add a suppressor or a compensator. Today we’ll take a look at the common problems associated with adding a compensator to your gun, and how to ameliorate them.

Problem 1: Failure to eject or weak ejection
This is by far the most common issue when you add a compensator to a custom build. The reason for this is science: namely gas pressure. Recoil operated firearms need X amount of pressure to unlock the gun and fully compress the recoil spring to allow for proper function. Without a comp, the pressure is distributed evenly in all directions, allowing the gun to cycle the way it was designed. With a compensator, some of the pressure is vented straight up, some out the sides (depending on the design) which can compromise function. This usually happens when you use ammo that’s very low pressure, like a lot of currently manufacturered factory 9mm.

Two simple things can work to fix this: 1) don’t use cheap ammo. While that sounds harsh, ammo that’s loaded to a price point is far more likely to cut corners on powder charges, which means lower pressure ammo, which means a lower likelihood of the gun working correctly. Use quality ammo from a reputable manufacturer that you know is loaded to SAAMI specs and you’ll probably be fine. Or use stuff that you know to be loaded a little hotter if you want to maximize the compensation effect from your build.

Secondly, you can use a lighter weight recoil spring. This is a popular fix, especially with competition shooters, as it will also help the gun cycle flatter during rapid firing. While using a lighter recoil spring can fix the problem caused by lightly loaded ammo, it can lead to Problem 2 that we look at below.

Problem 2: Failure to feed
Here we have the second problem associated with compensators, which is a failure to feed. The reason that a comp can cause FTF stoppages is that it changes the cyclic rate of the slide, again due to it changing the gas pressure. Where this issue rears its head most frequently is with older magazines. Because the slide is moving at a different velocity, the spring in the magazine may not be able to move the round into position at the appropriate time. The simple fix for this is when your magazines start wearing out, toss them in the garbage. Life is too short to deal with junked magazines, and new replacements are cheap and readily available in our store. Seriously, if you’re still running ancient mags, go buy some new magazines. Or, If you are more frugal in nature (save the planet!)…inspect the inside and outside of the magazine bodies for damage, and then go buy some new springs and followers!

Problem 3: Nothing’s working, everything is terrible, and I hate this stupid **** gun
We’ve all been there. You get your build assembled, you’re excited to get it out to the range, and then…it just refuses to function. It’s not feeding right, it’s not extracting right, the trigger feels gross, and your front sight just flew into low earth orbit because you didn’t loctite it properly.

Here’s the simple fix for that: do your builds in iterative steps, testing as you go. If it’s your first time building a gun to your specs, test every new part. If you install a new trigger, test it before you put any additional parts in there. When you put the threaded barrel and compensator in, test it before you add any new parts. Don’t just assemble a parts list based on something you read on the internet, test everything yourself so you know it works. Especially when dealing with threaded barrels and compensators.

Hopefully you’ve found this helpful and your next range session will go more smoothly!


  1. Doc! My cigarette just flew into low earth orbit because I didn’t loctite it properly… Then read this article and nearly died laughing. How do I fix that?

    1. Nikolay: You didn’t loctite that cig to what, your fingers, or your lip? LOL! My suggested fix, smoke less so you have that $ available to shoot more – the lead exposure from handling live ammo (and just-fired brass) and the GSR in the ambient air at the range is probably less harmful than what smoking does to your insides anyway. Just remember to wash your hands after shooting before eating.

  2. I’m looking to order a custom LWD G22 slide, with one of the milling options (lightened) and milled for red dot (add weight) and use it with a an LWD Alphawolf compensator, 4lb striker spring and ti striker. Thoughts on how light of a recoil spring I should use (assuming I keep this as a .40S&W setup)?

    1. Me personally I woulnd’t want to go much lighter than 14 pounds with a set-up like that. I would also bet that a 14-15 pound spring would be your butter zone.

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