I make prinskorv 3-4 times a year and it is my favorite sausages. Perfect for breakfast, lunch and supper. When I started making sausages for 6-8 years ago, I got a butcher's book with recipes off different Swedish sausages. The problem is that all the recipes were at 100kg sausages. This recipe comes from the book but I have recalculated the amount to 5kg sausage. With 19/21mm casings you need 30-35M becourse you will get about 270-280 sausages.
1.2 kg minced pork
1.0 kg minced backfat
0.4 kg minced veal
0.4 kg minced beef
217gr potato flour
80gr salt with nitrit
145gr milk powder
1.4 liters of ice-cold water
2 pinches of ground dried ginger
2 pinches of ground white pepper
1 pinch of ground nutmeg
Mix all the meat with salt, potato flour and spices. Dilute with milk powder and add the backfat. Mix everything in 10 minutes before diluting with the cold water. Just pour in a little water at a time, imagine that you should make mayonnaise. It will not be good if you pour in all the oil at once, just take it easy.
Fill the mixture into 19-21mm casings, braid as it looks in the picture. smoke the sausages for 1-2 hours until they are nicely browned at 75-80°C, and then simmer them for 20 minutes in 80°C salted water with whole white peppercorns and bay leaf.
I guess this recipe is very similar to ordinary frankfurter and it probably is too.