don,
A magnum primer probably won't help with the 110gr load. The max for that load is because thats how much powder you can get in the case!
Your ~30fps is actually a good spread for a .270. However, I normally see the velocity you're getting with the 110gr bullet with a 130gr bullet.
I had good luck with the .270 using IMR4064 and IMR4320 with 110gr bullets back in the '70's when I was tinkering with the .270. Didn't have a chrono back then, so can't comment on velocities. According to the manuals though, they were running 3,200 to 3,300. Trajectory was about right for those velocity levels.
Ditto, what others said about magnum primers. I've mostly used the Winchester LRP, and Federal 210 primers. Either of these are sufficient except for the STW, Weatherby, and Rem.Ultra mag. cases. For those, I would use the Federal #215.
I've never seen a problem with using a magnum primer either. Sometimes, depending on lot #'s, they are the cats "meow", especially with the spherical powders regardless of case capacity.