I had a gunsmith install a bolt catch and he used a towel to make sure he didn’t scratch my lower but I got this scratch out of it. He claims the punch polished the aluminum when it hit it. Has anyone seen a scratch like this? How do I get rid of it? Thanks guys!
Rub a little frog lube or oil on it
Should have used electrical tape and not a punch but a press method like vice grips.
You get rid of it by shooting it.
Just shoot it or cold blue pen.
That scratch is not even worth noticing. If one so small is a bother, perhaps My Little Pony would be a better investment than a rifle for you. :jester:
While I wouldn’t be thrilled to have paid a gunsmith for that scratch since I was able to install my bolt catch in my basement having never done it before without scratching anything, the fix really is to just shoot it. The metal slider on my sling has left more noticeable wear than that just from handling.
It’s sad that a so-called gunsmith did this. Probably didn’t use the correct tools. But, aside from the principle of the idea I would simply move on. And then I would learn how to do it yourself, so when it happens again you can blame yourself and not be pissed at him.
The fix is easy…just run the rifle like it should and you’ll probably get scratches and dings everywhere, and you won’t even notice this little scratch. 
Did he not use a roll pin starter?! It looks ok other wise. If your concerned get some gun plaster and paint over it with the corresponding black sharpie color. I have lowers with bigger scratches because I actually dropped the gun in a 3G match (very embarrassing btw).
Minor scratches on an AR just give it character.
Unless you are just going to be taking it out of the safe every once and a while to look at, its gonna get way more scratched up than that before long.
it still stinks that it happened, but most of my new lowers arrived with more cosmetic damage than that just from the carboard box.
I had to look really really close to see this scratch. I wouldn’t lose any sleep over this, like others have said … learn how to do these things in house and use the proper tools when doing so. You’re going to get a lot more scratches on that thing by the way 
It’s amazing the thing you can prevent with blue painters tape…
Nailed it.
And if that scratch bugs you…you might not ever want to take it out of the safe. Ever. It WILL get dinged, dented, scratched and grimy.
I take pride in trying to get that Roll pin in without protection. It’s amazing the care we take to put a gun together flawlessly… and then go balls out with it in the hills.
A gun is like a car. The first scratch hurts like Hell and you don’t feel any more after that.
:laugh: now that is the truth
they are ugly as hell anyway.
and meant to be used and abused
+1. The most important lesson for the OP is to find another gunsmith … preferably himself. It’s not difficult; it’s actually fun.
I use blue painters tape to protect the receiver when installing the pin. I don’t know why I bother with my own carbines, because after the first hard training evolution at the range the carbine looks like I threw it down on rocks and broken glass.
If it bothers you, pick up a Birchwood Casey pen and fill in the defect.
Focusing on your front sight post makes it invisible. 