Gill will attack two junior world marks at the North Shore's Millennium Institute on Monday night safe in the knowledge that he qualified for the London Olympics with his 20.38m throw this week.
Under a formula designed by Athletics New Zealand's former high performance director Kevin Ankrom, Gill's previous best of 20.01m in April had him on track to break Barnes' world record at the age of 27.
American Ankrom, now employed in Ireland, developed the system by studying the results and progress of the top 16 finishers in many Olympic and world championships. After Monday's Olympic qualification throw, the formula suggests Gill will break the 1990 record at the age of 25. Gill is already breaking a lot of rules, and isn't even happy with his form.
Gill said: "Things haven't been completely on track. My technique is the worst it has been for a couple of years.
"There were a lot of people there for a New Zealand shot put event on Monday night and I had some nerves.
"My coach was in Europe for a while and I got sick, and it is hard being 16 and training like a professional athlete, but I don't have excuses.
"To do a terrible throw and still qualify for London means I was quite happy, but the coach was just shaking his head going 'oh no' ... it may take four weeks or four months but I'm sure I can get back on track.
"A throw in the warm-ups would have got me fourth or fifth at the senior world champs so a lot of potential is there. The actual throw I did with that bad technique would have got me eighth. I definitely hope for a medal in London."
Terry Lomax, a performance director for Athletics New Zealand, has described Gill as (Usain) "Boltish" in the way he is re-writing the shot put rules.
"There has been a change in heavy throwing events towards speed which may be the result of good drug testing programmes, or also that people realise there is more than one way to skin a cat," said Lomax.
"Jacko has great hand speed and explosive power but the main thing is he really seems to understand his body, and how to train to get the best out of it.
"In Jacko's view it is full steam ahead and he's totally focused on being the best there's ever been. Those of us trying to provide a degree of support must not squash those thoughts while ensuring nothing increases the chance of him being derailed.
"Sport is strewn with brilliant junior athletes who haven't made it as seniors - that is not to say he won't do it, but until he has, who knows? There can be distractions ... but he's not motivated by money in any way."
Poppe says: "I have seen more talented athletes although they can tend to be lazy. The main thing about Jacko is his personality. It is hard to train that hard, to not be afraid of the pain and stress.
"This is not the normal behaviour of a 16-year-old. Teenagers are unpredictable, they like to party. So he is leading a life in some sort of double world and able to focus and be hard on himself in a way you only see with very, very top athletes.
"He is going to throw 21m in the not so distant future which can allow him to be in the final of the Olympics, a huge achievement for such a young person. It takes 10 years to build a shot putter - Jacko has done in two years what others do in 10.
"It's a bit like money in the bank though - do you use it now or will you have any left? He is training like an adult and improving further than any other athlete of his age, but will he keep improving?
"Is it possible to train harder and better? He may reach a level at which he just can't improve. You just don't know."
Until Gill came along, the greatest shot put prodigy may have been an American, Michael Carter, the 1984 Olympic silver medallist who was also a pro footballer.
Gill plans an attempt on Carter's junior record with the senior shot (7.26kg). He will also chase the junior mark of 22.73m with a lighter shot set by world champion David Storl of Germany.
