Paint pen use on a carbine

[N2WishN]

I am starting to see more and more people use paint pens on their screws and other parts on the weapon. Can some one school me on the application of paint pens to the rifle. I see it used on the rails, the nuts, and on some qd mounts.

[mattj]

They are using the pens to make witness marks on the screws, nuts, etc so that if they start to back out over time, it will be visibly apparent and can be remedied.

It is just to help ensure that something doesn't decide to fall apart at an 'inconvenient' time.

[travistheone]

Matt, thanks for the insight, cool tip.

[TehLlama]

Quick go-nogo for if something has come loose. For my rifles, these index marks are also the indicators of whether I've shaken down those rifles and blue loctited/staked them in place.

[SWATcop556]

I use it on my screws as witness marks to show if there is any unwanted movement. I also use it on my BUIS to show where I'm zero'd at if I need to make adjustments for windy or inclement weather shooting days.

[N2WishN]

Silly question, so when u mark this rifle with pens the accessories then become weapon specific or is it easy to come off?

[bkb0000]

paint pen comes off easy just using the gun.. especially so if you use acetone/similar.

i use witness marks on all screws.. i also witness my irons for Z. i also use a nice broad stripe of silver on my selectors, for easier reference in the dark.