View Full Version : Corrosion & Pitting On My Bolt Assembly
Hello gents, been lurking here for a few years but rare post. My research here and abroad (online) lead me to purchasing my Daniel Defense M4 v3 mid-length gas system rifle a few months ago.
Due to financial reasons, buying the gun being one of them, I have not had the ability to shoot it too much, but thus far I've put about 350 rounds down range.
I went shooting weekend before last, put about 100 rounds down range on the AR, and about 30 for the M1A I have. I thoroughly clean my rifles after each range trip, and I am quite certain the pitting was not there.
After this weekends range trip with about 150 rounds down range, during my cleaning that night, I noticed not only pitting but corrosion on the bolt assembly (forgive me if my nomenclature is wrong).
This being my first AR, is this normal? I shot the gun very slowly at the range and it did not get too hot. I tried to clean off the corrosion the best I could, but the pitting is another story. I use CLP as well, in case anyone is wondering. So enough of my rambling, what is the verdict?
http://imageshack.us/photo/my-images/690/boltassembly121.jpg/
http://imageshack.us/photo/my-images/819/myddm4v3.jpg/
just a scout
08-31-11, 10:04
Looks like carbon build up. You could try scraping it to see if it comes off. I use an M4 tool (think it's the name) that does a great job.
Hard to see in that picture but I agree that it just looks like carbon build up. Soak it in CLP (or cleaner of your choice) and you should be able to brush the majority of it off.
Littlelebowski
08-31-11, 10:14
It's carbon and is doing nothing detrimental to your weapon. Don't buy one of those stupid scrapers; just soak in CLP, brush off what you can every 1k rds or so and drive on.
That looks like it's just baked-on carbon. Completely normal, and it usually builds up in that spot.
Check out some of the stickies that go into detail about cleaning. It'll take some hardcore scraping to get that off, but if it's soaked in CLP or cleaner it should come right off.
As others have stated this is completely normal. I would find something better than CLP and I would make sure that your BCG is wet. You don't need to obsess over the carbon. Simply soak the bolt in something like CLP, Carbon Cutter or even FrogLube and then hit it with a toothbrush.
Appears to be carbon build up to me, too. Sometimes it can deposit in such a way that it really looks like pitting.
It isn't a problem. Doesn't affect function in any way.
If you care what I (some random guy on the internet) thinks... Leave it alone. If you are really bothered by it, use an empty casing to scrape on it, being careful not to damage your gas rings.
The parts of the bolt that need to be carbon free clean themselves for the most part. a little carbon there doesn't hurt anything.
Markasaurus
09-08-11, 11:45
It is either carbon or pitting, if you leave carbon on the bolt tail for a long time eventually it WILL be pitting. Carbon traps moisture and more then one AR bolt tail has pitted from not cleaning the carbon.
Soaking it in ANYTHING does nothing to the carbon unless you scrape it too. There is NO repeat NO chemical that will dissolve this carbon. You can just use a scoth brite pad and some solvent and clean it as best you can, then forget it as the other people say. Me I use the g and g scraper tool, and this gets most of it, solvent and the scotch brite pad (I cut them into 2" wide strips). Gets it c,lean as new.
I also bought a chrome-plated bolt from Stag- the chrome plate helps cleaning a lot. Treat the carbon to make the bolt as clean as you want, if the army doesn't say scrape the bolt, Then its probably not essential!
Littlelebowski
09-08-11, 11:47
Sigh...........
I lube with Synthetic Motor Oil which drastically cuts down on Carbon build up.
Littlelebowski
09-08-11, 11:53
So odd that I shoot corrosive ammo in classes, rinse with water, and never sit there like I was in Boot Camp again, scraping ****ing carbon and.....
my bolt is not pitted.
But what would I know? It's only about 17k rounds. 2 carbine classes this year (Defoor and Vickers).
Perhaps we should resort to power tools to scrape this bolt killing carbon off?
Your bolt will not "pit" if you do not get all the carbon off. That is silly. Thousands of rounds through my carbines very little cleaning, I haven't scraped the carbon off of most of them, I did do a couple jsut cos I need to be doing something while I am watching hulu, no pitting senor, but our of curiosity, i am going to scrape the carbon off my one of my older guns right now....pause 10 min for scraping... Nope no pitting...but now i have scrape marks...LOL
So afterwards I made sure to line up all my gas ring gaps, and reinstalled the bolt. :p
We all have our crazy opinions.
You should hear my opinions on ducks and dragons, they are never in the same place at the same time, so I think ducks are dragons in disguise. :smile:
A bolt will pit, although I've only ever seen one photograph of it- never seen it in person. I believe QUIB over at Weapon Evolution has a photograph of one.
