If you are using barometric apogee deployment, then you need to determine how the air will get to the altimeter. I normally do this with a hole at the bottom of the cone as Tim mentioned, and then holes into the airframe below the cone. The downside of this approach is that the altimeter sees the pressure spike from the deployment charge. I haven't had a problem with this, with charges generally located below the chute. A charge directly below the cone would be an issue though I think. Holes directly into the cone shoulder would require a mach lockout for any kind of extreme flight. You could do this with the timer on the Raven (setting a time "greater than" that allows the rocket to slow below transonic).
Whether you use barometric or accelerometer deployment, you need to be concerned about the accelerometer accuracy on the Ravens. Many of them measure low by about 30%. If you have one of these, you will reach V<400 too early (losing your velocity mach lockout when you might still be above mach on some flights) and V<0 too early (getting early apogee deployment). The easiest way to determine if you have one of these Ravens is to look at the acceleration on a flight with a commercial motor (where you have a simulation you can compare against). If you have one of the low-reading Ravens, it will be obvious. You can still use these, but you have to consider how to work around the issue (always flight specific).
Why is your deployment altitude so high? Planning to land on a mountain?
Jim