I have noticed that I have silver metallic flakes in the the receiver when I clean my rifle when coming back from the range. I dont recall seeing any in there when I was using federal ammo but there seems to be a small amount now that I am using remington corelokt. I checked on the internet for some anwers with little luck so I figured I would check here.
Any ideas as to what this is?

Sbo,
The only places where metallic flakes could be coming from are the magazine follower or the Bolt Body if it is chrome plated (Flakes would look chrome) and the Bolt Face! If the Bolt Face has a rough surface, it will shear off flakes of brass from the Cartridge head when the round is chambered. Check the bottom of the Bolt Body, Magazine follower and the Bolt Face.

Also, are you shooting nickel plated brass?

I have seen brass flakes from the brass before.

It looks as though the bolt scrapes the cartridge when I chamber and eject a round.

Yep, that would be my guess also.

The magazines can sometimes scratch them also. When feeding in and out.

OK I checked something out, my rifle does not have a magazine, it is only 6 months old and has only had about 200 rds through it. It holds 5+1 and when I load it that way or with just 5 rounds what happens is the tip of the fifth bullet scrapes as I chamber the round. As I cycle through the fourth round through the last round do not scrape. if I load 3-4 rounds this does not happen. As I mentioned earlier I dont recall this happening when I used federal ammo I dont think this will effect anything as I have yet to find any of these flakes in the barrel but I am just a novice so any suggestion or comments are welcome. I figure my options are: live with it, dont load five rounds, change ammo and see if it continues (hate to do that since I really like how well corelokt shoots in my rifle; dead center of bullseye on first shot at 100yds every time.), take it to a weartherby gunsmith (covered by warranty?) and let him repair it with the closest one being in Hunstvile.

I have a win model 70 270 that will hold 5+1. I have never liked to load 5 in mag as it just seems like it puts alot of pressure on the spring. I have never had a time that I unloaded that many shots at once, so it has not been an issue with me.

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"I really like how well corelokt shoots in my rifle; dead center of bullseye on first shot at 100yds every time."

Ditto on the coreloks

The extractor on the Rem 700 will sometimes remove the sharp edge corner off of a cartridge rim when the bolt is opened and a cartridge is extracted.

Unlike the Sako type extractor, which uses a claw to grab the rim, the 700 extractor is the circular spring steel thingy/doo-dad under the rim of the boltface, held in place by a teeny-tiny rivet.

When the bolt is closed the extractor expands slightly to fit the case rim and grips it in the groove between the case rim and the case body. When the bolt is opened and is pulled back, the ejector spring pushes the case to the right, and the extractor springs open slightly allowing the case to pop out and sometimes removes with it the sharp corner edge of a case rim.

These small sliver shavings of brass usually fall down in the magazine. Some find their way behind the action lugs over time and must be cleaned out occasionally with the proper tool.

If you use a light bolt grease on the bolt lugs as you should, the grease holds these tiny shavings and sometimes causes the bolt to close harder than necessary.