I have a new DPMS 20" stainless varmit barrel upper that I have been breaking in. I have followed the break in procedure and noticed that I still have some copper fouling in the barrel. I can see copper in the lands and grooves at the end of the barrel. So my question is this, do I need to clean the barrel down to the steel or is some copper fouling ok? The last cleaning session, I used a brass brush and a number of patches soaked with bore solvent/copper remover and still have the above mentoned copper fouling.

Thanks......

Get yourself some Butches Bore Shine, Sweets or Tetra copper cutter. All of these work extreemly well at removing copper. Just be careful with the Sweets as it is the most powerful and can harm the barrel if left in to long.

I don't get in too much of a tissy if I see SOME fouling in the barrel.  If I notice degredation in accuracy, or it's just been a long time since I've done a thorough cleaning, I'll bust out the Sweet's and get it cleaned out.

Given yours is a new barrel, it probably wouldn't be a bad idea to get some good harsh solvent and give it a a good cleaning.  Then you'll be ready to roll!

Gundraw

P.S.  Just for your info, match shooters are known to decopper their barrels every 5 shots or so (IIRC).  Kinda a waste in my opinion.  It seems the common round count is 1-2K, then get the copper solvent out and clean it all out.

Benchrest shooters, maybe, but then there groups are less than bullet diameter on a bad day.

Ipsc, 3-gun, CMP, shooter What is this cleaning you speak of every 5 rounds.

Thanks guys, I tried Outers foam bore cleaner and it did the trick. Kinda odd, I made several passes with a brush and patches using Shooters choice but still had some fouling. This bottle of Shooters choice is very old, does it go bad?
Well as far as groups go, out of several five shot groups I will have three that can be covered with a dime or nickel, and then two that open up the group to 1.5 inches or so. I suspect the two flyers are me (50 year old eyes) or the trigger, stock trigger and it is long and heavy, gotta fix that, what do y'all recommend? This upper seems to only like 68gr Black-Hills so far, WWB 52 and 62gr work but don't group, well 1.5 inches or more,  also 52gr BH does not group. Less than 200 rounds thru it so far.
Thanks for the feedback, this is a great site.
Steve R.

If your a brush dunker any solvent will go bad.

Try using FP-10.  Put a heavy coating (with patches) in a "clean" barrel and leave it for a few days.  Then come back and brush / patch as normal with only FP-10.  I think that you will be surprised at how "clean" your barrel really is.  I was stunned the first time I tryed this.

Quoted: I don't get in too much of a tissy if I see SOME fouling in the barrel.  If I notice degredation in accuracy, or it's just been a long time since I've done a thorough cleaning, I'll bust out the Sweet's and get it cleaned out. Given yours is a new barrel, it probably wouldn't be a bad idea to get some good harsh solvent and give it a a good cleaning.  Then you'll be ready to roll! Gundraw P.S.  Just for your info, match shooters are known to decopper their barrels every 5 shots or so (IIRC).  Kinda a waste in my opinion.  It seems the common round count is 1-2K, then get the copper solvent out and clean it all out.

I didn't specify very well.  Long range/benchrest shooters are the the types of shooters I was referring to that use such practices.

Gundraw

I believe brass is an alloy of copper and zinc. So if you use a brass brush to scrub your barrel using a copper cutter (ammonia based) you will be breaking down the copper in the brush and possibly depositing copper in the barrel from the brush. Not to mention you'll shorten the service life of the brush.

I was told to use nylon brushes when using a copper cutter. It works for me.

Shabo