The AR platform has a reputation for not operating reliably without regular cleanings- every 1000 rounds is a common interval. While this can be true with off-the-shelf configurations, a few simple drop-in upgrades can strengthen the rifle to ensure reliable operation for at least 80 standard capacity mags (2400 rounds) running the rifle dry. With a modern lubricant that will run dirty you should be able to get closer to 3000 rounds or beyond. Let’s start with the explanation of the problem source…
The popular myth is that the direct gas impingement system causes AR platform rifles to foul up by leaving powder and gas residue in the action (take a look at how it works and you can see how that seems plausible). Over time this supposedly results in fouling of the bolt and bolt carrier which manifest as failures to eject or to go into battery. Installing a heavier buffer, stronger action spring and a stronger extractor spring will take care of these problems by keeping the action working properly even as fouling occurs. The cost of these upgraded items is under $30 (plus shipping) if you go with the Sprinco enhanced reliability kit and a cheap H2 buffer from Amazon.
An H2 buffer and the Sprinco blue spring from their enhanced reliability kit are what I used in my rifle. That part doesn’t really merit photos- press the plunger down to release the buffer and spring and replace in the opposite order. The extractor spring was more interesting photo material so here is what you need to do to install it.
Disassemble your bolt carrier group the same way you would for maintenance:
Disassemble the extractor from the bolt like you would for normal cleaning (ignore the cam pin or set it next to the bolt if you insist on following directions to the letter):
Use a pliers to remove the O Ring from the extractor:
Now carefully remove the extractor spring and insert by twisting it counter clockwise and pulling:
Set the old extractor insert, spring and O ring aside and insert the new extractor insert, wider side down, into the extractor. Place the spring on top of it and press both into place using a pliers (wrap the ends in electrical tape to soften the grip area- even though the photos tell a different story).
Now replace the O ring and reassemble your bolt and the BCG (Bolt Carrier group). You may need to use the pliers to hold the extractor down now to replace the extractor pin- and that’s good because you now have a stronger extractor spring working to eject empty cases from your rifle. Here is a side by side comparison of the springs (Sprinco on the left and standard on the right):
This upgrade and a high performance lube like Frog Lube should be all you need to keep your AR running reliably through any extended use period. If you need to run it for more rounds without maintenance then there are bigger problems underfoot than a dirty rifle.