M4 Mag tube removal damage

[Skull and Bones]

OK, worried about the heat gun damaging the finish on the receiver. My gun doesn't have a temp setting. Any tips or tricks to help guys?

 

Thanks! 

[Sukhoi_fan]

You know you've hit the right temperature when it starts "smoking like a chimney."

j/k

If you keep steady on both the heat and your twisting pressure (torque) on the magazine tube to get the magazine tube to break out it will break out long before you damage the finish.

Wisps of smoke from the thread locker is a good indication you are approaching break out so when you reach that point you begin to take more care on the heat (but don't back off the heat yet) and apply more torque to the mag tube. Once you get it to break out then cut the heat and concentrate on unscrewing the mag tube.

[StrangerDanger]

Focus the heat on the magazine tube you're removing. Very little of the heat will wick into the receiver. The old tube isn't worth anything anyway.

A heatgun isn't going to discolor much.

[RPC]

YMMV, but a couple of months ago I changed the original mag tube on my six-month old M4. It needed maybe 30 seconds of medium heat from a new DeWalt heat gun. Could have “needed” even less than that, potentially even none(?).

My point: If your M4 is within a year old, your experience might be like mine and need nearly no heat to break the original mag tube free. 
 

Best of luck. 

[Scout_21]

I used a blow torch by inserting it in the area that would normally be occupied by the lifter and heating up the inside of the magazine tube where it is threaded into the receiver.  It took a bit to position everything.  I heated it up in "pulses" to not over heat one area but once it started smoking, like Sukhoi said whisps, I was able to unscrew the tube.  No discoloration or damage to the receiver in my case.

[SVT]

What RPC says. I got my gun earlier this year and the mag tube came right off too, within a minute or two of heating it with a DeWalt gun. Whatever factory locktite there was, it came off with the old mag tube threads and not even any residual remained on the receiver threads. Couldn't have been easier

Edited December 7, 2019 by SVT

[Jolly Roger]

Like Scout_21, I also used a torch. Ive done six of them now. I take an old wash cloth and soak it and lay it over the receiver before I heat the tube. The Loc-Tite WILL start to smoke a bit. Never had one come loose before it started to smoke.