We were sighting in a brand new Mk2 GL with a Nikon 4X yesterday. I loved the trigger. After about 15 rounds or so, it failed to extract the empty shell. I can remove the empty shell with my finger nail. We were testing with a CCI Blazer. The extractor is new and sharp. It doesn’t do it every round. It would fail after 4 shots or so. We did let the barrel cooled down between shots. We will test it with a different brand. Is it a common problem with MK2?