Adam,

I once did work on a 1903 Greek that had been partially converted to .257 Roberts.

Someone had rebarrelled it and restocked it but had done absolutely no work to get a cartridge in the magazine nor to get it to feed.

I had a later commercial MS .270 magazine available which didn't (?) have the fins between the cartridge bodies. So I removed them from the 1903 mag. I left the "cartrige pushing paddle" on the spool of course......... and the fins on the neck section (?).

Then I increased the diameter of the radius inside the magazine where the case head rotates (as the magazine is filled/emptied) to suit the new case head size and made and fitted the "wings" that support/guide the shoulder area of the case.

It was then a case to "spot" in the cartridge to fit between the feed rails of the action. Then it would allow you to feed the magazine through the top of the action and to empty the magazine when you pushed the "little button".

More "spotting" eventually allowed the cartridge to feed from the magazine into the chamber.

Eventually the thing fed just like a Mannlicher.

If my memory is hazy on this it's because it's been a while since I did this job and the alcohol that I drank to forget it must have been effective.

The things you do for mates !!!!.

If I had an original MS takeoff mount, double set triggers, a good donor rifle, along with an appropriately contoured stock I may well attempt this again........supposing I had alot of other projects done.