What's going on in my 870 barrel?

[Mauser48]

I bought this barrel new back in 2018. It is a remington barrel. Far from the glory years of remington. After shooting on Saturday I took it apart to clean yesterday and noticed all these vertical scoring marks inside. I can't remember if it had these marks from the factory. I have no idea what i could've done to cause these marks. You can feel these marks inside with your finger. Does anyone else have an 870 barrel from around this time frame? I don't know if this is just bad remington quality or if I messed it up, wish I could remember what it looked like new. It's an 18.5" barrel with improved cylinder fixed choke.

[Hannibal]

Picture quality makes it difficult to see any detail. Are you certain it's not corrosion damage?

[Mauser48]

Picture quality makes it difficult to see any detail. Are you certain it's not corrosion damage?

I don't believe it is. It's vertical scoring and not so much pitting and rust. There is no corrosion on the outside of the barrel.

[Winger Ed.]

What did look like after a good scrubbing & cleaning?

That will determine if the marks are 'on it' or 'in it'.

[Mauser48]

What did look like after a good scrubbing & cleaning?

That will determine if the marks are 'on it' or 'in it'.

This was after cleaning it.

[G W Wade]

Have you ever shot steel shot? I have seen vertical lines down my barrel but they have always scrubbed out. GW

[Mauser48]

Have you ever shot steel shot? I have seen vertical lines down my barrel but they have always scrubbed out. GW

I've shot a little bit of steel shot. I can try a harder solvent and see if it comes out.

[stubshaft]

How about trying Kroil and JB bore paste to see if it is some type of fouling.

[Mauser48]

I'll mess with cleaning it some more. I just used m pro 7 and clp. I have some butchs bore shine I can try. Maybe some chore boy too.

[BK7saum]

Not sure how aggressive you were with cleaning
Sometimes plastic fouling is a bear to get out of the barrel.

[Minerat]

Most likely wad streaking. I get it with some of the steel shot cups when using Large shot size goose loads. I use Shooters Choice - shotgun and choke tube cleaner and a brass brush to scrub the plastic out. I give it a good wetting, short soak then scrub.

[Hannibal]

If you think it's plastic from wads acetone will desolve it in a flash.

[Mauser48]

If you think it's plastic from wads acetone will desolve it in a flash.

That's a good idea. I shot a bit of steel through it shortly after I got it and don't believe I cleaned it after. I shot some of my lyman slugs Saturday too which fit pretty tight in the wad. Those could've contributed.

[Moleman-]

Heavyshot in their old reloading data said the rough and irregular shapes could do that mostly in the choke tubes. I've been using and reloading heavyshot cartridges for 20 years without any damage I've noticed, so I'd be inclined to think plastic fouling and give it a good scrub.

[BLAHUT]

Looks like wad residue, after steel shot, I use boreteck eliminator, takes it right out.

[725]

Probably wad residue. Ed's Red is another good cleaner for plastic left in the barrel.

[Mauser48]

Some butchs and acetone cleaned it out! I was worried I ruined the barrel and had no idea why. Thanks for the suggestions. I've never had hard fouling like this in my shotguns.

[Gtek]

Love the Ed's red and cleans mine right up after a box or two. Also pushing some fine Scotchbrite chamber out on some new to me barrel never hurt a thing.

[jsizemore]

Claybuster wads do that more than other brands for me. +1 on the acetone. Oil the blued surfaces real good after using it.

[fivegunner]

also take a bit of steel wool on a 12ga bore brush and use you drill motor, makes a clean bore every time.