stotler nock

[Ari_Bonn]

So  I acquired some of these, I hear they were howard hills favorite nock.     They are supposed to fit the shaft very flush but it seems  maybe they were meant for a different taper angle?  they don't seem to fit right.   when i  push them down  they crack easily,   im not sure if its the material or  if its due to old age id imagine they are quite old and the plastic could have become brittle.

[Gordon Jabben]

Always thought they were a cool looking nock but I have used the speed nocks for so long, they felt strange to me.  I have some and tapered an arrow just now and the taper on the nock seemed fine.  I even tried to get it to crack and it didn't.  I don't know if your nocks are white but for some reason the white ones seem to get brittle faster with age. 

[M60gunner]

I wouldn’t use them if they are cracking and breaking in your hand. Bows don’t like dry fires for one. Personally I didn’t care for them, the nock didn’t fit on my string to well. Didn’t seem deep enough

[Charlie Lamb]

I would be inclined to suspect the shaft taper. I've tried them a number of times over the years and always seemed to dry fire as many as not. I don't know how Hill did it. I have noticed that Howard's protege John Schulz prefers speed nocks.

[Jon Stewart]

I have maybe a thousand older plastic speed nocks and won't use them because of their age. Old plastic cracks pretty easy.

[dragonheart]

I would be inclined to suspect the shaft taper. I've tried them a number of times over the years and always seemed to dry fire as many as not. I don't know how Hill did it. I have noticed that Howard's protege John Schulz prefers speed nocks.

I am in agreement with Charlie.  I tried and gave up on using them.  The older nocks get brittle with time passing and the nock groove just did not work out.  After the dry fires, these were a NO GO.

[Ted Fry]

Not all old nocks are brittle , some I have on arrows from the 50's still shoot fine , Stotler nocks had a cracking problem from the get go.
Best thing to do if in question is to pinch the back end hard on the ears, if its brittle they will crack and break.
As Charlie said , I would suspect an incorrect nock taper, to fat on the back end of the taper and even a modern nock will crack, to long a taper and it will pivot on the end while not seating on the back.