How to Lube an AR for Maximum Reliability

Cam Channel and Cam Pin

Slather the entire channel and the upper half of the cam pin. Slather – especially when running suppressed. This is an area of tremendous – and unrecognized – friction and mechanical disadvantage when the cam goes to cam-over at the cam-shoulders. It also has 700F-1500F gasses pumped into it, full of friction contaminant, almost directly from the gas tube as the BCG pulls back – this cooks off and/or blasts away gun oils, while packing it with super-heated friction contaminant – creating a tacky abrasive right on those cam shoulders and the cam pin.

When bolts break at the cam-pin hole, it’s because of this – the tremendous torque that’s being applied to it, because of the friction on the cam shoulders. So, lube heavy, and slather the grease in the channel.

Bolt Carrier

Fully coat the 4 rails and sides of the gas key if rub wear is present. For max reliability, lube heavy – with oils, the wetter the better, up to the point where the lube may get into the mag, which you do not want. With our grease, a thick coating on these bearing surfaces.

Upper

Coat the 4 opposite mating surfaces on the upper where BCG rides – yes, lube both mating surfaces (carrier’s and upper’s), including the entire length of the upper, to ensure sufficient lube and no dry contact surface, and to help with the sealant effect.

Gas Rings and Bolt Tail

Leave dry, do not lube – the gas is direct, under pressure, and far too hot for any lube to endure long enough to matter, and the friction surfaces are not large enough to be significant in the total amount of friction surface in the gun to matter, if everything else is properly lubed.

Extractor

Nothing on the claw face that may contact the casing. Lubing the pivot pin is debatable, but would require disassembly to apply our grease.

Locking Lugs

There are few situations where lubing AR locking lugs will enhance reliability to be worthwhile, over the risks that come from lubing them, so leave dry. The primary risk comes from lubes heated beyond the point where they begin to break-down and polymerize, and then start cooling – it can create a tacky substance. And for fresh guns that need first-round reliability, the rest of the gun will have so little friction from being properly lubed that it does not provide enough added benefit. Readers are welcome to contact us directly if they’d like details on when it may be worthwhile.

Never lube, on any gun, without exceptional and clear need to do so (i.e., rust), for three reasons:

1. There simply is not enough friction between firing pin and channel, compared to the energies applied by the hammer, to require lube at all
2. The energies applied by the hammer will displace or crush sand or dirt that may get in to the firing pin channel if dry, but a wet pin may retain enough sand to be too much to displace or crush,
3. Firing pins are usually the first place a gun will shut down in cold weather. One drop of oil is enough to create contact between pin and channel almost the entire length of the pin – and when cold enough, any lube will go from reducing friction, to acting like an adhesive. This channel is also extremely challenging to clean lubricant out of fully, down to bare metal, making it subject to freezing even if the shooter thought they’d cleaned it out well. Combined, always run firing pins dry, unless presented with a very serious and clear need to lube it, such as rust.

1. In complete opposite of the action, mags run best dry, and worst wet, and have a very narrow window of reliability between energy and friction – the energies of the springs compared to the resistance of the ammo and follower are narrow, because if too powerful the action would have a hard time stripping each round during cycling, and too light the springs wouldn’t move the ammo fast enough. Being of looser tolerances, if dry, sand will tend to want to drop below the follower during cycling. But if wet, it may stay in place and accumulate, adding enough friction to overcome the narrow window of reliability.
2. Different geometries and energies mean different friction experiences – the fast speed of an action, combined with tight, long geometries, can allow a single piece of sand in an action to cause binding, while slower mag followers with shorter and looser friction-surface geometries may not experience such binding, and can handle a little dry sand. But by adding just a little lube, that sand can add up enough friction to keep the ammo from moving fast enough up the mag.
3. Lube on ammo will virtually guarantee sand sticks to it, and cause a malfunction in the chamber during chambering if sufficient enough.
4. Lube on ammo can dramatically increase the pressure on locking lugs. When ignited, the gasses treat the bullet and casing equally, trying to turn each into a projectile out either end of the barrel. Casing brass, however, being soft, first expands against the chamber walls during firing, serving to seal off the chamber from expanding gasses, and also creates a significant amount of friction against the chamber wall that would otherwise be directed into the locking lugs of the bolt. Lubing a casing plummets that friction, and can increase pressures on the bolt lugs by up to 40%, depending on cartridge design.

Bore, Chamber and Ramps