P.C.
We have EpiPens for our 2yo but thankfully have never had to use one. Yes, the practice one does take a decent amount of force and I am sure it hurts the child when you jab it in their leg. But, that temporary pain is nothing compared to not being able to breathe. This is meant to be used to save a child's life, so a little pain in the leg isn't really a big deal.
Be sure to have it with your AT ALL TIMES. Also, be sure to have Benadryl with you as well for more minor reactions. Make sure whoever has care of the child knows how to administer it and when to administer it. Also, make sure the child gets to the hospital immediately after an EpiPen injection.