A lot of people overcook their food in the pressure cooker because they just can't believe it will be fully cooked in such a short time. So they add 5 min or 10 min or even 20 min to a recipe's cooking time. People tend to forget that while your pot is coming to pressure, it is already getting HOT inside the pot and your food begins to cook. The heating up and pressurizing time can take 10-15 min. So your food begins to cook as soon as you turn on your pot. Your food is also still cooking while you NPR, another 10 min. So always keep that in mind before you start adding time to any recipe.
These are pretty good size meatballs. I was able to make 9 that were about the size of a extra large egg when you make them in the mold. They weigh just under ¼ lb each when cooked and drained.