The 1903 Springfield does not work well for DST because of the small triggerguard. The typical German solution was to use a shotgun triggerguard to accommodate them. Occasionally you will see a triggerguard that has been lengthen. I don’t remember who sent me these photos, if this is your rifle let me know.

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Not my rifle but the way the trigger guard was lengthened is interesting. I have a sporter built on a Romanian M93 action that was a bring back from WW2. It is fitted with DST and the original military trigger guard was lengthened the same way with the separate interlocking piece to the rear to accomodate them. This one forming a shotgun guard w/tang piece down the grip.
Don't know if the pics show it or not.