The Russian Mosin Nagant Forum

Took the Bushmaster AR15A2 out today, overall it shot great with no malfunctions at all.

I noticed what feels like a vibration in the butt stock, a quick Google search says this is normal. Hell on one site some one asked if the poster had ever fired a M16/AR15 as that is normal. Call me stupid but in my 23 years in the Air Force having to qualify on the M16, I never once felt a vibration in any M16 I shot.

So is this normal or not?
Is there a way to fix this?
What should I look at as the culprit?

Other than the vibration driving me nuts, fun was had by all, took out the AR15A2, AR15M4, M91, M91/30, M44, MAS36, and No4 Mk1. My nine year old GD fired her first real rifle today, my son's AR15M4 and my AR15A2, she liked the A2 the best.

All of them I have ever shot kind of go SPROING, when shot. It is that spring in the ass end of it. Perhaps that is causing the vibration.

Sounds like the ones I have fired, I don't have extensive experience with these but I found them noisy and rattily, then again I am a vintage bolt action guy. You do have that big recoil spring inside the buttstock, is the tube loose or damaged in some way?

Normal. It's the buffer spring inside of the receiver extension doing it's job.

My oldest son who just punched from the USMC, and is staying with us with his family, made an interesting observation. In the AF you use training rifles, how many thousands of rounds have gone through them, they are most likely worn out to a point, hence no sound. He was a firearms coach during his I&I tour and stated every M16 they had made that noise some worse than others.

I fired the first shot and thought damn something is loose or broken! After that I found myself anticipating the vibration, versus concentrating on my sight picture.

If you ever need to use that rifle for real you will not notice that irritating sound at all.

Did they take the Atchisson devices out of the ones you shot in the AF?

Seriously, they should be tight. You will hear the spring, until you replace it with a flat wound spring. Check the "castle nut" (Stock lock ring ) on the buttstock, and tighten it down.

I took the buffer and spring out to check them. Spring measured out at 12 3/4 inches. The buffer when you shake it makes a sound between a can of spray paint or a paint pen. Don't know what would be concidered normal in the noise range.

That's normal. If it worries you Midway and Brownell's sell buffers of many types. As long as you have it out, a flat wound spring is a worthwhile investment.

All of my buffers, including my Colt and BCM "H" buffers rattle. It's normal.

RazorBurn wrote:All of my buffers, including my Colt and BCM "H" buffers rattle. It's normal.

That's what everyone keeps telling me, I just never heard it/felt it when shooting the M16 in the AF. Retired in 2008 and I think I last fired the M16 in 2006.

The noise, vibration was so noticeable it caught me by surprise. Best way to describe it is to take a fiberglass pole and hold it straight out in front of you, then have someone hit the end of it. That wobble is what it felt like, with the spring noise.

How is the upper to lower fit? I have seen this be pretty loose on some rifles. That might cause said wiggle. I put one of those rubber spacers in mine and the upper to leer fit is quite tight now.

millman wrote:How is the upper to lower fit? I have seen this be pretty loose on some rifles. That might cause said wiggle. I put one of those rubber spacers in mine and the upper to leer fit is quite tight now.

Pretty tight fit, can't wobble it by hand, tighter than ones I shot in the AF that is for sure.

ffuries wrote:

RazorBurn wrote:All of my buffers, including my Colt and BCM "H" buffers rattle. It's normal.

That's what everyone keeps telling me, I just never heard it/felt it when shooting the M16 in the AF. Retired in 2008 and I think I last fired the M16 in 2006.

The noise, vibration was so noticeable it caught me by surprise. Best way to describe it is to take a fiberglass pole and hold it straight out in front of you, then have someone hit the end of it. That wobble is what it felt like, with the spring noise.

That's why I (jokingly) mentioned the Atchisson Device. The Air Force has used them for Basic Training and qualifications. (so I've heard from several AF vets.) You wouldn't hear the spring shucking up and down the buffer tube with the Atchisson Device, because it has an internal recoil spring. How do I know this? Because Army ROTC used them also. First time I shot an M16(A1) was with .22's! And I got stuck cleaning them because I "liked guns". Also how I ended up being the defacto ROTC Det. Armorer, and got stuck cleaning the 16's and 60's when we went camping er, on FTX's.

entropy wrote:

ffuries wrote:

RazorBurn wrote:All of my buffers, including my Colt and BCM "H" buffers rattle. It's normal.

That's what everyone keeps telling me, I just never heard it/felt it when shooting the M16 in the AF. Retired in 2008 and I think I last fired the M16 in 2006.

The noise, vibration was so noticeable it caught me by surprise. Best way to describe it is to take a fiberglass pole and hold it straight out in front of you, then have someone hit the end of it. That wobble is what it felt like, with the spring noise.

That's why I (jokingly) mentioned the Atchisson Device. The Air Force has used them for Basic Training and qualifications. (so I've heard from several AF vets.) You wouldn't hear the spring shucking up and down the buffer tube with the Atchisson Device, because it has an internal recoil spring. How do I know this? Because Army ROTC used them also. First time I shot an M16(A1) was with .22's! And I got stuck cleaning them because I "liked guns". Also how I ended up being the defacto ROTC Det. Armorer, and got stuck cleaning the 16's and 60's when we went camping er, on FTX's.

In Basic and my first unit we used the Atchisson Device, after that for the next 20 years it was with real 5.56 ammo.

The Atchisson Device jammed almost every other round, that thing sucked, that and there was a metal and canvas thing we put over the ejection port to deflect the 22 shells.

They worked great in full auto, but yeah, jammed in semi regularly. we left the feed bags off 'em, we were shooting in the basement range of the Armory, and just swept them up.

I bought one from Sarco back around '93, the miserable bastards never mentioned any of the devices shortcomings and that was before there was an internet to warn me. I unloaded that piece of shit fifteen years ago and at least made a small profit on it. Wouldn't work unless I soaked it in oil.

Junk Yard Dog wrote:I bought one from Sarco back around '93, the miserable bastards never mentioned any of the devices shortcomings and that was before there was an internet to warn me. I unloaded that piece of shit fifteen years ago and at least made a small profit on it. Wouldn't work unless I soaked it in oil.

Made it hard to shoot expert when your rifle jams after every shot. I hated that thing with a passion.

entropy wrote:They worked great in full auto, but yeah, jammed in semi regularly. we left the feed bags off 'em, we were shooting in the basement range of the Armory, and just swept them up.

So they were brass catchers, I thought they were deflectors. After 2 1/2 years of using the damn thing, I got stationed in Germany. First time I went to shot there I was in awe of shooting real 5.56 versus 22 ammo in the M16, the instructors laughed at my childless excitement. Never used it again and never had a desire to use it again.

It was a good ideal on paper, but a disaster in reality. I really have to wonder if the system ever worked correctly, or did it suck right out of the box?

JP Enterprises makes a self contained buffer system that gets rid of the feedback inside the tube... they include a spacer to work in rifle length tubes, and it allows you to remove the buffer retainer. Expensive, though. If I remember correctly, JP puts out a kit to adjust the spring tension/buffer weight).

I run it in my regularly shot AR, being I got it for a low price when it was released (wanted to try it out). Solves the feedback, especially with a .22 upper installed. But if you are paying full price for the kit, I'd have to say only do it if you really can't stand the noise. With the other three ARs I've built (one .45 D/I, one FDE 18", and I have a partially built lower that I'll finish when I leave NJ), all other ones use the standard buffer and spring. If it were cheaper, I may have tossed them in other rifles.