Moderator clipping question
- By subscriber
- Barrels & Muzzle Devices
- 28 Replies
steve-l,
You assume too much. I started making mods for my own airguns, based on the idea that the smaller the baffle bore clearance, the better. Since then I have done hundreds of custom mod designs for people, included members of this forum. Some of those clipped, until I opened up the baffle bores to tolerate more misalignment.
As for the effect of projectile to baffle bore clearance on sound reduction, I had volunteers on the AGN and GTA forums participate in a study, so that I was not the one generating the test data, and could not be accused of injecting bias.
The study consisted of three identical 3D printed moderators intended for .22 caliber The only variable was the as printed baffle bore diameters. Specifically three moderator variants with 6.5 mm ; 7.5 mm and 8.5 mm baffle bores, respectively. In other words 0.5 mm radial baffle bore to projectile clearance, 1 mm radial clearance, and 1.5 mm radial clearance. The loss in performance for nominal 30 FPE .22 PCP rifles, going from mods with 0.5 mm radial clearance to 1.5 mm radial clearance averaged at 2 dB. A smaller loss in performance than I predicted.
While there are people that argue the sound energy difference at 2 dB is significant, the fact is that not everyone is certain they can hear a difference until it reaches 3 dB. So, in my opinion arguing about 1 dB is pointless. More important is if the moderated airgun report sounds like a firearm at a distance, or something innocuous.
Your approach may be the best way (for you), but how many people will accept needing to verify and adjust their moderator alignment, every time after removing and reinstalling it? They are generally installing commercial mods and want them to work well enough, right out of the box. Don't take my word for it. Interested parties on this forum can speak for themselves.
You assume too much. I started making mods for my own airguns, based on the idea that the smaller the baffle bore clearance, the better. Since then I have done hundreds of custom mod designs for people, included members of this forum. Some of those clipped, until I opened up the baffle bores to tolerate more misalignment.
As for the effect of projectile to baffle bore clearance on sound reduction, I had volunteers on the AGN and GTA forums participate in a study, so that I was not the one generating the test data, and could not be accused of injecting bias.
The study consisted of three identical 3D printed moderators intended for .22 caliber The only variable was the as printed baffle bore diameters. Specifically three moderator variants with 6.5 mm ; 7.5 mm and 8.5 mm baffle bores, respectively. In other words 0.5 mm radial baffle bore to projectile clearance, 1 mm radial clearance, and 1.5 mm radial clearance. The loss in performance for nominal 30 FPE .22 PCP rifles, going from mods with 0.5 mm radial clearance to 1.5 mm radial clearance averaged at 2 dB. A smaller loss in performance than I predicted.
While there are people that argue the sound energy difference at 2 dB is significant, the fact is that not everyone is certain they can hear a difference until it reaches 3 dB. So, in my opinion arguing about 1 dB is pointless. More important is if the moderated airgun report sounds like a firearm at a distance, or something innocuous.
Your approach may be the best way (for you), but how many people will accept needing to verify and adjust their moderator alignment, every time after removing and reinstalling it? They are generally installing commercial mods and want them to work well enough, right out of the box. Don't take my word for it. Interested parties on this forum can speak for themselves.
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