There was a recent thread on using Mobil 1 (can't find it) where I asked if using Rotella T was a good idea with pertinent regard to cleaning, as one gentleman pointed out that diesel oils often have more detergents to prohibit carbon build up. I run Rotella T in my truck, and I like getting multiple uses out of things, so I tried it today.




Rifle was an FN A2 clone, and it ran flawlessly. I coated it heavy to begin with, and it remained good and wet at the end of the day (280 rounds). I specifically ran the bolt very wet, to include the rear of the bolt near the gas rings where you get the most carbon build-up. I understand 280 rounds is not a thorough test, but my initial impressions were that while it didn't "prevent" buildup, it did seem to help make it easier to clean afterwards compared to if I had used standard CLP.

Upon removal of the bolt, as mentioned, it was still good and wet. Very adequately wet, similar to the way Slip 2000 stays wet for you. There was indeed carbon build up at the rear of the bolt, but something looked "different" about it than normal. It was more "fluffy" looking than "caked on."




With a scraper tool, I gave it one swipe and it was like a warm butter dish. Crap just came right off. I realized I didn't need the tool and gave it a wider "scrape" with my fingernail (more like a "wipe"). In my previous experience when just using CLP, using a fingernail to "wipe" it away wasn't possible after +/- 300 rounds. Even with that little a round count, there's usually enough caked on there you kind of need a tool or brush plus some scrubbing.



To spare my beautiful modeling hands I used a scraper tool to move away the rest of the big stuff, then used a USGI nylon brush with a little CLP to "clean". The carbon that did "stick" came right off without any effort.



Does 280 rounds in a rifle-length gas gun comprise a legitimate test? Hell no.
Are there other products or oils out there better than CLP that would likely have these same results? Most definitely/probably, but I've only tried Rotella for this purpose. (Of note, Lucas upper cylinder lubricant works great as lube, and Pennzoil 5w30 out of a dipstick will work in a pinch, but that's as far as I can comment on the matter in terms of non-gun specific operating oils)

Regardless, clean up today was a cinch. I will be using Rotella T to test further (probably push cleaning out to say 2k?) but my initial impression is that it will make extended operation in a semi-auto gas gun much more easy come cleaning time. Plus, it's a lot cheaper per ounce than Slip 2k

Oh, and the chamber area was a breeze to clean. CLP, Q-tip, done.

The only negative I saw was that there was a little more oil in my buffer tube than I would have liked, or am used to seeing when using CLP or Slip 2k. (Though this could have been related to me practically dunking the bolt in Rotella)

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Update: 09APR2014

Went out to the range and ran the A2 a little today. I fired 180 rounds of M855, and again the rifle functioned flawlessly using Rotella. Only down side of note was a bunch of oil getting blasted through the gas tube hole at the front of the receiver. I suspect by 2k rounds, the rifle is going to resemble the lower portion of my GM 6.2 diesel :)

When I got home to open up the guts and have a look, the bolt looked very similar to the initial test, though not as much "caked" carbon. Trying not to "clean" the bolt, but touching it yielded the same results--the carbon just wiped away. (Cool!)

The bolt carrier itself I noticed had all the carbon suspended in the oil toward the direction (of gravity) of how the rifle was sitting in the case. Just touching it, the carbon could be wiped away resulting in a dark mess on your finger tip, but the metal underneath looked great. This is not dissimilar to what you might see with another low viscosity (compared to gun lube) oil, and it got me thinking....

I have to keep lubing the rifle to fire it. I'm not trying to attempt "Filthy 14" here, I'm trying to determine if using Rotella as an operating oil will help with cleaning when the time comes to do so. Problem is (or rather, the cool part is), when you apply fresh Rotella to the places it needs it, it just ends up wiping the carbon away. In other words, the carbon is not sticking to the bolt. It's building up in the places it should be, but application of fresh Rotella to those places just brushes it away. (Awesome, right?)

So I'm going to modify the game here. I'm not going to "not clean" the rifle for 2k rounds. I'm going to leave it as I find it after every shoot, and just apply fresh Rotella to the places I need as lubricant. Now the bore and chamber, I do want to clean those to some degree. At least the bore. So on the places I do want to clean, why not use Rotella? In this way, nothing comes in contact with the rifle for 2k rounds except the oil I'm testing. It eliminates "cross pollination" so to speak. So from here forward, I will be cleaning the bore with Rotella, and to some degree the chamber, but I'm not going to try very hard. Basically a quick application of "yep, she's clean........go shoot it" will do. The bolt will continue to be lubricated with Rotella, but not cleaned or scrubbed in any way. Basically, whatever friction is caused by my finger running Rotella on the bolt will be all the "cleaning" it gets. I'm not wiping anything away with a paper towel, etc. I'm only "adding" oil as needed. If I get carbon on my hands by doing so....relax, this isn't scientific.

