Put some pictures of your rifle out there. Up load to IMGUR, copy the BBcode, paste them so we can see the thing.
Kimber Oregon was going bankrupt, and managed to go bankrupt. I would not trust a single of their small ring 308 conversions, they are not appropriate for 308 cartridge conversions as the 308 Win operates above the proof pressures of the original action. Companies in financial stress will shovel out junk, knowing that if they fail tomorrow, the liability is gone.
As for your 6.5 X 55 conversion, keep that within Swedish service rifle loads and you should not have any issues what so ever. Basically the pre WW1 Mausers, be they small ring or large ring, were firing the same cartridge and were tested and proofed at the same pressures. Early Mausers are all made of the same inferior plain carbon steels of the era, all built in the same pre vacuum tube era factories, and thus, small ring or large ring, are not to be used with loads greater in pressure than period service loads. Small ring Mausers earned a very bad reputation with the Spanish small ring Mausers, if all large ring Mausers were as poorly built as Spanish small ring, large ring Mausers would also have a bad reputation.
If your large ring Mauser was a 1930's or 1940's or even better, a 1950's build, it could take a little more pressure, simply due to improved metal cleanliness and improved process controls, but it is only a couple of thousand psia, not tens of thousands. The steels were not changed, nor was the design.
Now, if you reload, stick to Swedish service rifle equivalent loads. My load, posted below, is a 140 grain bullet with 43.0 grs IMR4350/AA4350. As far back as the 1950's American Rifleman, this was being described as 6.5 Service rifle equivalent in terms of pressure. Velocity wise, it is not bad out of my 22" sporter barrels and it shoots accurately.