Hi

I use Hobby's and GECO's in mine - the Hobbys are a tighter fit but after 15k of them through the barrel, it seems to have loosened up a bit or I'm just getting better at seating them

Have you tried shaping your grip - I could barely shoot mine for more than 10 mins when I got it but a few hours whittling away and it fits like a glove:

I've put some photos here:

https://goo.gl/photos/2kYTyzMKupZ7ZVjK9

These also show my adjustable bench reset and the wedge I made for my IZH46m.

You could join us in the MPL - your IZH should be perfect for the job.

HTH

Paul