Click but no bang - Sellier & Bellot 10mm 180 Grain Full Metal Jacket Brass Cased Pistol Ammunition

11 duds out of 30 rounds with a g20 gen 4. Ran side by side with Blazer 180gr with no issues going bang. Read that S&B rounds have "hard primers" ... but this is ridiculous. Looked more like an issue with compacting the round or bunk primers. Each dud round had a nice deep indent from the striker. Will try again with another firing pin but keeping expectations low... im using a g20 for heavens sake.