2 questions?

On question #1 I use a moderator to keep backyard shooting noise to a minimum which keeps nervous neighbors happy. At the range less noise makes shooting mor enjoyable and for hunting less noise to scare off game.

on question #2 I’ve never done shims so I just don’t know I think that there is a scope ring that has a windage adjustment from sports match.

1. Yes, for pneumatics it reduces the report. For springers, not as much.

2. You have to shim the stationary side of the clamp. If it’s hitting left and the stationary side of the clamp is on the left, you should shim the front ring. If the stationary side is on the right, shim the rear ring.

Different air guns make different amounts of noise levels. Some are a bit louder than others even though it’s not a supersonic crack. Moderators will bring this noise level down to almost nothing, depending on some factors. 

Josh,

You might consider getting adjustable rings. Checkout Sun Optics.

Rick

1. Yes, for pneumatics it reduces the report. For springers, not as much.

2. You have to shim the stationary side of the clamp. If it’s hitting left and the stationary side of the clamp is on the left, you should shim the front ring. If the stationary side is on the right, shim the rear ring.

Click to expand...

I can only speak for my particular gun in this regard because I have no experience with others & not many offer a threaded barrel, but a moderator definitely makes a difference on my Walther LGV. Not on the same level of my pcp, but worth it in every way. 

I agree a moderator helps allow me to shoot in the backyard without the worry of neighbors hearing me target practice. I have both a fx impact with a koi in .22 and a fx wildcat .25 with a sumo on it. Both have the noise considerable decreased by the moderator. 

My AirWolf without the moderator sounds like a 22 rimfire. With the moderator, the pellet impact is louder than the report. 

I have had vertical adjustment issues and I was able to fix it every time by removing the rings from the scope, and gun then reinstalling the whole thing. If you are using budget rings you may have to change them front to back, and sometime even flipping them around.

Actually a 1pc mount is preferable because it avoids applying torque along the scope’s axis when you install a shim for windage. Cut your shim about 1/2” - 3/4” long and apply it at either the front or back based on my earlier explanation.

The shim will affect how well the mount holds to the dovetail so make sure the surfaces are clean (oil free) and torque the fasteners per the mfg recommendation.

Question 1: In NY state, even if I apply and pay for an Alphabet org tax-stamp, 
it is still 'illegal' for me/us to own/use suppressors on our powder-burners..
That really p**ses me/us off!
So... I use suppressors on my high powered PCP air rifles to thumb my nose at NY.

On a more serious note.. I do a LOT of indoor shooting..
The noise levels from the guns are loud to begin with, and being indoors only 'amplifies' that, 
as well as the echos from shooting in a confined space..

Using a suppressor completely eliminates all of that..

I suppress all of my PCP air rifles now for that reason, and love it..
When I pull the trigger, I hear the hammer/valve, and the pellets hitting the target/backstop..
No more loud dog barks.. Only quiet mouse farts.

Question 2: Has already been answered really well.

 

Sam -

Moderators make a big difference in the sound levels of a PCP, but not so much with a piston gun.

Whether you shim the front or the back, just aim the scope toward your existing POI. Point the scope toward where the pellet is hitting.

Get the adjustable rings. Worth it . If you have an 11 mm dove tail on your gun you really can’t shim the mounting point you will have to shim the ring area . There is the right way and the wrong way. Do it the right way you’ll not regret it.

Sportsmatch rings.

regarding Q 1. Yes it reduces the "pop" of the air rifle. Since the "crack" is a result of the pellet travelling faster than the speed of sound it occurs after the pellet has left the gun barrel or moderator and the moderator cannot stop the super sonic crack. Diablo pellets do not fly true above the speed of sound. they "wobble", so no crack- we limit pellet speed for accuracy. (Shooting slugs or bullets another story) Moderators do have a quieting effect on the "pop" of air rifles especially pcp's. The air is compressed and begins to expand down the barrel. Longer barrel less "pop". Essentially for air rifles moderators provide an enclosed space for the compressed air to expand while retaining, impeding the sound waves. If you pop a balloon in an enclosed space it is much quieter outside the enclosed space. If You install sound absorbing material in the enclosed balloon popping space, that will have a silencing effect. but the space inside the moderator is small and the material has a small effect on the "pop". The impeding by baffles can also affect sound by redirecting it. But space limitations also play a role in that. The factory barrel with telescoping baffle sleeve on my FX Impact works well for me and the moderator on the FX Bobcat ( Not wildcat ) works equally as well. Powder actuated firearms are a different story. The expansion space is still necessary. The baffles, screens and metal wool are there to cool the gases . Removing the heat from the propellent gasses reduces the rapid expansion of the gas and the "pop" is substantially reduced. Firearm silencers burn out and require repair. Explosions are the rapid expansion of a gas. Electrical arcing causes the air to rapidly expand and depending on how much power is "released" controls how much air expands and how rapidly it expands. And how loud the bang is.