As loud as any other centerfire caliber burning 28 grains of powder at 57,000 PSI.
Like a .223 for instance.
If you want a quieter caliber, look at .22 Hornet, .17 Hornet, or .17 HMR or .22 WRM rim-fire.
All are capable 200 - 250 yard small varmint calibers and won't wake the neighbors 1/2 mile away on Sunday morning.
rc