I've never seen this German Modell 97 action before, but have owned a number of M96's, a M93 and two M94's.
As to strength?

The M94 I now have, is chambered (by someone?) in .308 Winchester, which is a 60,000psi round. A good or bad idea, it has survived factory 180gr. ammo for 30years by the fellow I received it from.

The M94's and M96's I've had have been chambered in 7x57, ie: 57,000psi, 8x57 another 57,00psi round and the 6.5x55, a 55,000psi round.

I have seen M94 Husky's listed as M96's for sale, chambered in 8x57 - 57,000psi, 9.3x62 - 57,000psi and the .30/06, which is another 60,000psi round.

My M96 in 6.5x55 has driven 129gr. Hornady Spire Points at 2,960fps with the same maximum web expansion as factory 156gr. Norma ammo, when using once fired Norma brass in my handloads. I loaded to the same speed, same load and received the same expansion in RP brass. It also put out 140gr. Speer Spitzers at 2,860fps.

So - point being, the modell 97 must be a decently strong action, even better than the ones I listed, that is, if you put faith in the third lug and should be fine if one sticks to it's European factory ctg. pressure levels - ie: 57,000psi or less. I would not push it further than that, personally.

Kuduae - good note: "When the 9.3x62 was introduced by Otto Bock, Berlin c1905, smokeless powders were still in their infancy and produced much higher pressures than needed today to achieve the same ballistics."

Should also note than many rounds were underloaded as well, compared to what they would be today, or were later on, merely due to the instability of those early powders in climatic extremes.

It was after 1923, when the 9.3x62 was raised from 2,175fps to it's current 2,340fps (approx.)

Today, with what seems a quite moderately light load indeed, a 9.3x57 can achieve the 9.3x62's earlier factory ballistics which were what initially made the 9.3x62 famous. This speaks volumes for the 9.3x57.