Posting a pic or two will help.
If you could also provide a few details on the configuration and ammunition used, it will give us an idea of what you are working with. Specifically could you tell us details like the brand of lower receiver, caliber, barrel length, gas tube length, if using a gas block is it screwed down or pinned and it is factory installed, buffer weight type and buffer spring used, magazines types used,, have you cleaned it and lubricated the 7 bolt lugs so they are good and wet, amount of rounds fired through it so far, types of ammunition used (Factory brand, home loads, bullet type and weight), etc.
The problem you are experiencing may be one simple thing, or a combination of things, so any details you can provide will help us know what you have and possibly how to fix it.
CY6
Greg Sullivan "Sully"
SLR15 Rifles DefensiveEdge.com(763) 712-0123