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View Full Version : Did mapp gas runin my barrel ?


Matchman
September 27, 2001, 17:06
I now have a blistered (best way I can describe it) area in my barel (I removed a muzzle device).
Feals slightly rough with a patch. (It goes good with the burr I put in it yesterday drilling the gas hole larger!)

floatingFAL
September 27, 2001, 21:29
Been there,done that.And I'll bet others
have too they're just not admitting it. Heating the barrel too much lifts the chrome
(I assume it's a chrome bore).Mine didn't
blister but got very rough,after wearing out a bore brush it was much smoother to the eye
but when I shot the muzzle brake off(solder
didn't take)I was able to get my lens in there.Very rough,full of crazing and pock
marks.Clip off a couple of inchs and make a
carbine.The gas port burr should shoot away,
mine have anyway.
Ryan

msnyder
September 27, 2001, 22:09
I was reading on Crufflers.com that they are
using heat stop paste when soldering the muzzle brake.

FN74
September 27, 2001, 23:32
Don't solder. Heat can affect the treatment of the barrel, and hence accuracy. Thread and blind pin instead. Much better than solder. :cool:

Matchman
September 28, 2001, 05:18
Thanks everyone.

BBBBill
September 28, 2001, 08:23
An old Swnson/Novak trick to avoid de-carbonizing the barrel metal (the rough area)is to drive a wooden dowel into the bore for a few inches. Doesn't need to be real tight, just a hand press fit. When you solder, the wood will burn, releasing carbon, instead of the steel. I do this as well as using heat control paste, depending on whatjob I am doing.

W.E.G.
September 28, 2001, 08:43
Heat-stop paste only keeps the heat from travelling to other areas. It does not keep the area you are heating from getting hot.

I wonder whether the metal that was "lifted" was actually fouling as opposed to chrome. If the area looks better after running a bore brush through it, what does that tell you?

If the chrome were susceptible to peeling from high heat, I would think that the area just forward of the chamber would be toast on most chromed barrels in very short order.