Moderator set up?

[oldsparky]

The rifles I have with moderators, I purchased them with the moderator installed. I have never had a problem with these. What method do air gunners use to insure their moderator is centered with their bore to be sure of no clipping damage. I have read some firearm silencer installers use a rod to be sure of center. But most air rifles won’t allow a rod inserted from the receiver end. I have read where some use a light and be sure there is no shadow. And some just stick them on and hope for the best. What do some use here?



Thanks

 

[mrbulk]

I have found that the likelihood of clipping is greater with shrouded barrels, and that a good adapter for accepting moderators will have some sort of barrel concentricity-maintaining device. For example the Donny FL adapter for the AV Avenger.

 

[kayaker]

Donny recommends one size up for guns with a shrouded barrels-- example 22cal. go 25 cal. mod. I found out the hard way . Sorry I have no clue of others but have heard of the rod being used . What gun you thinking about ?

 

[MikeVV]

Mmm, I don't know how many are actually having problems. Buying a quality silencer and screwing onto the shroud or barrel, SHOULD be just fine.

Hell, I took the shroud off of my Daystate Renegade, shortened it, so it and the air tank are the same length. Had the shroud welded back together. Had to shorten the baffles a little, had to shorten the spring that keeps the baffles snug, no clipping ! Then I took that shroud off, and put it onto the Pulsar that I bought, still great,,,no pellet clipping.

Now for the really interesting one. Even though the barrel / shroud on my Air Arms, Galahad are the short version, It was still too long for my taste. So yep, out came the hack saw. I don't recall how much I removed from the shroud, but it was enough to put the original silencer right against the barrel support. Interesting fact, though I haven't made it to the weld shop yet, just some heavy aluminum tape is holding the shroud halves together. Yeah, you guessed it, no pellet clipping.

With all of my hacking...and no pellet damage, I'm thinking that some of the problems, MAY be owner induced..!? Not particularly bad mouthing anyone, but if I can cut and weld a shroud, cut and "tape"...a shroud together and there is no pellet interference, you figure it out.



Mike

 

[Long_Gun_Dallas]

Shine a bright light into the breech and look. Its pretty obvious if the mod is centered or not. If not, I will face the back of it by hand. If pointing to the right too far, take material off the opposite side on the back. Slowly until it is right. Sometimes it takes multiple tries. But make sure it isn't the gun first. I face mine on a gun I know is true. So my mods end up being true on all of my guns. I have had some guns with plastic barrel ends that needed facing instead to get the mod to seat level. Again, just do it slowly. 

 

[elh0102]

What method? Just shoot it. If it's clipping, you will know it right away.

 

[Long_Gun_Dallas]

Not necessarily. Accuracy can suffer if pellets pass to close to the end cap or baffles. They don't actually have to make physical contact. Pressure waves will do their work 

 

[elh0102]

Not necessarily. Accuracy can suffer if pellets pass to close to the end cap or baffles. They don't actually have to make physical contact. Pressure waves will do their work

Rigbt, but shooting it would disclose an accuracy issue regardless of whether actually touching or not.

 

[oldsparky]

Thanks for the help? I don’t have a rifle that needs done right now. However I thought briefly about putting one on my Taipan. I even ordered an adapter that I wasn’t really satisfied with. But during these thoughts I realized I would like to be sure of fit instead of just hoping the moderator is centered to bore. I will look with a light on what I have to see if I can see well with that method 



thanks

 

[GeneT]

Properly done, a firearm silencer has threads, and most importantly a thread shoulder that are coaxial and square to the bore of the silencer. The barrel is then threaded (after production) to be concentric with the bore (*not* the outside of the barrel). 

Rods, shadows, and other voodoo are 'sanity checks' - they can help you spot gross misalignment, but you really need to go shoot to see if you have accuracy-destroying misalignment, or worse, clipping. Usually the 'sanity checks' will help you avoid clipping.

I usually just use a visual (shadows) and then just try it. OTOH, if the mounting seems wonky, wobbly, uncertain that's a screaming red flag. Fix it before proceeding.

GsT

 

[steve-l]

I make a test rod that is long enough to pick up the barrel and extend through the end of the moderator to make certain the moderator is properly mounted before shooting through it. I use precision shafting as a base and then test the barrel diameter at the muzzle with pin gauges. This step is necessary because of any choke used by the manufacturer, Once this diameter is known, I machine the test rod to match. I have found over the years that .020" or .5 mm is the optimum Moderator bore to pellet clearance. The rod allows you to make certain this clearance is uniform on all sides. If not, it becomes easy to determine where the misalignment exists. I can do this because I have a machine shop and the pin gauges. If you don't have these, find a friend that does.