Stug,
Like Eagle27 said, PH made a 404 on their actions, they were workhorses from memory.
Would have to trim about 5mm off the back of the magazine as the 404 needs about 90mm clearance, my PH's have about the 85-86mm length magazines.
A bit of work to do, best to discuss with a gunsmith first as to cost - but are good actions to base projects on.
Cheers
93x64mm