Shouldn't have feeding issues with the long-action, but I can't say for certain as I haven't done it on an older staggered feed. I do have a .284 Winchester in an centerfeed L/A that feeds just fine with an '06 magazine.

One thing to consider - I assume you're planning on shooting the longer VLD-type match bullets, and as such the long-action would give you more room to seat the bullets out further.