Sig 556 vs 522 - Samson STAR Sig 522 Rail System

Do not purchase if you intend to install this kit on a Sig 556 rifle. I purchased this rail kit based upon another review here stating that it could mounted on a Sig556. This is incorrect. In order to mount correctly on a Sig556, a notch would be required in the inner-rear portion of the upper rail piece to account for a tooth on the upper-rear portion of the gas tube (meant for mounting a factory plastic handguard). Apart from the issue of incompatibility, the handguard has an even parkerization, with rails marked for each mounting postion. The build and quality appears to be about on par with that of my factory Swiss SG551 and 533 rail kits. This kit will utilize the bayonet lug when mounting, so be ready to remove the lug and roll pin if you have a one installed. All mounting hardware was included and instructions included were clear (up until the discovery of incompatibility).