Lord Ripon who bagged over a half million pheasant in his lifetime insisted that barrel construction had a direct impact on gun headache, a problem which can be partly blamed on gun noise.
My theories on this stem from precharged airguns and there excess air volume definitely increases the sound, leading me to theorise (not prove) that bore volume relative to gas generated has a bearing on the noise level. All we need to investigate the phenomenon is equipment to measure gas volumes, noise levels, a private range and a government research grant.
