I purchased a Remington 700 chambered in 300 win mag in September. The rifle was brand new in the box and still in the box up till yesterday. After installing a new safe I was transferring my firearms into it and happen to catch a glimpse of the bore. To my surprise and shock there appeared to be rust. I immediately ran a patch of Hoppes # 9 up the barrel and noticed a blue color over the patch. I am assuming the blue is copper fouling reacting with the Hoppes #9. I than ran a bore brush and some Bore Scrubber followed by more patches that came out covered in blue. At that point the bore was pretty clean and I can see it’s not rust but copper fouling.  Would this be normal from the factory? I know rifles are test fired but would that leave so much copper fouling?

It's almost always there

The bore could also be rough and could have held onto more then the usual amount of copper from the test firing. However, nearly every factory rifle I've seen has had dirty bores. In this day and age you'd think they'd run a boresnake through it or something.

When manufacturers try to cut costs they tend to use drill bits and rifling cutters that are beyond where they should be replaced, and you end up with rough bores and chatter marks on the rifling.  That results in more copper fouling than normal.  I had a Marlin that was really bad (you could SEE the chatter marks in the rifling) and it scraped lots of copper off the bullets as they passed through.  It still shot really accurate, it just looked bad.

 

It's not a big deal.  If you want to smooth things out, you can use some JB Bore Paste or just shoot it and clean it and repeat for decades, it will eventually smooth out through wear.

When manufacturers try to cut costs they tend to use drill bits and rifling cutters that are beyond where they should be replaced, and you end up with rough bores and chatter marks on the rifling.  That results in more copper fouling than normal.  I had a Marlin that was really bad (you could SEE the chatter marks in the rifling) and it scraped lots of copper off the bullets as they passed through.  It still shot really accurate, it just looked bad.

 

It's not a big deal.  If you want to smooth things out, you can use some JB Bore Paste or just shoot it and clean it and repeat for decades, it will eventually smooth out through wear.

 

 

I can see chatter marks on the rifling, they are pretty rough looking.

What do you recommend using to remove copper fouling?

1) It is a really good idea to really check a rifle very well before you take delivery. I wouldn't have bough it.

 

2) The traditional way is an ammonia based cleaner like Sweets 7.62. The other thing that works really well its the foam based bore cleaners, spray in the bore, walk away for 30 min, mop it out.

Hoppe's copper solvent..  

Hoppes M-Pro 7 Copper Remover works good too, and doesn't smell.  Uses a different chemical reaction than ammonia.

 

I'd get both that and an ammonia type cleaner and use both.

 

Apply, let it soak in 15 minutes, wipe out, repeat.....

KG-12 works best for me. Non-ammonia formula and works fast and amazingly well.