Moderator help needed

Hi there all in PCP land!



I'm trying to tame an Impact MKII (700mm) in 22 caliber that's pushing 32 grain slugs out at 950' per second and it sounds almost as loud as a rim fire.

it has the standard Donnie FX moderator. Can anyone tell me what the quietest option is between the Koi, a Hugget or a Silent Thunder ? I've heard they are all good



Thank you for any input you can share on this!

Jimmy
 
I'll third the recommendation to turn the power down. How far below max fps for your current reg pressure are you tuned?

I usually tune around 96% of max (at that reg pressure) for best intersection of efficiency, noise, ES/SD, and accuracy. If you are at 100% then the valve is likely still open when the slug exits the barrel and it is wasting air and causing excessive noise. This is usually less accurate as well. I can even hear a change between 95% and 96% speeds so it makes a significant difference.

At ~96% tunes I can hear very little difference between the Donnyfl Sumo and Ronin for my M3 .30 700mm, even at 97ft lbs and 150bar reg pressure. It is pretty mellow and nowhere near rimfire. Based on this experience, I'd recommend the Sumo as the best all around Donnyfl moderator in case you can't get it quiet enough with the Donnyfl FX (which is shorter and smaller diameter than the Sumo). But dial the tune back first and see how it sounds with the moderator you have.
 
Hugget,STO and Donny all have several moderator units from which to choose so it would depend on which you choose which is better. 

Just get one that is a bit bigger, like at least a couple of inches longer, than what you have and it should do fine. Longer is better.

My .30 M3 sniper had quite the report with the stock moderator. So, I put an STO Sarrissa on it and it really quieted things down. But I guess it should as it is twice the size of the stock unit.
 
Thank you so for your responses and input. 

I haven't been able to get on the forum for a couple of days but thank you

I'm going to try a **sumo** (corrected) and see what that will do, if not perhaps a hugget or one of the other suggestions. 

Will post updates here but as this gun just got tuned by Ernest himself, I'm not keen on playing with the power just yet. I'm sure it's a great shooter, just wicked loud in its current state. 
 
I agree with many here. It sounds like the valve is still open when the projectile leaves the muzzle. Bring back the hammer spring a bit, and probably the pressure as well. tune to full power, and cut it back by 3 to 5%. this will have the projectile still in the bbl. when the valve closes, and the report will be substantially less, even thought he fps will be near the same.

Knife.