Curl,
It appears that you got a bad experience with a poor sample detachable stock Mannlicher-Schönauer rifle.
I have shot many of these rifles and I have hunted in mountain many years with a 6,5x54 1903 rifle in that quickly take apart pattern. It was scoped and delivered outstanding accuracy with the old 156 grains H-Mantel open nose RWS.
All the other Schönauer rifles with detachable stock I have tested at the range, 1903, 1905, 1910 and 1924 HV (30GVT, 7x64 or 8x60S) shot as accurately than the fixed stock ones.
I haven't fired a 1908 in that guise.
For the accuracy I think that the detachable stock system is much better than the screwed barrel and it's interesting to notice that Holland & Holland and Westley-Richards have adopted this Mannlicher system after WW1.
The trouble with hand screwed barrel is with the headspacing and it's what Holland patented their belted case.
Indeed that's only my opinion.
Best.

DORLEAC
www.dorleac-dorleac.com