Black marks on bolt/ how to remove?


January 16, 2012, 02:16 PM
I have these black marks all over my yugo m48 bolt. They keep appearing and my bore cleaner or quick scrub III can't seen to remove them. What are these black spots and how do I get rid of them?

Also, after shooting some ammo, the end of my bore (action end I mean) seems to have striations or scratch marks in it that don't seem to go away. It was shiny when I bought it but after shooting it 3 times and having gone through about 150 rounds total, I get these marks. Are the marks bad? Possibly rust from shootign corrosive ammo? ( I cleaned properly with water and what not afterwards). Or is it something I don't even need to work about for it's normal ware and tear? Thanks!

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January 16, 2012, 02:44 PM
This is a case where clear photos would really help.

January 16, 2012, 05:47 PM
unfortunately I cannot get pictures of the barrel. Those just look like scratches towards the receiver end of the bore. But here are some pictures of my bolt. Keep in mind it was shiny when I first got it and after shooting it twice and cleaning it twice, it looks like this. Is it just tarnish?

best I could do with my phone : /

Rail Driver
January 16, 2012, 06:07 PM
Looks like carbon from shooting to me. I doubt there's any problem, especially since you clean taking into consideration the corrosive ammo. I wouldn't worry about it too much. Lube and shoot.

January 16, 2012, 06:16 PM
Excellent. Thank you! Now if I did want to get that carbon off, what would you recommend I do? Also (might sound stupid) would you recommend putting bore cleaner on it and scrubbing it for regular maintenance purposes? I'm kind of new to all this 'gun' stuff ha. Thanks!

Rail Driver
January 16, 2012, 07:23 PM
You can polish it off with Flitz or a similar polishing compound, or you can polish it off using steel wool and oil.

There are quite a few things you can do to prevent this in the future, but it's normal and won't hurt anything. It may help to polish your bolt to a mirror shine (polish using sandpaper up to or beyond 1000 or 1200 grit sandpaper, using oil) if you don't want to put an aftermarket finish on the bolt.

Either way, keep it oiled and you shouldn't have problems.

Edit to add: If you decide to polish the bolt, MAKE SURE you don't change any angles, and don't sand the corners or edges down. You don't want to take off a lot of metal, just smooth out the tool marks.

January 16, 2012, 09:50 PM
Two thoughts -
1) Stop shooting corrosive ammo. There's plenty of non corrosive available.
2) Do NOT mess with the rear face of the locking lugs. You do not want to affect headspace by removing material from there.

January 16, 2012, 11:57 PM
Yeah I don't think I want to sand; the toolmarks are the least of my worries. I just want the black spots gone. Yeah I shoot corrosive ammo partially due to how cheap it is. Actually I only shoot corrosive for the cheapness. I don't want to pay $1 per round : / . What I don't understand is how all those marks get on there from the corrosive ammo. I wasn't aware primer residue reached back that far, honestly. Is it from the gas discharge? Is that how it stretches so far back? I could tell it getting blacker as I was shooting it

January 17, 2012, 12:26 AM
Yes, it's from corrosive ammo. There is no such thing as a perfect seal, some gas will come back toward you. If you're going to shoot corrosive, it must be cleaned every time you shoot with hot, soapy water, followed by normal cleaning procedures, followed by oiling.

Corrosive ammo isn't so cheap when you add in the increased maintenance requirements. If you don't want to pay $1/round, start reloading.

January 17, 2012, 12:11 PM
well here's the thing: I've cleaned all the parts with hot soapy water after every time I shot the corrosive ammo. On top of that, I've oiled the bolt ridiculously after every time with smith and wesson's lubricant

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