Is this normal?

urge · July 5, 2012, 08:45 PM

I was at the range today with my AR15 doing double taps, went through 60rds in about 10 minutes, and i noticed white circles appear around my barrel. Dont know if these are cracks in the barrel or just from the heat.

http://i1101.photobucket.com/albums/...705_191813.jpg

10-96 · July 5, 2012, 10:23 PM

That looks like results of heat and whatever handsweat, cleaner, or some other chemical that was left on the bbl. Anyhow, it does not look at all serious.

NESHOOTER · July 5, 2012, 10:49 PM

I also do not think the barrel is harmed but it does look like a trace of something left behind for either water or think cleaning substance.... your right on 10-96.

urge · July 5, 2012, 10:53 PM

Thanks for the replies, seeing that the barrel is a pretty important part of a firearm (lol) i just wanted others opinions on the matter. I own many guns but have never had that happen before so i was just curious, thanks again

10-96 · July 6, 2012, 12:11 AM

Quote:

the barrel is a pretty important part of a firearm

It's all really subjective and relative to your point of view. If you were to remove the barrels from your firearms, think of all the money for ammo you'll save. You'll also save wear and tear on all the other parts as well, and well- the barrels themselves will likely never wear out. Of course the fallbacks are you'll experience much less fun and personal enjoyment, may develop fits, and possible bouts of severe constipation if one does not shoot on a regular basis.

gyvel · July 6, 2012, 02:23 AM

If you are worried about potential cracks, just get a can of spray penetrant to check. (Any good aircraft mechanic can tell you where to get it.)

It's not inconceivable that you have hairline crack forming from crystallization of the metal.

James K · July 6, 2012, 02:38 PM

If those were cracks, I think you would have found out for sure by this time.

Jim

mehavey · July 6, 2012, 04:14 PM

Barring some really weird manufacturing defect,when a cylinder (i.e., a rifle barrel) fails
from pressure, it splits lengthwise. (think hotdog)

I wager the white bands are the effect of high heat on areas where cooling oil from barrel
shaping/lathe work was not "completely" removed before Parkerizing.

madcratebuilder · July 7, 2012, 07:33 AM

Quote:

Originally Posted by James K

If those were cracks, I think you would have found out for sure by this time.

+1000

The barrel is fine. You are seeing the remains of fluids the have heat evaporated off the barrel surface. They well disappear when you oil the parkerized surface. You well see similar marking the next time you get the barrel that hot.

I treat parkerized metal with Eezox, it leaves a non-oily feel with a nice even color. Best protection available.

Quote:

Originally Posted by mehavey

I wager the white bands are the effect of high heat on areas where cooling oil from barrel
shaping/lathe work was not "completely" removed before Parkerizing.

This could very well be also. If you see the same marking appear the next time you get the barrel hot it is probably a defect in the Parker Rust Proofing.

July 5, 2012, 08:45 PM	#1
urge Junior Member Join Date: July 5, 2012 Posts: 7	Is this normal? I was at the range today with my AR15 doing double taps, went through 60rds in about 10 minutes, and i noticed white circles appear around my barrel. Dont know if these are cracks in the barrel or just from the heat. http://i1101.photobucket.com/albums/...705_191813.jpg

July 5, 2012, 10:23 PM	#2
10-96 Senior Member Join Date: October 19, 2005 Location: Tx Panhandle Territory Posts: 4,159	That looks like results of heat and whatever handsweat, cleaner, or some other chemical that was left on the bbl. Anyhow, it does not look at all serious. __________________ Rednecks... Keeping the woods critter-free since March 2, 1836. (TX Independence Day) I suspect a thing or two... because I've seen a thing or two.

July 5, 2012, 10:49 PM	#3
NESHOOTER Senior Member Join Date: October 16, 2009 Posts: 517	I also do not think the barrel is harmed but it does look like a trace of something left behind for either water or think cleaning substance.... your right on 10-96.

July 5, 2012, 10:53 PM	#4
urge Junior Member Join Date: July 5, 2012 Posts: 7	Thanks for the replies, seeing that the barrel is a pretty important part of a firearm (lol) i just wanted others opinions on the matter. I own many guns but have never had that happen before so i was just curious, thanks again

July 6, 2012, 02:23 AM	#6
gyvel Senior Member Join Date: August 30, 2009 Location: Northern AZ Posts: 7,172	If you are worried about potential cracks, just get a can of spray penetrant to check. (Any good aircraft mechanic can tell you where to get it.) It's not inconceivable that you have hairline crack forming from crystallization of the metal.

July 6, 2012, 02:38 PM	#7
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	If those were cracks, I think you would have found out for sure by this time. Jim

July 6, 2012, 04:14 PM	#8
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 6,883	Barring some really weird manufacturing defect,when a cylinder (i.e., a rifle barrel) fails from pressure, it splits lengthwise. (think hotdog) I wager the white bands are the effect of high heat on areas where cooling oil from barrel shaping/lathe work was not "completely" removed before Parkerizing.