I picked up a Ruger American Rimfire, and I really like the rifle. I was shooting it this weekend with a SilencerCo Sparrow and the combo is really awesome. The temperature was in the low to mid 90's with a good breeze.
I've got a very limited stock of standard velocity ammo, a pack and half of Wolf 40gr and some Eley Sport.
The Wolf was super quiet, basically I'd pull the trigger, hear the action fall and then hear it hit the target. However when I shot the Eley Sport it sounded like it actually went supersonic out of the rifle. I'd shoot and hear the same snap that I got out of the Federal AutoMatch ammo I was shooting.
Is there specific ammo I should be looking for that will stay subsonic in a rifle? Was it just the temp that made the Eley Sport go supersonic?