The guns we used for testing purposes were our Benjamin 397P pump up for the air gun, since pump ups are fairly loud as air guns go, since there is no potential for adding a shroud or moderator as on a PCP.
For the 22 LR, I chose one of my favorites in the Winchester 1885 Low Wall Hunter 22 LR with its 24" barrel. This is not the most accurate 22 LR we own, but it is no slouch and it's a gun I know very well. Definitely one of my favorites.
Ammo for the 22 LR consisted of 22 CB Shorts and CCI 22 LR Quiet.
Loudness test
My sound judge was my husband Bill, who stayed up on our raised deck, while I did my shooting down in the yard on our 30 yard range, a good 20 yards from Bill.
I started off shooting the Benjamin air rifle with 4 pumps and followed with the CB 22 Shorts. I repeated the test four times. Bill rated the CB Shorts as just a touch quieter than the air gun with 4 pumps.
I then switched to the CCI 22 LR Quiet. Bill rated it as just a touch louder than the Benjamin air rifle with 4 pumps, but rated the CCI Quiet as just a touch quieter than the Benjamin with 6 pumps.
Conclusion: The CB Shorts and the CCI Quiet were very similar the Benjamin pump air gun in loudness. Not really surprised, but good to have it confirmed. When shooting either type of gun, the noise of the projectile hitting the metal backstop would be louder. Note that neither the Benjamin pump or the 22 LR rifle with CB Shorts is as quiet as a PCP air rifle with a moderator, but pretty close. I would still rate both as passing the backyard friendly test.
Accuracy
Here's where the quiet rimfire loads take a hit. This kind of rimfire ammo is not target grade ammo. It's definitely not match ammo or 50 yard ammo. It's designed for short range work, the closer, the better.
CB 22 Shorts.
At thirty yards, accuracy was pretty bleak, even with the excellent Winchester single shot. I had no luck getting 5 consecutive shots without a flier. At 30 yards, the best I could do was two decent shots and three flyers. I would highly recommend keeping distances 20 yards or less with any CB round.
CCI 22 LR Quiet
I did much better at thirty yards with the CCI Quiet. I still got a few fliers I blamed on the ammo, but only on an every now and then basis. Groups could still not match the third of an inch groups I can get with the scoped Benjamin pump or one of the PCP air rifles at 30 yards, but I did get half inch groups at 30 yards often enough to know they weren't flukes. Here's one of them.
For the sake of comparison, this half inch group shot with the Winchester single shot at 30 yards with the CCI Quiet matches what this same Winchester Low Wall can do at 50 yards with premium 22 LR Match ammo.
Conclusion
To wrap it all up, Bill and I are quite pleased that we can shoot our rimfires in the backyard with quiet rimfire ammo and be no louder than than when shooting our airguns. Accuracy at 30 yards with the CCI Quiet won't quite keep up with our high grade air guns, but is still good enough for serious practice shooting. (Only issue, now, is availability on CCI Quiet and other types of rimfire ammo.)
Life is good.
