10 replies to this topic

[elf avec gun]

So I was range testing my Ls today because it was really nice out. And as many of you know, when a modified Ls (+BBB spring, -ARs) is fired it makes onehelluva bang. Something like this tends to give away one's position. So I'm wondering if shortening the plunger rod just a little bit (so that the plunger head doesn't hit the front of the inside of the inside of the plunger tube) and reinforcing it with some sheet aluminum (so the force of the spring doesnt pop the plunger head off or crack it) would help to make the thing quieter.

This would go for most other spring powered gun with this type of set up too (I would think)

EDIT: I realized that I forgot to say that the springs would have to be shortend and/or connected in two places: the back of the plunger head and the place that the other end of the of the spring rests on.

Edited by elf_avec_gun, 15 October 2006 - 06:20 PM.

[bigbob]

Take the nitefinder for example with this modification. The cocking handle is always an inch away from the case of the gun. If you were to shorten the plunger rod, the cocking handle would keep on going until it hit the casing or the end of the plunger tube, whichever comes first. This would make a slightly quieter sound from normal, but not enough to be effective. Basically what I am saying is that it would be easier to put some foam on the plunger head, and it would nearly silence the gun.

[six-five-two]

Before you try using the Longshot, use a cheaper gun like the Nitefinder. So if you make a mistake you won't lose $30.

[funkyjake]

Putting foam on the end of the plunger head sounds interesting, but I'd be cautious around shortening your plunger. I have no actual experience here, so don't trust me on it, but I'd think messing with your plunger's length would very much decrease your gun's air output. It's an interesting idea, though, and I can see how you'd arrive at it.

I'd also mention that people in airsoft sometimes lightly spray the inside of their rifles' cases with expanding foam wherever there's room to do so. Where sound is concerned, Airsoft guns have the same problem spring powered nerf guns do, which is that the mechanism working, not just the sound coming out of the barrel, makes the most noise. I guess they find that muffling it is a good idea.

Anyone know what expanding, spray-on foam might be called? Packing foam, maybe? I can't remember.

[elf avec gun]

I have used the foam on the plunger rod before and although it does decreas the noise some it also might damage the plunger. This is because when the plunger is launched forwards, upon impact with the end of the plunger shaft, the plunger head and rod are forced to compress. Now depending on the malleability and docility of the plastic the plunger is constructed of, the plunger may shatter.

When foam is placed at the end of the plunger head, the shock is dampend some but it also occurs earlier on when the spring is supplying more force. So in effect the stress on the head is still about the same as before but the gun is silenced some. Now what I am proposing would get rid of both of these issues.


That expanding foam stuff is called expanding foam. That is an ineresting idea, filling the gun with it, but there would be problems with keeping it out of the plunger shaft and out of the way of other moving parts but let me think that one over and I'll get back to you.

[Falcon]

Take some spare FBR and wedge a bit of it between the the spring and the plunger shaft. Don't bother putting anything on the plunger head; that's messing with how the gun actually fires, and the less messing with that you do, the better.

In the LS's case, you should also put some BR in a few places on each end between the two springs to keep them from rattling against each other.

I have this foam vibration reduction in both of my crossbows and my Quadded Nite Finder. NO more rattling whatsoever. There really isn't much you can do about the bang that is heard when you fire, but I don't see a reason to. Dampening the vibrations of your spring in this way will make it so much quieter you won't even want to mess with silencing it anymore.

[elf avec gun]

My springs aren't bouncing around at all, they are long enough. I have tried the foam at the end of the plunger shaft as well but the shock caused by the collision is still present. I am trying to do two things: quiet the sound some, and eliminate the stress on the plunger.

[pat 1st Lt]

I am trying to do two things: quiet the sound some, and eliminate the stress on the plunger.

Your first goal is achievable. Your second is impossible unless you can rig some magnet-driven, near frictionless plunger setup.

I take it you know how a plunger works. Stress is it the basic princible it works on. Compression and release of a spring pushes the air-tight plunger which compresses the air as it moves. That compressed air then has to push the dart out of the barrel to equalize the pressure.

You cannot take the stress off the plunger. You can only reinforce it. There is no way to lessen the forces acting on the plunger without afffecting the range (Which I assume you want to stay close to what it currently is). For the Longshot, I would suggest doing what many others have done: take two aluminum washers, a neoprene washer, and a heavier screw and replace the plunger head assembly.

You don't have to worry about the plunger shaft breaking. The shaft is essentially a guide. It has very little stress on it. The highest stress point is the connection between the shaft and the plunger head assembly. Reinforce that, and you're set on the durability front.

Now, you're not going to believe this, but try it before you dismiss it: put some FBR between the shaft and the springs. Much of the noise is the springs knocking each other and expanding. Another tip: glue the springs to the back of the plunger face. By doing this, you will eliminate any rattle that goes on, since the springs won't be able to bounce back and forth between the plunger face and the back of the plunger tube.



*Fwheew* That took a long time to type. Hope it helps out a bit. But, realistically, you are not going to get a Longshot very quiet. You'd be better off taking a look at this. It was a very quiet rifle when finished. If you want something to fire from a concealed location without detection, don't take a Longshot.

-Pat

Edited by {SF3G}pat 1st Lt., 16 October 2006 - 12:14 PM.

[LastManAlive]

I didn't really take the time to read the other posts if this solution is in there...but I just use a swatch of felt or craft sheet on the plunger head held on with hot glue in between and then put the screw on. It makes it a LOT quieter.

[LordoftheRing434]

When I messed with placing foam on the plungerhead, I put it one the backside, separating the spring from hitting the plungerhead. It silenced it quite a bit, but there's no way of totally eliminating the bang.

There have been many a post on this topic too. Searching around may help.

[InkJet]

Yeah, foam on the plunger head significantly reduces noise for me too. If you don't have foam sheet, just cut a little piece of FBR and glue it on the end of the plunger. When i did that to my NF, the *pop* of the dart leaving the barrel seemed louder than the bang of the plunger.