northernbill,
You never burn your bridges at Remington, as they must support their product. I believe they have looked over the rifle and can find no fault because of your persistence. Kudos to you. Now for the possible problem with a little history.
27 years ago I took an NRA excellent condition early issue Remington 760 in trade (for $80). I never liked the rattle or movement of the fore stock, but it was a very accurate rifle (about 1 MOA as long as the barrel did not get hot, at which point it shifted right and up 4 inches and opened to about 3 MOA at 100 yards)). However, I had to buy three magazines for the rifle. The one that came with the rifle was no good (admitted by the fellow that traded), a second, new magazine, did exactly what you are experiencing. The third magazine was the charm. I have also owned three Remington semi-autos, and noticed exactly what rickt300 commented on; rest the rifle using the magazine as the point of rest and this does happen, whether offhand or on the bench. I do not like the Remington magazines and have had them exhibit very erratic performance characteristics, even when new. I've had some that only function as three shot capacity devices. These were all Remington, not after market. Thus I offer this suggestion: try one more magazine; obtain it directly from Remington to insure it is not a factory second being distributed outside the first tier distribution system or a rework repackaged as new. Please keep us posted.
