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Dolos Quick Detach Barrel System FAQs

Frequently Asked Questions about the Dolos Quick Detach Barrel System AR-15

Q: Do you have install instructions available?

A: Yes, we have installation instructions which can be found here. We also have a parts drawing which can be found here.

Q: Can I use the Dolos with a billet upper receiver?

A: The Dolos was designed using mil-spec drawings and measurements of upper receivers. Since many billet uppers are designed with external dimensions larger than mil-spec, the tabs on the back of the tri-lug assembly, or the receiver, may need to be modified to fit. It is possible to install the system with the tabs removed.

Q: Does the Dolos work with any gas tube length?

A: The Dolos can be used with any standard length DI gas tube: pistol, carbine, mid, or rifle length.

Q: Can I use the Dolos with a piston upper?

A: The Short answer: NO. The height of the gas block does not allow enough clearance for the handguard to be installed.

Q: Can I build an AR in any caliber with the Dolos?

A: Any caliber that can use a standard AR15 mil-spec, forged upper receiver can benefit from using the Dolos. We have had customers piece together .458 SOCOM and .50 Beowulf uppers with the Dolos installed without issue.

Note: Please remember that the larger bore calibers require a wider ejection port opening to function properly. Be sure that your barrel diameter is 1.000 inches or less.

Note: For blowback calibers (dedicated .22LR, 9mm, etc.) it is recommended that a faux gas system be installed. By faux gas system we mean a gas tube and gas block that will exist solely to retain the lock collar. Not using a faux gas system will allow the lock collar to spin freely and possibly slide off the end of the barrel when not attached to your upper.

Q: Can I combine my heavy barrel with the Dolos Barrel System?

A: As long as the diameter of the heavy barrel is 1.000 inches or less, then you can use it without issue.

Q: Will any brand upper, barrel, etc. work with the Dolos?

A: The Dolos was made to replace the barrel nut on an AR/M4 with mil-spec components. We recommend reaching out to the manufacturer, since not all manufacturers use mil-spec dimensions in the creation of their products it is best to contact them to see if the item in question is made to mil-spec dimensions.

Q: What parts do I need to add a second barrel/caliber?

A: You will need a Dolos standard lock collar and a handguard. 

Q: What handguards work with the Dolos?

A: A list of compatible handguards can be seen below.

The rails and handguards listed below are compatible with the standard (1.850-30TPI) Dolos/Prometheus lock collar. (Some may require modification)

Rock River Arms DLX Series

Rock River Arms NM TRO Series

Rock River Arms TRO Series

Rock River Arms Aluminum Quad

Rock River Arms Aluminum Half-Quad

YHM Diamond Series

YHM Smooth Series

YHM Todd Jarrett Competition Series

YHM Free Float Tubes

YHM Customizable Free Float Tubes

YHM Keymod Rails, KR7 Series Only

YHM M-Lok Rails, MR7 Series Only


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