View Full Version : Steel barrel nut ?
Just wondering because WOA has their own pinch/clamp rail that uses a longer steel nut.
I heard that dissimilar metals “promotes” corrosion. (galvanic?)
Weighs more than alum
Stronger = better than alum nut? (less rail flex?)
I assume this is what they use on their uppers and my understanding is their stuff can shoot.
Just wondering if it makes a difference at shooting longer distances. May try one on a future build (Valkyrie)
My last build has an alg rail...I believe the nut was aluminum.
The original barrel nut is steel so whats the difference?
I don’t know myself
It seems that a lot of the proprietary barrel nuts are aluminum
My cheap bca used a steel barrel nut (probably made in China)
Alg uses aluminum
I believe Gissele uses aluminum
I don’t know what psa uses but kotaboy (YouTube) shot a Grendel pretty well.
If the material for the nut doesn’t matter I’ll probably try the rail from WOA with the steel barrel nut and “pinch” rail
I heard that dissimilar metals “promotes” corrosion. (galvanic?)
Thats why the spec says to use Aeroshell 33MS on the barrel nut to upper receiver threads... problem solved...
Thats why the spec says to use Aeroshell 33MS on the barrel nut to upper receiver threads... problem solved...
Actually, even without grease there wouldn't be and galvanic corrosion, as long as the anodizing is kept intact. Anodizing produces an aluminum oxide layer that has the same insulating properties as glass.
And another thing, in order for galvanic corrosion, an electrolyte (water) has to be present, so as soon as you shoot a few rounds and heat things up, the problem disappears.
Rjacobs/Lysander,
Thanks!
I’ve built an upper before and used aeroshell. When I read a post about dissimilar metals corrosion it got me wondering. I thought that somehow with the torquing there might be some metal to metal contact.
I’ll keep an eye on a WOA rail for my next build.
P2Vaircrewman
04-22-20, 09:02
Seems to me the Aeroshell 33MS is more about getting the correct torque and preventing galling than corrosion. As was said an electrolyte such a water, salt water is the worse, must be present for galvanic corrosion to occur.
vicious_cb
04-22-20, 16:05
Or just drop the cash and go titanium and not have to worry about it. :rolleyes:
m1a_scoutguy
04-22-20, 16:48
This looks pretty handy ! https://www.amazon.com/Aeroshell-Specifically-Builders-MIL-G-21164D-4oz/dp/B00WOJPWNK Just the perfect size for probably a lifetime !
titsonritz
04-22-20, 17:12
This looks pretty handy ! https://www.amazon.com/Aeroshell-Specifically-Builders-MIL-G-21164D-4oz/dp/B00WOJPWNK Just the perfect size for probably a lifetime !
I like this one...
https://www.amazon.com/AEROSHELL-33MS-Synthetic-MIL-SPEC-Barrel/dp/B01M5J6J0A/ref=sr_1_1?dchild=1&keywords=aeroshell+33ms&qid=1587593311&s=sporting-goods&sr=1-1-catcorr
m1a_scoutguy
04-22-20, 18:05
Good point, better to have too much than not enough! That really should last a lifetime!
Or just drop the cash and go titanium and not have to worry about it. :rolleyes:
Actually, titanium and aluminum are at opposite ends of the galvanic series, are more reactive, and are more likely to corrode than aluminum and steel.
:blink:
vicious_cb
04-22-20, 22:46
Hmm should I be worried? :confused:
I built my first upper receiver back in 2019 and I used a steel barrel nut and I used Aeroshell 33MS grease. I was worried about using proprietary aluminum barrel nut instead of a steel barrel nut. I put a Troy Industries rail on my AR that fits a standard barrel nut.
Hmm should I be worried? :confused:
If you plan on storing your upper in salty water, yes, otherwise, no.
vicious_cb
04-24-20, 00:13
If you plan on storing your upper in salty water, yes, otherwise, no.
Whew, had me worried there. Love me some Ti barrel nuts. 4x the price, 1 oz in weight savings.
If you plan on storing your upper in salty water, yes, otherwise, no.
Direct bare contact in a humid environment is a non-issue?
Edit: to clarify, I’m thinking about pistol and rimfire suppressors that mix aluminum and titanium parts.
You do realize that your steel barrel is inserted into an aluminium receiver right? No issues using aluminium barrel nut.
That is true, good point. The anodizing inside is usually also still intact when the barrel is installed.
I don’t know myself
It seems that a lot of the proprietary barrel nuts are aluminum
My cheap bca used a steel barrel nut (probably made in China)
Alg uses aluminum
I believe Gissele uses aluminum
I don’t know what psa uses but kotaboy (YouTube) shot a Grendel pretty well.
