You can get centerfire barrels clean. I personally am convinced you do not want to get barrels perfectly clean. Especially factory barrels. They just seem to shoot better dirty, as long as they are not real bad. I do not clean mine (even handlapped barrels) real good. I get most of the powder and copper out of it, but not all. In some guns, I do not clean at all until I notice the accuracy drops off. Some need a regular cleaning, but like I said, i do not take it down to bare steel. I had a factory Remington 700 VS in 222 and it definitely liked a dirty barrel. If I cleaned it, it would shoot bad until it got a good 100 or more rounds down the tube and then it would start shooting .25" groups all day long. I never found out how many rounds it took for it to lose accuracy. I would feel guilty about not cleaning it and scrub it up after a couple of years and have to go through the routine all over again. You will have to find out what works best for your particular rifle. If I was a betting man, I would bet that it will like a dirty barrel, being it is a factory barrel.
Here is an excerpt from the FAQ on Shilen barrel site.
How clean is clean?
We get this question many times and have a great deal of difficulty helping some customers understand that a rifle barrel does not have to be spotless to shoot great. Many times more harm than good is done in trying to get it that way. Picture a car's fender. If the fender has a small dent in it, then professional application of body putty fills the dent. When painted over, the dent becomes unnoticeable, and the surface of the fender is smooth and consistent. The same thing happens in a rifle barrel on a microscopic level. Removing this small trace of copper puts you right back to square one. The next bullet that crosses that area will, again, leave a small trace of copper. Similar to patching a pothole. All successful benchrest shooters shoot one or more "fouler" shots down the barrel before going to the record target. This is not to warm up the barrel. They are resurfacing it on the inside. Benchrest shooters clean between relays to get the powder fowling out, not the copper. However, since copper usually comes out with the powder, they know that it must be replaced to get "back in the groove". I've had shooters tell me they "cleaned their rifle for 3 hours to get all the copper out of it." Their next statement is almost invariably that they had to shoot 4-5 rounds through it just to get it back to "shooting" again. This tells me that in order for the rifle to shoot well again, they had to replace the copper they worked so diligently to remove. I have a 7x08 Improved that shoots the same 1/2" MOA after 15 minutes of cleaning or 3 hours of scrubbing and de-coppering. Personally, I prefer shooting to cleaning. The gist of this is to set a regular cleaning regimen and stay with it. If the accuracy of the rifle is acceptable with a 15 min. cleaning, why clean longer? I would much rather have people admiring the groups I shot than marveling at how clean my barrel looks on the inside.
Good Luck and Good Shooting
