I was thinking the same thing. The HK-91 was a fine rifle, extremely accurate, reliable but as you said, too heavy and also it just does not carry well. Too bulky.
The Browning or Ruger 10/22 are both fine but the 10/22 has the advantage of quick reload.
I will never understand why the 25 rd mags are so huge and long, the 10 rd box is small compact and dependable.