HP5 developed at 1+19 using Ilford developer for the advised 6:30 works just fine...................

even when the developer is Ilford PQ universal paper developer instead of the usual LC29. Whoops!

Actually its very slightly more grainy than normal, which was what got me thinking, but it wasn't immediately obvious what I'd done. The give away was I remembered the foil on the bottle I used was only punctured, and my LC29 is completely stripped off!