I have quite a few packs of Federal 215 and Winchester magnum primers. Can I use these in a 270? Any drawbacks to using this combo? Thanks in advance.

Yes, you can. Use the the normal starting procedure at a lower powder charge and work up. Like always, watch for sticky bolt lift and hard case extraction - assuming you are using a bolt action. If not just watch for anything out of the norm compared to previous loads.
Years ago, I used nothing but Federal 215 primers in my 270 and 22-250.
I honestly couldn't tell any difference between those and non-magnum primers in any of my bolt action rifles. I still shoot some ammo loaded up with Winchester LR Mag. and Fed. 215 primers on occasion. Works fine.
Just "work up" the load.

I appreciate the response. Thank you

If you hunt in very cold weather with ball powders your are probably doing yourself a favor with magnum primers.

I only use Magnum Primers in my .270Win. The Fed215 are renown for low standard deviation and accurate groupings. Never had any misfires on the Federal Primers.