No amount of jerking will get him to stop, though he is fine when we are returning home. The chain is also rubbing all the hair off his neck. Should I use a collar instead?
As he has had the same routine for a while, it will be difficult to correct his pulling on the lead unless there is a complete change in your approach.
The choice of lead will not cure the problem; only patient and sensible retraining will see results.
The use of a choke chain, and allowing him to pull on it to the point of hair loss, is not fair and should be stopped immediately.
This also applies to any other type of collar or lead that is used. Go back to basics.
Putting the lead on should not be a cue for a walk, but a cue to pay attention and to earn rewards.
Refresher lessons with the lead attached should be carried out.
Make him sit and stay, with eye contact, then take a step forward, come to heel and sit again. Praise all eye contact to build his focus on you.
When you take him out again, vary where you go, and if he pulls even once on the lead, turn around and go the opposite direction.
Consider driving him to the exercise area and remove all the situations that might cause confrontation.