If the material for the nut doesn’t matter I’ll probably try the rail from WOA with the steel barrel nut and “pinch” rail
The original/standard is steel. Geissele used to use both, not sure if they still do. Some hard core old timers might argue for steel. Personally, I use steel with handguards that use steel and aluminum with handguards that come with an aluminum nut. I treat them the same, and I've not heard of any problems with them when installed properly.
You do have to use a graphite free anti-seize grease on the threads. IIRC Yeah, everyone uses Aeroshell 33MS, its got lithium and molly in it. Really stinks like hell too.
The time you get galvanic corrosion is when water, especially salt water, gets between the steel barrel nut and aluminum receiver, and it can be bad, but won't happen if you properly assemble the rifle. Most of us are not SEALs anyway, lol.
People, correct me if my memory is failing.
I like this one...
https://www.amazon.com/AEROSHELL-33MS-Synthetic-MIL-SPEC-Barrel/dp/B01M5J6J0A/ref=sr_1_1?dchild=1&keywords=aeroshell+33ms&qid=1587593311&s=sporting-goods&sr=1-1-catcorr
Way back, 8-9 maybe 10 years ago, when, I think it was Noveske, let it be known that thats what he used, you couldn't buy Aeroshell 33MS in little repackaged amounts. Its used on Aircraft, so I had to buy it from an aircraft maintenance outfit, and I had to buy a whole tube like you'd use in a grease gun.
After building and rebuilding 12 rifles over the years, I still have a little less than 3/4 of a tube of it, even though I use it on others stuff too. LOL A little goes a long way (maybe over 20 builds, including friends).
Hammer_Man
04-24-20, 14:26
I used to be really particular about using AeroShell, but I've switched to a generic Valvoline Molybdenum grease for my most recent builds. I picked it up for cheap at an auto parts store, I figured I'd give it a try. I don't plan on swimming in salt water with my guns at any time, so I think I'll be OK.
There are steel-Al interfaces all over the gun.
Its not an issue.
titsonritz
04-25-20, 00:21
Whole wants to deal with the weight of a steel Geissele barrel nut?
titsonritz
04-25-20, 00:26
Way back, 8-9 maybe 10 years ago, when, I think it was Noveske, let it be known that thats what he used, you couldn't buy Aeroshell 33MS in little repackaged amounts. Its used on Aircraft, so I had to buy it from an aircraft maintenance outfit, and I had to buy a whole tube like you'd use in a grease gun.
After building and rebuilding 12 rifles over the years, I still have a little less than 3/4 of a tube of it, even though I use it on others stuff too. LOL A little goes a long way (maybe over 20 builds, including friends).
LOL, I did that with a tube of Aeroshell 6 and split it with my dad, still have enough trigger grease for 30 lifetimes.
Direct bare contact in a humid environment is a non-issue?
Edit: to clarify, I’m thinking about pistol and rimfire suppressors that mix aluminum and titanium parts.
There has to be an electrolyte in sufficient amounts to complete an electric circuit. Humidity is not going to conduct electricity unless the voltage is in the thousands . . .
And both parts are anodized, so there is also a good insulator between the metals.
There has to be an electrolyte in sufficient amounts to complete an electric circuit. Humidity is not going to conduct electricity unless the voltage is in the thousands . . .
And both parts are anodized, so there is also a good insulator between the metals.
Thanks. I’m looking into using aluminum for some of the baffles in some Ti tubed Form 1s I have planned. I’ll see about anodizing.
You do have to use a graphite free anti-seize grease on the threads. IIRC Yeah, everyone uses Aeroshell 33MS, its got lithium and molly in it. Really stinks like hell too.
Why no graphite?
Why no graphite?
Its conductive and could speed up galvanic corrosion.
Its conductive and could speed up galvanic corrosion.
Not quite that simple. We have established that galvanic corrosion is not a major problem due to 1) the heat of operation tends to drive off any water (electrolyte), 2) the anodizing is a very good insulator.
So, why do military dry film lubricants and greases specify "no graphite"?
From "Dry Film Lubricants and Corrosion", published by Rock Island Arsenal:
Graphite and molybdenum disulfide have been studied in detail by many workers. It is now definitely known that an absorbed water vapor layer is essential for graphite lubrication. If this water vapor layer is removed, either by high temperature or vacuum conditions, the graphite loses its lubricating properties and becomes quite abrasive.
If an abrasive is introduced in a threaded fastener, you will get fretting and a loss of the protective coatings of both the aluminum and the steel. Further, graphite is mildly hydrophilic, so it attracts moisture. Even if the aluminum is still insulated by the anodized layer and not subject to galvanic corrosion, the steel will suffer from just regular corrosion due to moisture.
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