The ultimate result here, will be to see if a rifle ran on Rotella really does capture and suspend carbon to make parts easier to clean when it's needed *as compared to CLP, or other oil used as operating lube*. The secondary focus will be, can a rifle be run on Rotella for an indefinite period of time with little maintenance and continue to function, and if so, what are the effects if any? (I suspect already the answer to the latter is a very resounding "yes", and the effects will be "this thing is easy as hell to clean")

It would be very cool to discover that one could run their rifle on an oil that is very cheap per ounce, widely available throughout North America (in any fricken Walmart no less), use it as an operating oil, and all the while reap the benefits of it's detergents to the point that when it comes time to clean, one could probably use the same oil to clean it! Because as much as I like CLP for general cleaning, and "coating" parts for storage, the reality is (in my limited experience) that CLP sucks for operating oil. It just sucks....maybe this could be an alternative?

I should probably note the following as well: The oil didn't "run" down the bolt carrier. It stayed exactly where I applied it, and even after 180 times of violent reciprocation back and forth it didn't bleed elsewhere, or end up in my buffer tube. Indeed, the rear portion of the carrier (which I never lube) was as dry as when I put it in. Which leads me to my next item of note: It was probably 50 or 60 degrees and sunny today. This oil is designed for engines that operate at 170-220 degrees water temp. I am wondering if when the weather gets cold again, will this have any ill effects on cycling of the action in lower temperatures? When it got to -30 here this winter and my truck said "fuck you, I'm not cranking over" with this oil in it.....well, I guess we'll cross that bridge when we get there in a few months. I may have to hook up a block heater to my rifle before firing it in winter.

OK on with the photos:

Here's the bolt fresh out of the upper after 180 rounds of M855, lubed inside and out with Rotella T: (Note the carbon suspended in the oil appearing as milky black swirls)




Compare with the last photo of the bolt, this photo shows just rubbing on fresh Rotella with my finger, and NOT scrubbing or cleaning of any kind. I can't help it if the carbon builds up on my finger!


Looking inside the carrier, you can see some flaky bits of carbon, similar to the fluffy "cake" that was initially witnessed:




Bore cleaning will consist of one patch soaked in Rotella, and one (maybe two) dry patches to clear it out:


Now how does this look any different than CLP?


More to come as I find time to escape to my home away from home.....


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Update: 18APR2014

More range time today. Fired 200 rounds of M855.

As per protocol, I dabbed a bit Rotella on the bolt near the gas rings, and a quick dab on the side (didn't need much) of the carrier. Here are the photos after opening it up. At this point, there are 660 rounds of M855 through the rifle without cleaning or wiping the bolt, just adding Rotella:





As you can see, the carbon is starting to build near the gas rings. Everywhere else, it's suspended in a milky, disgusting Rotella mix of goodness. And yet again, in the next photo you can see what dabbing just a bit of Rotella does on the bolt: a crap ton of carbon is picked up on my finger in a gooey mess.



While it looks like it's sticking to the bolt, my honest suspicion is it's not. It just comes off way too easily. If my finger pulls that much carbon off just by dabbing fresh Rotella on the bolt---I mean, hell....no way that crap is sticking. We'll see...1400 more rounds to go.

I should also note at this point that the chamber area and up by the gas tube is not caked in carbon at all. In fact, it looks like it doesn't even need cleaned. Then again, this is a soft shooter with a rifle length gas system... I can tell you, that my OCD is killing me. I'm one of those freaks that enjoys cleaning firearms, and I want to hurry up and blow through another $500 worth of ammo just to finish this damn test. I *NEED* to clean that bastard.

Another thing I'm finding quite interesting, is that this is the smoothest racking AR I've ever felt. Even nickel boron coated BCG's don't feel this nice. I can't really quantify this experience to you, but it just feels like butter running the charging handle on this rifle. Keep in mind, too, that this is a brand new build. It had a couple hundred rounds through it using Lucas Upper Cylinder Lubricant as it's first lube oil, then this test began. When new, it had that gritty feel of fresh anodized aluminum (you know what I'm talking about). I find it typically takes about 500 rounds to get that worked out, but man...within the first 250 rounds this thing felt super smooth, much like a well broken-in upper (1000+ rounds). This upper has run purely off diesel lubricants it's entire (young) life. And by the looks of things, it's going to continue to do so until I shoot it out.


Summary:

-My OCD to not clean this bitch is destroying my soul
-660 total round count on a no-clean, Rotella-only diet, and it's kicking ass
-Running very smoothly (better than any other AR I've run at this round count), and not gumming up at all

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UPDATE: 20JUN2014

Well gents, I blew it. The test ended early at roughly 1160 rounds. I simply had to clean this thing or I would have to see a shrink.

