Ruger AR-556 Model 8514 w/ 18" barrel

Trying to clean the exterior of the barrel.

I've been reaching through the guardrail with Q-tips to remove whatever dirt I can from the exterior of the barrel and gas tube.  I probably need to meet with my gunsmith in learning how to take the guardrail off.

In the meantime, should the outside barrel be lubed?  If so, could I spray Ballistol through the guardrail holes onto the exterior barrel and be okay with that?

What do you guys do and what should be my concerns?

Thanks

Loosen/remove those two hex key bolts on the bottom of the hand guard and you should be able to remove it.

From Ruger forum

Handguard is threaded to the barrel nut.  Watch this vid.

Loosen the 2 hex bolts on the bottom of the handguard just forward of the mag well. The handguard/rai!s will then simply slide off the barrel nut and over the barrel and gas block. It is not threaded to the barrel nut.

Clean everything up then slide it back on, line up the top rail with the upper receiver rail and tighten the 2 bolts.

That's what I do with my AR556 MPR.

Outside of barrel and  gas block do not require lube but a light coating of protective anti rust oil. The P in CLP.
I just put a few drops of oil on a cleaning patch or corner of a rag and wipe the exterior metal down leaving a very thin film.

It's a nitrided barrel so your worries are much less.

Hose it down with some Ballistol or G96 aerosol and forget it.

Hose it off or take in into a hot shower.

You’re probably worrying about something you don’t need to worry about at all, barring some kind of exigency circumstance.