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Installing The Dolos Quick Detach Barrel System

The Dolos Quick Detach Barrel System is one the most revolutionary Ar 15 parts we’ve ever seen. It takes the modular AR 15 and makes the black rifle even more customizable, easier to use, and more compact. It allows builders to build a true takedown AR 15, allowing for barrel changes and caliber swaps in literal seconds. The Dolos Quick Barrel System has innovated and truly introduced a new concept into a boring market. If you’re intimidated by having to install it, it’s actually fairly easy.

Dolos Barrel System - Quick Detach w/ Handguard

How to Install the Dolos Quick Detach Barrel System

So to start you need a disassembled AR 15 upper receiver. Not completely disassembled, but the barrel, gas system, and any fixed front sight needs to be taken off. It’s a lot easier you use an upper with a fixed front sight, and we carry plenty of them. 

Dolos Barrel Quick Detach System Tri Lug

You’re going to need a standard AR 15 Upper Receiver and a portion of your Dolos Quick Detach Barrel System called the Tri Lug. It’s the larger, rounder piece with a locking mechanism on the bottom. This is to be placed over the section where the barrel meets the receiver. You’ll then insert the castle nut and rotate it clockwise. This should cover the face of the receiver. On the back end of the Tri Lug are three set screws. Just use an Allen wrench to secure these set screws. A little LocTite is also helpful. 

Dolos Quick Detach Barrel System Castle Nut

Then, take a screwdriver and push the castle nut until it’s as tight as it can be. You may want to tap it with a light tool. Nothing too hard, just a tap to help it move until it’s nice and tight. After that, double check those set screws. 

Barrel, Gas System, and Lock Collar

Dolos Quick Detach Barrel System Lock Collar

Gather your barrel, gas tube and block, and your lock collar. Slide the lock collar over the barrel, threaded end facing the barrel, until it reaches the end. If you inspect the lock collar you’ll see a hole in it. This hole is where the gas tube will go. It needs to be positioned at the 12 O’clock position. The collar free floats so it’s not hard. Then run the gas block and tube down the barrel, ensuring the gas tube goes through the hole. 

Now insert the barrel into the upper and ensure the gas tube and collar is aligned with the gas port in the barrel. Once it is, tighten down the gas block. Once the gas block is in place and tightened down you need to go ahead and install the handguard. Make sure the lock is engaged on the Dolos Quick Detach Barrel system. To do so all you need to do is thread it on and you are done. 

You’ve successfully installed your Dolos Quick Detach Barrel system! If you’re unsure of any steps we described above, here’s a great video on the installation process. 


DISCLAIMER: If you are new to the world of DIY gun building, you likely have a lot of questions and rightfully so. It’s an area that has a lot of questions that, without the correct answers, could have some serious implications. At AR-15LowerReceivers, we are by no means providing this content on our website to serve as legal advice or legal counsel. We encourage each and every builder to perform their own research around their respective State laws as well as educating themselves on the Federal laws. When performing your own research, please be sure that you are getting your information from a reliable source.


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