The Mossberg I ordered finally came in today!  (590A1 20", speedfeed stock, ghost rings)

It was coated with some kind of gun gunk so I cleaned it off.  The problem is I cannot get the bore even close to clean - same with the magazine tube.  I tried Hoppes #9, Gunscrubber, CLP, scrubbed with a wire brush.... I don't know what else to try.

Any ideas?
Thanks

If a wire brush won't get it out, I am not sure what will?

I avoid wire brushes as much as possible.  

Have you tried the following?

I have a 36 inch 1/2 to 5/8 inch wooden dowl, one end I carved an eye, and on the other I trimmed to fit in my cordless drill.  I put cotton rags through the eye, swabb it up with Remington Bore Cleaner and slowly run it up and down the barrel or barrels.  It scrubs the plastic and lead deposits left by slug stuff out.  

This is what I do after shooting several boxes of slugs, or 3-400 rounds through my trap gun at a sitting, I think it does a pretty fast and thorogh job.  After the Remington bore cleaner, I do the regular Hoppes #9, clean all that junk out and oil/grease up the action and barrel for storage.  

Edited, I gave the wrong size of dowls that I use, 3/8s is too small for a 12ga, and won't stand up to repeated drill cleaning.  

Try using shooter's Choice. We used on my friend's shotgun, an old Remington left to him by his grandfather, and it cleaned it up nicely. You just have to let it sit and work in for about 15-20 minutes. Run a bronze bore brush through it,, then a couple of dry patches, and repeat if need be. It works every time for me.

OT but where'd you order your 590A1 from? I'm shopping around for one now.

Quoted: OT but where'd you order your 590A1 from? I'm shopping around for one now.

Best price I found was KY Imports.  I have heard mixed reviews about them but decided to try them anyway.  No problems other than they called and asked for more money for shipping.  I'm in Alaska, and used to that so I let it go.  They were still the cheapest even with the added shipping costs ($30.00 total).

I might have to go buy a dowel and some shooter's choice today...  I don't know if this stuff is cosmoline or what but is it stubborn as hell...

To get heavy lead and plastic deposits out, I use 0000 steel wool.  After every barrel cleaning, I also use Simichrome metal polish on a cleaning patch over a mop. I have done this for many years to clean o/u shotguns and have never had any problems.

I have a Moosberg 500. If it needs a cleaning this is what I do:
Soak the barrel with Remington Bore Cleaner and then let it sit for a while.
Next I take a bronze Tornado style brush, mount it on the end of my 12 volt cordless drill and run it out the barrel, breech to muzzle.
Blast it out with Gun Scrubber, repeat if required.
Then I'll run a jag/patch cloth down coated in Hoppes #9, if it comes back clean and there is no plastic wadding left in the barrel then it gets a coating of CLP.

When you're ready to patch it clean, use an old trick I learned 30 years ago.  Get some Tampex, open one up, and push it through the bore with a bore rod.  It fits just perfect and cleans it out just fine.

You have to clean shotguns? I have never done anything more than run a patch down the barrel of mine, it's not going to explode is it?

Try Kroil.  Midway and Brownell's carry it.
Mfg. is Kano Labs and they've a website.  Lot cheaper in bulk.  Brownell's also has a plastic wad cleaner liquid.

Works good.  Competition guys might know the formula to mix it with Ford carb cleaner for a super job.  If I can find formula I'll add it on here.

I believe it's called a tiko-tool (sp?)

It's a synthetic fiber wrapped rod that uses friction to remove the bore deposits.  I shoot a bit of sporting clays, and it's what most of the guys I know use.  You can also use it to clean your magazine tube.

Bore Snake.........

Another vote for bore snake

Just shoot the gun clean!

It's self cleaning!