So I did end up purchasing this rail for the new HK SP5 (Dec 2019) release and it fits perfectly. Honestly looks a lot better than the real HK mount ever does. It's super well made and honestly I like it better than the factory HK SP5K mount. Solid build quality. This company proves you can make good products without breaking your pocket book. BUY IT!
That will really depend on how the top of the rifles receiver is machined. This clamps onto the top of the round receiver and there should be a few small square protrusions on the top portion of the receiver where the clamps latch onto to. If you look at the images you will see how the mount attaches. If you cannot confirm that it will fit please feel free to email us at techsales@opticsplanet.com with images of the HK91 and the receiver most importantly and we can hopefully verify whether this mount will latch on.
Yes. This NcSTAR MP5/HK Claw Scope Mount fits any HK MP5 and clones, and will allow you to mount an optic to your MP5.
Yes it should fit.
I would recommend emailing us at techsale@opticsplanet.com to help you further.
Yes it should fit.