Need to finish your FMP21/HK21 build?  The HK21 requires the welding of reinforcement rails into the receiver.  STS has acquired 120 HK G3 stock rails from Germany.  With a crazy and complex fixture to hold a part containing a taper and the teardrop shape, STS has modified the G3 rail to be a HK21 reinforcement rail.  These are the original tear drop shape G3 rails from the HK factory.

These are a limited quantity run, we currently do not have a firm pipeline for more of these in the future; therefore, get them while they last.  These parts are on a dedicated machine and will ship as they come off to the orders at the top of the list.  We expect to have them all completed by end of August.

Material: German Steel

Sold as a pair, right and left.

Due to the variation in the outside of the HK21 and its variants, some fitting may be required.