I did it in the TA a couple years ago, just messing around. I took off from a '0' alt field, no wind, just a full bag of gas. The trick is to get it climbing at it's best rate of climb (it's around 200mph for the most part IIRC).
If you want to get higher take off from a field with higher elevation. But remember that the higher you climb the lower your climb rate is going to be.
Also, if I remember right, I got rid of my ammo before taking off. (less weight).
cheers,
RTR