How long should it take?

My new irons will be ready for collection tomorrow (being gripped today).  The question is, how long should it take me to get used to them? 

I expect I will lose a little accuracy as the distance may be different, and may even miss left or right as the fit was different to my current set.  Then there is the feel change going from a 5.0 Precision Rifle to a stiff KBS Tour.  So the question is, how long before I get used to the new weapons?

Replaced the wedges a couple of months back Ivan.  They took me about four weeks to get the right feel with.  That was probably 7-8 rounds and 300-400 balls on the range between the two.  Didn't help that I changed the loft on one of them as well as the brand

Ivan , he had his last set custom ftted and has changed them before he  got used to them.