Gronitz PCM Mouthpiece Receiver size

[mdc2d]

Hello,

I've had a PCM for about 5 years now. Most of that time I have used a Bruno Tilz M1 mouthpiece. I've always noticed the Tilz mouthpiece did not go in very far, but it did not wobble around like other mouthpieces I have tried (obviously different shank sizes), assuming it was a proper fit. I had an old Blessing 18 laying around the house, so I decided to stick it in to see how it sounded (just curious). Immediately I noticed the 18 inserted much further in the receiver about a .25"), and it does not wobble around either... seems to be a pretty good fit.

The 18 sounds much different and some notes feel as if they slot better, others maybe not so much.

What's the deal?