do i really need a small base die to load for my ar15 thanks mike

No one can tell you the right answer...all depends on your rifle's chamber. My Colt AR used in HighPower competition has seen several thousand rounds, all using standard RCBS or Hornady dies. Several friends also with AR's from various makers have never used anything but standard dies.
But your rifle MAY have the minimum spec chamber, where SB dies are needed....
If you have calipers or micrometer, you can compare a fired case against new ammo, or a spec drawing, to give you info on what may be needed.

I doubt it - i've never needed them in any of mine, including a really tight chambered J&P, which won't even chamber things like wolf ammo

I have loaded for several AR-15 type rifles, including many with custom bbls. I haven't used small base dies.