I had to buy a 60X magnifier to see the micro dates, a lot of the 2016 coins are not minted very well as we all know and this is why some of dates are not clear. Some of the 2016 coins are that badly minted the micro date doesn't show at all, the 2017 micro date is usually quite clear. you can pick up a 60X electronic magnifier for less than £5 on the auction site.
I think a lot of people must be reading the question wrong, I don't believe nearly 30% of readers have a dual dated 2016/17 coin, my daughter bring home 20 to 30 new pound coins every week day; plus 160 I managed to get on the second day of release.
Somewhere between 1500 and 2000 coins checked and no dual dated coins, these coins are as rare as hens teeth, people are not advertising any on the auction sites, if they did they would easily make £100, in actual fact if any of you 30%'s would like to sell me theirs, then I am offering them that amount if they wish to sell.
Also out of all of these coins only 2 had the milled edge to the left of the shield, I have bought 2 on an auction site, so have 4, not many of these on the auction sites either.
I think you should hang on to these coins.
If Bazza has found 14 of the dual dated coins in a bag of 20 it looks like the normal ones will be the rare ones. Hang onto them they will be worth a Mint lol.
In a bag of 20 that l have there are 14 with dual dates, hardly rare if you look for the dual dates
Local paper confirmed and how you looking at it you need a scope to see it clearly
I've looked at 50+ £1 coins and none have micro lettering remotely as crisp as the one shown. I think owner of that coin is pulling a fast one and showing an image from a proof 2017 coin and pretending it's a circulated 2016 coin.
Looking at my circulated £1 coins I could claim to have several that say "2010" and one that says "UUUU" and one that says "JJJJ".... reality is they are just roughly pressed.