That said... I don't think it was actually causing the rifle any problems to be pitted.
It is such a rare occurrence to begin with, and on top of that I'm not aware of it having ever caused a failure... It's not anything I worry about.
FChen17213
09-08-11, 14:06
I suspect that for a hard-use carbine, you don't have to worry about pitting at all...even if you do leave carbon on it. And this is assuming that carbon will increase the rate of pitting. Why? Because by the time it's really pitted, you've already put so many rounds through it that the bolt and barrel will probably long have been replaced from wear and tear anyway.
For me, I've never had any signs of pitting leaving my guns dirty all the time.
Do you realize that you are probably ****ing your bolt up more by using Scotch Brite Pads than not?
What's so funny is that I lube the shit out of my bolt carrier group before I shoot (suppressed I might add) and I don't get much build up there at all. I wonder why?
I clean mine with a toothbrush and it seems to work prefectly fine.
I would gladly deal with a little carbon than use a Stag Arms non HP/MPI tested bolt. BWTFDIK.
It is either carbon or pitting, if you leave carbon on the bolt tail for a long time eventually it WILL be pitting. Carbon traps moisture and more then one AR bolt tail has pitted from not cleaning the carbon.
Soaking it in ANYTHING does nothing to the carbon unless you scrape it too. There is NO repeat NO chemical that will dissolve this carbon. You can just use a scoth brite pad and some solvent and clean it as best you can, then forget it as the other people say. Me I use the g and g scraper tool, and this gets most of it, solvent and the scotch brite pad (I cut them into 2" wide strips). Gets it c,lean as new.
I also bought a chrome-plated bolt from Stag- the chrome plate helps cleaning a lot. Treat the carbon to make the bolt as clean as you want, if the army doesn't say scrape the bolt, Then its probably not essential!
Knock it off braggart. :p
So odd that I shoot corrosive ammo in classes, rinse with water, and never sit there like I was in Boot Camp again, scraping ****ing carbon and.....
my bolt is not pitted.
But what would I know? It's only about 17k rounds. 2 carbine classes this year (Defoor and Vickers).
Perhaps we should resort to power tools to scrape this bolt killing carbon off?
Grinding wheel works for me :blink: :lol:
Perhaps we should resort to power tools to scrape this bolt killing carbon off?
Can we see the pic? Specs on this? Round count?
A bolt will pit, although I've only ever seen one photograph of it- never seen it in person. I believe QUIB over at Weapon Evolution has a photograph of one.
This thread made me curious, so I took this pic when I got home:
http://i240.photobucket.com/albums/ff122/jet1966/ARMods/A2Bolt.jpg
That is a bolt from my mid 90's AR15 A2 'Gov't' model rifle (large front pivot, small FCG pins, no bayonet lug, GSXXX ser. no.) that has thousands (easily well over 10k) of rounds through it. Definitely some carbon build up, but the rifle it runs in has performed about as flawless as it gets, with the only failures I know of having been ammo related. No 'pitting,' either, unless it's buried deep under that black caking. :D It gets cleaned after every range day, but nothing more than a dousing of cleaner and some quick strokes from a toothbrush. Everything is then re-lubed, re-assembled, and put away.
The flash + my contrast/brightness/shadow tweaks gives the rest of the metal that greenish and almost brownish/rusty hue, but to the naked eye under good light, it just looks like regular Colt blackish/phosphate finish and silver showing through the wear points. I altered it to better show the contrast between the 'clean' bolt surface and the carbon build-up.
Littlelebowski
09-08-11, 16:53
Can we see the pic? Specs on this? Round count?
Plenty of info here (http://rationalgun.blogspot.com/2011/08/vickers-tactical-advanced-carbine-and.html)
Round count is about 17k rds of Sov mil surp.
So odd that I shoot corrosive ammo in classes, rinse with water, and never sit there like I was in Boot Camp again, scraping ****ing carbon and.....
my bolt is not pitted.
But what would I know? It's only about 17k rounds. 2 carbine classes this year (Defoor and Vickers).
Perhaps we should resort to power tools to scrape this bolt killing carbon off?
I hear a sand blaster makes quick work of it! :no:
That's carbon; if you don't have the money to buy a CAT tool, use a .45 casing and it will scrape that carbon off easily.
Plenty of info here (http://rationalgun.blogspot.com/2011/08/vickers-tactical-advanced-carbine-and.html)
Round count is about 17k rds of Sov mil surp.
Sorry LL I was referencing this when asking for pics and further specs. But thanks anyway for the link
A bolt will pit, although I've only ever seen one photograph of it- never seen it in person. I believe QUIB over at Weapon Evolution has a photograph of one.
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