A few hundred more rounds of M855 went great. Filthy, and smelling like a 1980 Peterbilt, it ran flawlessly. Then I just had to run a .22 conversion kit through it. The good news is that .22 LR through an A2 barrel will repeatedly nail hits at 200 yards on steel if you crank the rear sight up to 800m. The bad news is it really fouls shit up inside. Here is where I had my first malfunction. .22 casing got stuck between the bolt and receiver, and had to get dug out with a multi-tool. No big---keep shooting. Again. And a couple more times....

"Screw it."

Swap the bolts and fire a few cases of M855 to blow it out. The M855 cases were doing a similar deal, where they had to be yanked out of the receiver. I attribute this to the mess the .22 made, and all the sand and dust and crap that got in there. Just too filthy of an environment to work in. Had I not ran the .22 conversion kit, I'm damn near positive I could have gone several hundred (maybe more) more rounds before a malfunction with the M855.

Here's the results in photos... Total round count 1160 (including about 130 or so of .22)

Dirty girl





Notice everything is still nice and wet, though



Oh, so dirty....


Gave it all a quick wipe with a paper towel


And yet, the carbon is just caked...not "baked."



Pretty grody down there.



Pics show just using a finger nail to scrape the bolt. I'm pleased as hell.






This shit was nasty


But one scoop with the q-tip shoveled it out, just like inside the reciever


I have to say, clean up was pretty easy. I didn't have to do any "scrubbing." Everything just lifted up, or was brushed away with a q-tip or paper towel.

I wanted to draw the test out more, but the 22 kit was calling my name that day. Maybe I should have just kept going...I don't know... But this rifle is so nice (to me). Maybe I'll do another test with a beater M4.

Bottom line is, I am definitely using Rotella and Rotella only from now on as lubricant. It is cheap as hell, readily available, and works outstanding. In fact, better than most lubes I've actually tried. Cold weather will be an new test come winter time. But for summer--shit runs great. Buttery soft action. AND, most importantly, it made cleaning a breeze. I have another AR I've been shooting off and on as a "control" of sorts, just using CLP. It's a bitch to clean in comparison. Too much time scraping the bolt, whereas the Rotella mitigates that to a large degree.

I know, there is probably better choices out there to accomplish what Rotella and other high-detergent diesel oils do for gas-guns. But I know you'll pay more :)
I can run Rotella super wet, and not worry about cost. The down-side may be that just as Rotella kind of "traps" and "suspends" carbon, it does the same with dirt and debris. The 22LR accelerated that process, I believe, and then malfunctions occurred.

Let me know what you think, but for me, Rotella FTW!

For what it's worth, I've been using RP 20w-50 in one of mine for the last two years without a hiccup.

Hell yeah! Give us an update after 2000rds.
I'll probably get there before you, I'll put some on my slide ride

If you like the Rotella T, consider T-6 5w-40.  It is full synthetic and has those extra diesel type additives.  I use it in a race prepped turbocharged engine because of the extremely tight clearances and very high temperatures around the turbo center housing bearings and because the engine is direct injection, like a diesel.  I prefer it over Mobil 1.  I've not used it on an AR.  I think I'll give it a try and  see how it does.  BTW, my test may not be a valid comparison on clean up, as my BCG is NiB and it wipes off now without scraping.  But using the best available lube and running wet is the right thing to do for your rifle.

Thanks, OP for the post.

Thank you for this. I was asking about Rotella in that thread as well, since I use the 15-40 for my VW diesel. I always have some left over in a quart jug when I do oil changes.

Updated OP

I been wanting to try mobil or some other kinds of gun oil for a while now since my guns are always dry when I clean them.  I run rotella in my cummins so there's always some around and the cleaning part of diesel oil makes perfect since that it should work very good.  Think I'm gonna give this a try too.

Good info and well written.

Heavy Weight motor oils have worked great for me....until I found FireClean...its truly the most ridiculous lube I've used (meaning great)...while I do not think it offers more protection against wear than any other oil...it does run a lot cleaner

Good to know, but....

FireClean is $7.50 per ounce.
Rotella is $0.11 per ounce.

I'm looking at Rotella *because* it's cheap and *because* it's what I run in my vehicle.

Some people just don't get it...... I have been using 75% Mobil delvac and 25% atf for years (and hops #9 to clean)

Fireclean froglube etc just don't perform better enough to justify the huge price increase

I might go ahead and try something similar with my suppressed rifles. I use Slip2000 EWL, and while I love it I am running out. Since my can really gets things good and dirty, and I mean everything, I might try running some of this or something similar next time I go an burn a few hundred rounds. Went through almost 420 rds of federal last weekend, so I'm going to need some recoup time . I might need to try running it sopping wet and see how long it stays around before the BCG ends up dry again. Shouldn't be an issue with getting plenty in the barrel extension, right?

