You can run a reverse trajectory for a good velocity. If you have an area you can shoot at extended ranges ( the farther the better), you can get a good velocity. You will need to download a ballistic app, input some basic rifle, bullet and atmospheric variables into the calculator. Then go shoot at a know distance. Input how many minutes or mils of elevation it took to receive an impact, and you should receive a reverse trajectory with a pretty solid velocity. Of course, given all your variables are accurate.