Good advice and I do have extra mags, but I didn't want to dispose of a freshly re-blued mag (it was done with the rifle).
This morning I pulled out a mag spring from a 98 mauser. It looked identical to the remington mag. So I gave it a whirl and it fit 100% without any modification to the spring. So, I guess I'll be on the lookout for a 98 spring. Should be easy to find one.
Cheers,
Rich