I used either a Leupold 1.5x5, or a Beeman SS-3 1.5x4, which was my favorite, both on a ARMS claw mount.
The Beeman was my favorite. For its size, its one hell of a scope. It was small enough that both it and the claw mount would fit in a field jacket, or BDU pocket without any troubles.
This is the Beeman on my MP5. It was mounted more centered on the mount for the 91's. The mounting locations on the receiver are different, with the MP5's being more forward.
Using the ARMS mount with either scope, I never had any issue with getting a good, natural cheek weld with the fixed A2 stock. All you have to do is just move your head up the little ramp slightly to get a proper weld.
For me, the German mounts put the scope way to high, and to far to the rear for comfortable, natural shooting. It must be a German thing, as all their mounts seem to be set up this way. The ARMS mount gives you a lot more versatility in how and what you mount. Its also about half of what a commercial HK mount costs.
Eye relief for me, is with the scope right over the rear sight. Its the same with things like the AR, and a few others. It helps keep things the same as far as shouldering and cheek weld.
How are the 91s for accuracy with good reloads?
I've heard that these rifles "eat brass" or are hard on the casings, during ejection.
Accuracy with both of mine equaled or exceeded my standard M1A's, shooting both GI and reloads.
If you reload, you want a port buffer. It clips to the receiver at the ejection port, and keeps the brass form impacting the rear edge of the port and deflects the brass more forward.
With a buffer, brass is easily reloaded. I usually only got around 6 reloads from the 91's though, compared to around 10 for the M1A's (assuming the case mouths held up). I think its just the nature of the best with the 91's system.
Contrary to what you often hear, the flutes dont bother the brass, and once tumbled, the scratches left on the brass are usually barely noticeable.
The HK 90 series are great rifles. They were basically the originators of the modular systems so popular today. Their slings basically started that whole sub system. Their iron sights are the best "combat" iron sight going. Their claw mounts really started that whole sub system.
What he said.
