Help: Rust/Damage on exterior of AR Barrel?
- Thread starter cdnskier
- Start date
Disregard all the advices of pulling the gas block and doing funky things.
The gas block looks factory. The fit between the barrel and the gas block is not very tight, but the carbon is sealing up the gap anyways.
Is this normal - not really. If this is a brand new rifle straight from the factory, I will call LMT and make them sort it out.
The gas block looks factory. The fit between the barrel and the gas block is not very tight, but the carbon is sealing up the gap anyways.
Is this normal - not really. If this is a brand new rifle straight from the factory, I will call LMT and make them sort it out.
Oil it already. Spray Break free on there. Let is be soaked and then let it sit for an hour then clean/ wipe the gun clean and use brushes on the rust areas. Then go shooting with it and the if any rust remains it will burn of. Then quickly clean and add oil and add oil also every 400 rds. Apply a lot.
Couldn't disagree more on the bolded line. If it is leaking that is an indication it isn't working properly and can affect BCG speed and buffer efficiency.
Is it sealed now? Maybe, maybe not.
If the carbon every dislodges or falls off during bad weather or any other type of outside influences the rifle will suffer. The gas system on a direct impingement rifle is its life blood and if it requires attention it is prudent to follow through. Don't ignore the warning signs.
You want to use locktite, Which may block the port. The gas block should have been pinned on the bottom that would created a better seal to the barrel. Appears that they didn't insure it was butted against the step down on the barrel before they drilled for the pin. Like GT said called LMT because its not normal esp for a high end AR15. Ive never seen any of my AR15's or issued C7s leak that bad.
Ar180shooter
CGN Ultra frequent flyer
- Location
- Ottawa, ON
If you car is leaking rad antifreeze would you leave it alone? hopefully not because the manufactures cooling system pressure will never be maintained leading to inefficiency. Just because the carbon has temporally sealed up the gap it is still hiding the issue. No firearm should be left alone after observing any warning signs.
I can guarantee you if it has a perfect seal it "May not" -will not impact functionality. Case in point is far too many builders worry about a gas tube restriction before they even consider the seal or even the alignment between the gas port to gas block. The gas block to barrel is the primary source of pressure to the BCG GK that needs to be taken seriously.
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Your argument is full of holes. A leaking radiator will eventually result in overheated engine. A leaking gas block will eventually correct itself and as long as the rifle functions is entirely irrelevant. Its kind of like having a small hole in the exhaust pipe. Noisy and maybe slightly annoying but has no detrimental effect on the engine's performance.
As long as the rifle functions properly, which apparently it does due to the amount of carbon present, then the OP should leave it the hell alone. Removing and cleaning etc that gas block will have no benefits.
The AR gas system is not about efficiency. In fact it takes in a lot more gas than it needs or uses. Hence the mechanism by which the gas intake is cut off as the bolt carrier moves and then allows excess gases to be vented out the side of the carrier. A bit of leakage upstream will cause no problems.
No not at all. A finely crafted Ferrari engine has machined surfaces that eliminates the need of any gasket or sealers, however a GM product requires gaskets and a sealer. A high end rifles gas block and gas port areas are precisely machined creating a perfect seal and a so so brand requires more attention that may need a sealer.
I had a similar issue that was repaired by removing the lower quality gas block and replaced with a clamp on JP SS item. The preferred method is to permanently repair the contact surfaces but, if an owner has limited resources the gun builders method of a "green" Loctite solution is fine. The point is fix it.
I respectfully disagree as the Gas System must be about efficiency. It is the first thing any OEM builder and Home Builder should take into account so the rest of the rifle can be adjusted accordingly. This carbon filled gap is akin to having a misaligned gas key that has been sealed by carbon. Yes it may work now but who knows when the carbon will dislodge and open up the matting surfaces possibly leading to malfunctions.
A perfectly balanced buffer system and BCG can only happen if the rifle is not over gassed or under gassed. Hell a carbon build-up can be a sign of a misaligned port or even over gassing.
Again an investigation is required and a remedy implemented.
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I don't need to know more than LMT but I can assure you that if there is that much leaking by something is amiss. You don't need to be a rocket scientist to see that something is out of alignment. Hell if that is how all of their products are I would never deal with them.
The upper is a used one. I doubt he's covered under any warranty. Yeah, it'll probably run fine after a good cleaning (see orig pics) and the problem isn't as bad as we're making it out to be.
Some folks can live with the "good enough" mentality but personally speaking, if that was my money tied up in that upper, I'd want to know why it's rusting, how much rust is between the block and barrel, any rusting in/around the gas port and how can I clean it up and make it better than "good enough".
Just because it's an LMT doesn't mean they can't make bad design decisions/oopsies.
Some folks can live with the "good enough" mentality but personally speaking, if that was my money tied up in that upper, I'd want to know why it's rusting, how much rust is between the block and barrel, any rusting in/around the gas port and how can I clean it up and make it better than "good enough".
Just because it's an LMT doesn't mean they can't make bad design decisions/oopsies.
