Charlie, they end up being about 3 1/2 inches long.
I use a water glass to cut out the circles, then roll them in longer ovals. I made the balls of filling almost the size of golf balls. They flatten a bit when I pull the dough around them and pinch it shut.
Don't over roll the dough. Another trick to try is add a tablespoon of sour cream to the dough and less water. Be sure and let the dough sit at least five minutes away from any drafts in a covered glass bowl before rolling.
I had to laugh when I saw the title of this post. A few years ago I decided to learn how to make pierogies when an aunt passed away taking her culinary secrets with her. We rooted around our house and found my departed mother-in-law's cookbook that had been translated from Slovak to English. the recipe said, "Take some flour and add a pinch of salt and some water. Add an egg....." I fear something was lost in the translation. so I did just what is said guessing how I used to watch Mom and Dad make them when I was little kid and you know what? The first ones were ok. I would like to think they have improved since then but I know better.
I am still having a problem finding the right sized circle to cut. The top of a margarine container works ok. Any suggestions?