I finally got a chance to load some heavy and slow 9mm, a 147gr blue bullet over some W231 for about 925fps (as chronoed with a G34). Out of a G19 with a Rugged Obsidian 45 in short config, this load was significantly quieter than the factory 147gr lawman I had been shooting. Not so with the Extar using the same can, it was not hearing safe in my opinion. Do you guys think this is solely attributable to the unlocked blowback system and noise coming from the ejection port?