Looking for the cocking tube they sold either the MP5k/SP89 or the MP5/HK94 variant. Great to find one ! Thanks all.

I recently acquired an HK91 that was converted prior to my purchase to a PSG1 by IGF. My question is that the handguard feels very loose and is only attached to the cocking tube at the very front. I realize that this is because the barrel is free floated but when I removed the handguard it...