They cut down the weight of the rifle significantly by reducing the stock, eliminating most of the fore-end, and shortening the barrel, without reducing the muzzle energy of the round. Bad idea!
I loaded lighter bullets (150s i.o. 180s or 174s) with a reduced powder charge, and that helped some. But not much. An unpleasant rifle to shoot.
Same thing happened with the Walther PPK - which is a nice shooting gun in .32 auto, but .380 kicks like a doggone mule. I had a nice pre-68 one, but I sold it because I didn't like spraining my wrist. The modern compact .380s are designed for the round and are a pleasure to shoot.
Funny story about my (also) pre-68 PPK while I had it. For a short while I was on a Marine Corps shooting team and while I was at Camp Lejeune to compete in the Marine Corps Matches, I was assigned a Master Gunnery Sergeant to be a member of my team.
The Master Gunnery Sergeant was one of the top shooters in the Corps, which was great, but he was disdainful of officers (I was a captain back then) and he delighted in trying to embarrass me at every chance he had. For instance, one morning while I was taking my junior team members for a run - to build up their blood flow/oxygenation for the long matches - I called out to the Master Gunnery Sergeant to come run with us. He answered, nice and loud for everyone to hear him "Oh, no Sir - you go ahead and run. I learned to shoot well so I'd never have to run, but you go ahead". Of course, the troops laughed.
I couldn't stand the guy.
One afternoon during pistol practice (one hand, .45, 25 and 50 meters) he spotted my PPK and my shooting bench and said (loudly) "Of look, the Captain has a Saturday Night Special". I said, "OK, Master Guns, 25 meters, best of five round, loser buys beer"
He said "Oh Captain, I hate to take your beer but OK".
I shot the hardest I ever have and beat him with the PPK. He never bought any beer but it shut him up.