Pinesap,
Here' s a clip of a post I put onto this board a few days ago:
What didn’t work for me: As a fan of Precision Bullets products, I was keen to try their 209 to .22 Hornet primer conversion. I sent in a new breech plug to Precision, had the work done and went to the range. On the first try, the gun did not fire using 100-gr. 777 and a 348-gr. Powerbelt. The primer was spent, but the weapon did not light. I put in a new primer and repeated and repeated and repeated. I had to pull the breech plug, push out the powder and bullet. I reloaded using the standard 209 primer and everything was back to working. After a few rounds using the 209 primer, I went back to the .22 Hornet breech plug. Everything worked now, for about 10 rounds. Then the flash hole got gummed up enough that the .22 Hornet primer could not light the gun off again. I repeated the entire scenario again a week later and I again found that the .22 Hornet primer would not consistently light my gun. I’m not trying to start any controversy, but in my hands, I can only confidently expect my gun to light with the 209 primer.
I hope this information helps someone.

Bill the Dog