6 out of 7 is a good result. May be humidity too low at hatch time Suziequeue and it stuck to the membrane, but more likely the mother's diet and the chick wasn't strong enough or didn't have enough energy to get out. To get the best hatch you may find feeding rearer pellets and plenty of fresh greens 5 days before you start collecting the eggs until the last one gets results. Layers pellets are formulated for strong shells and yellow yolks, neither of which you want for hatching. What you do need is just sufficient shell and plenty of vitamins plus trace elements which is the formulation of growers pellets. We actually mix layers to rearers 1:3 just to be more sure of the calcium levels. Rearer is 1%, layers is 3%.