Need help diagnosing problem in AR 15.

[EHL]

I have a brand new AR 15 that I just finished building up and I put a PRS stock on it. Only problem was, the original factory screw that goes in the rear wasn't in the package. My gunsmith installed his own though. I went to the range and it functioned, except every time the gun fired it sounded like a a slinky was going back and forth inside of the buttstock. I have another AR and it does NOT make that loud obnoxious sound with every shot. It functions fine, just sounds very odd. Any body have a PRS that makes this sound or even just an A2 buttstock being super loud and annoying like this?

 

[flyboy1788]

most ARs make that noise. Learn to cherish that noise, there is nothing wrong with your gun.

 

[kwelz]

That is the sound of pure joy as it goes downrange.

 

[dawgtraxx]

put a little wheel bearing grease on the spring, it will quiet it down

 

[61chalk]

I had this problem, or at least it is close...too loud of sprong noise an what seemed like very slow bolt action...it turned out it was the buffer spring getting very weak. I replaced with a new one, an in pulling the handle back to load, I noticed it was much stiffer...it made a big difference in the sound an bolt action. It sounds like a weak buffer spring from what you have said, try swapping springs since you have another AR, unless you have different length springs for different length butts on your AR's

 

[Rubber_Duck]

DON'T PUT GREASE ON THE SPRING!!!! The buffer tube and everything inside it should be dry, lubrication of any kind will only make it dirty. The muffled "sproing' sound you hear is just the AR-15 heart beating.

 

[PT1911]

normal... not a problem...though I have heard the suggestion that that very sound could scare the deer away:banghead::banghead::banghead:

 

[jpwilly]

If you listen to the "sprong song" carefully you'll even know when your out of ammo...

 

[W L Johnson]

normal... not a problem...though I have heard the suggestion that that very sound could scare the deer away

I can picture it now, After the bullet hits and a loud bang one deer looks at the other and asks "did you just hear a sprong sound?"

 

[briansmithwins]

DON'T PUT GREASE ON THE SPRING!!!! The buffer tube and everything inside it should be dry, lubrication of any kind will only make it dirty.

Really? The manuals I've read say that the buffer and spring get light lube.

Not lubing moving parts because they get dirty just means that dry dirty parts wear more or cause stoppages. BSW

Manual page that talks about lubing the buffer: http://www.ep.tc/problems/25/12.html

 

[Rubber_Duck]

BSW, That makes sense, however I always keep that part of my AR dry, keeps it from getting dirty and I haven't noticed any adverse effects of running the spring/buffer dry.

 

[PT1911]

I can picture it now, After the bullet hits and a loud bang one deer looks at the other and asks "did you just hear a sprong sound?"

exactly... and the worst part.... now they know where you are.. most dont know.. it is also the sound that throws them into a murderous rage.. much like red to a bull...

 

[Crawfish141]

Learn to love the sproing!

 

[EHL]

thanks for all the replys guys. I added some oil to the buffer tube(without taking the thing apart) and I think it seeped into it. I went and shot my AR and the loud noise is gone. I can still hear a little bit of movement, but nothing like it was before. Seems like it just needed a little bit of lube.
Thanks guys!

 

[offthepaper]

Learn to love the sound.
It's the modern day version of "ping".

 

[larry starling]

Oh no its broke send it to me and I will check it out........LOL!

 

[Uncle Mike]

That sprong noise is why we got our butt kicked in Iraq... Gave our troops positions away. Your gun is "no good"... send it to me and I'll take a look at it just ot be sure, if it indeed is faulty I'll give you a good price for it. hehehehe

 

[kanook]

I use a silicone spray on the spring, let it dry, then use it, no problem

 

[Maverick223]

I use a silicone spray on the spring, let it dry, then use it, no problem

+1 for silicone, that stuff is great. I constantly used it and wet and dry type graphite lube when I had my air compressor repair business. It is a good lubricant that has no adverse affects. It will stay/last, is non corrosive/safe for rubber and plastics, has a low static/dynamic coefficient of friction, and is even safe to consume; although I don't know how good it tastes on a hot dog .

 

[Rubber_Duck]

+1 on silicon being safe and inert. It is the only lube that is safe to use on restuarant equipment where it can come into contact with food (for example, the seals on an ice cream machine at your local McDonald's are lubed with silicon grease).

 

[ol' scratch]

I lube mine buffer with CLP break free. It too makes that sprong noise. I like the sprong noise, it makes me happy.

 

[otrman]

"My gunsmith installed his own though"


One thing to check is the factory screw that comes with the PRS is about 1/2 inch shorter than the screw used in the factory A2 buttstock. If the screw is too long that could cause an issue.

 

[offroaddiver]

That sound to me means i have a good weld on the stock. At first I thought it sounded alot like a spring doorstop being plucked.