Remington bolt actions are chambered for the .223 cartridge not the 5.56mm. If you are using milspec cartridges this may be the source of the problem. The chamber specifications are different. .223 rifle ammunition can be used in the long throated 5.56mm chambers but not the other way around.

See:

http://cheaperthandirt.com/blog/?p=35447

Last edited by RMcL; 05/26/13 07:17 AM.