Strange sound while charging new rifle

[shrewd yasu]

I hope this is the right place to past this:

I just finished my new build today, and it feels great a 5 and a half pounds.

The only thing that confuses me is this really high pitched ringing sound that the rifle makes when the bolt is released. Almost like a tuning fork or triangle, just an almost unpleasantly high tinnnnnnnnng.

It's a seekins precision melonited BCG, Odin works stainless lightweight barrel, and a bcm KMR

At first I thought it was something with the spring, but now I've noticed it ever so slightly when letting the hammer fall or even closing the dust cover.

I'm unfamiliar with melonited anything, but it still doesn't seem normal

http://youtu.be/hFwwmlYplrw

[CleverNickname]

The rifle wouldn't happen to have a muzzle device with exposed tines, would it? If so, I'm guessing it's your muzzle device ringing like a tuning fork.

[OH58D]

I watched the video and it sounds like something coming from the recoil spring interacting with the buffer. Is there much play between the upper and lower? Have you shot it much? Run some ammo through it for a while and see if it stops or doesn't sound as loud. Personally, I don't think there's anything to worry about if it shoots fine.

[SomeOtherGuy]

As noted, this type of noise is most common with an open ended flash hider like a Vortex or AAC Blackout (although my Blackout doesn't do it as much as some other designs). The worst offender is probably the STG-58 long flash hider used on Austrian FN-FAL rifles.

I have experienced this from another cause however - I recently got an Aero Precision M4e1 upper with the 12" MLOK handguard and found it doing a high pitched ring from any tap of slam, despite an A2 flash hider on the barrel. The handguard itself was ringing. This was easily solved with a bit of MLOK slot cover and the ringing is gone.

Check your flash hider, and if it isn't that, put something on the KMR rail.

Melonite treatment is not causing this.

[shrewd yasu]

Good info everyone.

The muzzle device is a YHM flash hider (phantom, I think?)
And it hasn't been shot yet. My next guess was to put a hundred rounds or so through it and see what happens

[New Centurion]

I'd be surprised if releasing the bolt would generate the tuning fork effect that some FH's have when firing, but I'm no expert and am easily surprised. Applying a little compression to the FH should confirm or dispel whether it's the culprit. Heck, I'd triple check the empty chamber for safety and hold the FH around the sides to see if it still occurs. Of course, I don't recommend you do that when a tight rubber band around the FH should have the same result in a safer manner. It should be easy to isolate it to the FH or the buffer area.

The only unusual sound I heard when I fired my AR when it was new was a devilish kind of giggling every time I pulled the trigger. Sounded very close by and familiar, but I never isolated the source. Seems to happen with every new gun purchase, and even during a few first rides on new motorcycles.

[R0CKETMAN]

How does it sound with a loaded mag?

[P2000]

It is either your fh or the KMR. Hold the fh in your hand and do the same test. Hold the KMR firmly and do the same test. Either way, it isn't an issue. My surefire socom fh makes a similar sound.

[Neville]

Bolt a light on and the noise will be gone.

[Slvr Surfr]

What he said:



It is either your fh or the KMR. Hold the fh in your hand and do the same test. Hold the KMR firmly and do the same test. Either way, it isn't an issue. My surefire socom fh makes a similar sound.

[wahoo95]

Non issue, but it's most likely just the result of metal on metal contact generating a vibration.

Sent from my SM-N910V using Tapatalk

[shrewd yasu]

It's definitely the KMR

[cbx]

Put your free hand on various places on the rifle trying to isolate the tuning fork effect.

You could also add some lube to the bolt carrier and buffer.

Did you lube the barrel nut? Dumb question, I know.

I'm betting handguard also.

It'll probably go away once you shoot it a bit.

[556BlackRifle]

Get some keymod covers and that should stop it - if it bugs you - if not, just shoot and enjoy!


BTW, I have two rifles with Smith Vortex installed. They both ring when shot. I ignore it.

[RVTMaverick]

Actually, I don't think I have ever released any of my BCGs like that on an empty :eek: chamber..LOL

Does it make the same sound mag. in and a round going into the chamber?