Thank you!

 

Is there anything in motor oil, like detergents, that could be harmful to the aluminum in AR receivers?  

I've been trying to figure out what motor oil would make the best alternative to traditional gun oil and so far 100% synthetic oil with a high viscosity index looks good, but I don't want to use anything that could damage metal or plastics over time.

Pictures aren't working (might be my computer), but great write up, I'll keep that in mind.

A lot of engines are made of aluminum and plastic don't over think it these rifles are a lot tougher then we give them credit for

Im no chemist, but I don't see why they would damage anything. In reality, the anodizing covering your receiver is actually harder than the aluminum itself.

I suspect we should be good to go whatever we choose.

Rotella certainly doesn't harm the aluminum heads in my pickup.

there you go.

I used castrol 20w50 in aluminum vw blocks years ago, and castrol has a lot of detergents too. It ran great.

I have been using Mobile 1 for five years currently. I have not had one single issue the entire time doing this. Some people get hung up on lubricants needing to be specifically for "firearms". The thing is, a motor goes through just as much stress as a firearm does, I just try to stay away from strong additives.

Only thing i would suspect could be a problem is if the oil got near the primers.  Oil will penetrate and foul up your ammo.  I would not use this on a self defense weapon.

 

Topic Moved

Muad, could you elaborate on this please?  (I'm ignorant)

And why would say Rotella be any different than Slip2k etc on any other primer?

He said the oil would penetrate the ammo and foul the primers. M193 and M855 have a sealed primer and projectile. This is done because it's "mil-spec" ammo. Therefore, the oil would not penetrate and foul the primer. Doesn't matter if it's Rotella, CLP, etc.

 

Ol Painless did a primer contamination test. You don't have anything to worry about with excess oil of any kind in the weapon.
After 6 weeks all his test ammo went bang.
http://www.theboxotruth.com/docs/bot39.htm

Last time I lubed my riffle I used hydraulic fluid. It's still on there two months and a couple hundred rounds later.  


Now I'm curious what my bolt looks like.

BUT HE DIDN'T TRY ROTELLA!!!!!!

Yes you're right...

EVERYONE PANIC IF YOU'RE USING RT!!!!! YER SHIT WON'T FIRE!!!

Happy?

Updated OP

Thanks for the write up. For some reason the pictures don't load for me.

Very interesting write up.  Definitely interesting.

Updated OP

Test ended early because I have no self control.

Man that was a god awful mess.

Thanks a ton for this test! I use the syn 5W-40 Rotella in my Subaru WRX STI and use the conventional 15W-40 in my work truck. I have been using this oil since 2007 or 2008 and have nothing but high praise for this oil, especially the syn oil. I sometimes send my old oil to Blackstone Labratories for a UOA (used oil analysis). This oil always performs well and at 3000 miles in my STI still has 40% life left in it, but I still change at 3,000 due to blow by in a turbo engine. I have a few gallons of this stuff put away because I buy it on sale. I also believe that there's a $5 mail in rebate deal going on right now at Wal-Mart.

PAO synthetics like mobil1 have low solvency,  in these oil threads I've always recommended diesel oils or atf (better corrosion resistance).

I thought rotella was a kind of pasta.

Best comment of the whole thread

bingo....I only use mobil 1 and my dissy had over 3k with no cleaning...ran like a top

OP, thank you and great write up

yup!

Hope not as lots of newer engined seem to be made out of aluminum.
I've been saving the last little bit of new oil out of the bottles and jugs, not yet enough for adding to the engine.
May end up earmarking it for gun lubricant purposes.

Great thread OP.

Except on some that I used Mobil1, I have mostly run diesel oil in all my engines for years. I was convinced to start using it when I tore into an old Chevy 350 with 300,000+ miles on it and the inside had very little sludge buildup in large part due to the higher detergent ratings.

Great post. You might want to invest in a trigger pump oil bottle for a few bucks. I don't have a self soiling jammomatic yet but can see how the diesel oils do a great job of keeping the carbon soft for cleanup. I use Mobile 1 on my piston guns but when I go through the quart or so I have will probably try a diesel oil. If cut with tranny fluid it might even feed through a spray bottle to keep things running wet. One day I will build up a 300 blk or a 458/500 because I am not worried about zombie poodles.

Triggers should be greased, never oiled ;)

I use motor oil a lot for  AR lube never a issue. I have used all kinds of weights they all easly make it throught a class of 750 to 1000 rounds in a weekend.