Frank - Your pup is still, well a pup. I wouldn't get in any hurry to introduce the ecollar. You need to first be sure he understands the recall command on leash/check cord in all kinds of situations. That can take hundreds of practice recalls. Then I would take him off leash in controlled settings and practice the recall. Then you have to condition to the ecollar. I don't typically even think about an ecollar until they are 7 or 8 months old at the earliest, and I practice recalls with my pups every day starting when they are 8 weeks old. I make it a game and make it a whole lot of fun while they are puppies, and don't start the serious recall training until they are 6 months old.
Also, some dogs take a whole lot longer than others to get to a reliable off leash recall. Ringo, my male pup, got it when he was 8 months old. Halo took until she was 2 years old to get a reliable recall.
Don't get in a hurry though. It is harder to fix a messed up recall than it is to take the time and do it right the first time. Also, don't use your recall word if you are not in a position to reinforce it.