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View Full Version : Moly lube - revisited


Benellishooter
01-06-2006, 8:16 AM
Bill's moly lube thread took a tangent.

I spoke to Bushmaster about the use of moly lube on the buffer tube this morning. They said that they do not use it when they assemble rifles because they are concerned that the lube could cause the buffer tube to vibrate loose. They say they do recommend it for match triggers.

Bill, do you have any comments? I am rather new at this AR stuff and in the process of learning. I have their DVD. As you mentioned, it is not used on the DVD.

delloro
01-06-2006, 11:06 AM
1) you are asking a poster to improve upon a major manufacturer's advice?

2) Bill will just ask Bushy, see his pre-hijack post....

bwiese
01-06-2006, 11:35 AM
Hi, Dave....

I spoke to Bushmaster about the use of moly lube on the buffer tube this morning. They said that they do not use it when they assemble rifles because they are concerned that the lube could cause the buffer tube to vibrate loose. They say they do recommend it for match triggers.

Bill, do you have any comments? I am rather new at this AR stuff and in the process of learning. I have their DVD. As you mentioned, it is not used on the DVD.

I had their videotape made in late '90s. Same thing (starring Israel Anzaldua, their LEO/mil sales director now?) Nice guy, and he knows his ARs, but they really should have a scripted presenter doing it. Hollywood he'll never make :)

Other mfgrs use lube here. Bushy has its own opinions, apparently. When I took my Colt Sporter apart there was definitely some black goop there.

Given that Bushy doesn't coat/park/finish the barrel under the area where the front sight/gas block goes on, that's a bit of a departure too from 'milspec' - and definitely a cost-savings one. Fine for a range gun, and I even own several Bushy uppers. But that's something I don't like either.

Bushy may be producing so many ARs that they don't consistently torque things down - and/or sometimes overtorque. In fact it is - or at least was - quite common for Bushy bbls to be overtorqued enough that the front sight was canted a bit (though stil in-spec in terms of # of clicks to zero), and the index pin was under a lot of stress or sheared off. Many folks sent their uppers/rifles back to Bushy for this esp in 1998-2000, and this seems to be one of the prime complaints (the other one: purplish haze in finish, resulting in what many term "Barney" rifles.)

Given their apparent lack of control here, combined w/rapidity of production, it could be that receiver extensions ("buffer tubes") can indeed loosen when undertorqued. However, staking (i.e, distortion of an edge-to-edge interface with a punch strike) can prevent this. I believe original Colt ARs and M16s are also staked - dunno about current production Colts.

Discussions w/knowledgable folks on the AR15-L mailing list also revealed that some of the torque specs used and deriving from the military manual may have just been derived from taking functioning rifles off a rack and disassembling with a torque wrench and using that number. If you want to torque a bit tigther, by all means do so.

Frankly, this concern also appears more relevant for A2 fixed stocks than for CAR-stylestocks, the latter of which both thread into the lower receiver and also have a ring nut that needs to be tightened down (and, ideally, staked). I really like the new ring nuts (the ones that come with VLTOR stocks, for example) that have multiple deep cutouts in them (castle nuts?) for the new CAR stock wrenches - instead of the old ring nuts that have one notch in them and use the common/older 'hook' style CAR stock wrench that just grabbed onto this one notch. Never felt that I could get a great amount of tightening on these, so staking was important.

The other factor that's important here to Californians: these lowers are politically irreplaceable in CA. So it'd be a shame to have, after 10 years, a receiver extension tube 'freeze up' in the lower and causing thread damage. I'd rather take the ever-so-light chance of loosening tube, which (as you can tell) doesn't seem to worry me that much since really I whale down on 'em when I mount my stocks (and I don't use a torque wrench).


1)you are asking a poster to improve upon a major manufacturer's advice?
2) Bill will just ask Bushy, see his pre-hijack post....


Opinions vary. For this reason I stick with the USGI tech manuals. There doesn't seem to be a problem with the data gathered there, and I believe the US military services/maintains many more rifles run in harsher service than Bushy's warranty dept does.

No, I won't ask Bushy, because I have info from other trusted sources :)

BigAL
01-06-2006, 11:46 AM
The other thing Bushmaster does on collapsable stocks is use loctite on the castle nut instead of staking it. I damn near had a hernia trying to take one off and destroyed the threads on the buffer tube before :( I realized what was going on and got the heat gun. Came right off after that.