It vexs me that people seem intent on putting .308's, .243's, and 7mm08's on Model 98 actions.
Those are some of the most poorly suited cartridges for Mauser actions.
The following cartridges are of a length to feed smoothly without modification in most military Model 98 actions:
6mm Remington, .257 Roberts, 6.5x55, 6.5x57, 7x57, 300 Savage, 8x57
The following will feed well but may need to have the magazine box lengthened to hold the longest cartridges, and the feed ramp will also need modification if you lengthen the box:
.25-06, 6.5-06, .270 Winchester, .280 Remington, .30-06, .338-06, .35 Whelen.
These cartridges will most likely require blocking the magazine, modifying the follower, changing the feed rail geometry to feed at all, and then the feeding may not be smooth:
.250-3000, .243 Winchester, .260 Remington, 7mm08, .308 Winchester, .358 Winchester.
Basically, I try to steer people away from the .308 family in Mausers.
Clemson