Silvertips work well in the PM9/MK9. Both guns have very tight designs. Look at the bullet, and if it is a little taller than the usual, then you might have trouble feeding. The MK9 I have does deform the tip of Silvertips when either chambering, or extracting an unspent round. Weird but this does not seem to affect accuracy or reliability. The PM9 and MK9 are quirky pistols. Some run flawlessly (mine does). Others cause problems. Like I said, a very tight design.