Issue with new build

ACC

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Put together another AR15. It is for some precision fun. Freefloat 18" 1-7 midlength gas system barrel with Surefire Brake, PWS stock with rifle buffer and spring. Geiselle SSE trigger. Was shooting some 77gr SMK the other day and it was a clover leaf at 100m. Everything is good that way for starting out, however it seems like there is some vibrations going on with the barrel or it might just be the buffer. Can't tell? The buffer is definitely different and you can hear the spring working. Anyone run into this happening before?
 

harbinger

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You can hear the buffer spring on most AR's when they are cycling if you listen for it, some are louder that others. Putting a new one together for my brother in law and when the buffer came in it rattles like crazy. Sounds like the weights inside are loose, maybe check there. Also if there is any grit in the buffer tube it will make the spring sound worse, just a couple of thoughts.
 

ORD

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Yup...the buffer spring "twang" and similar noises erupting from the rifle when it cycles is par for the course.

You can minimize the noise to a certain degree with an adjustable gas block to tune the amount of gas you are feeding back into the action, with an XP buffer spring, a heavier buffer (or one that doesn't use the traditional "sliding" buffer weights), bolt carrier weight, the stupid "Twang Buster" devices made to "deal" with the problem (which I generally wouldn't recommend as they don't really work by in large), etc.

As the old saying goes: If it ain't broke...DON'T FIX IT!! If the rifle is shooting that well, learn to live with the noise and leave well enough alone unless it really bothers you that much, then you can try any (or all) of the above, but again...its the nature of the beast to a certain extent.
 

BigtimeAub

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Before trying to blame the buffer or any other components for a clover leaf at 100m, I'd be more interested in knowing exactly just how much load development you've done for the rifle. Were you shooting factory loads, hand loads? There are many, many variables that come into play when "precision" shooting when it comes to just the load itself. Last summer I sold my F T/R bolt rifle that would put 5 rounds through 1 clean round hole at 100 yards with the load I had found for it but if I just changed even one variable in that load it would shoot all sorts of different patterns. It could be possible that your barrel doesn't like the 77gr SMK's. Just because you have a higher twist rate doesn't necessarily mean that your barrel will shoot them optimally in regards to POI, it just means that it can spin them fast enough to stabilize the much heavier round. In addition to the weight of the bullet, the powder or the primer could be a problem. If your powder has too high or too low of a burn rate, you may not be optimizing the potential of the powder. If it's too low, you could possibly only be using a partial amount of the powder as you would be blowing unspent powder out of the end of the barrel. If it's too high, you could be burning the powder too fast and not getting an even burn to keep the pressures high throughout the entire length of the barrel. If the primers aren't right, You could possibly be burning too much or too little powder upon primer strike. These are just a few of the issues to consider. The next thing, or possibly even the first thing that I would look at, is whether or not you're using a bipod, benchrest, bags, free hand, sled, prone, standing, sitting. When shooting "precision" any and/or all of these things can result in significant POI disparities. This is probably way too technical of a response in regards to what you were looking for but you did say that you're trying to do precision shooting. So in order to truly get precision results, everything you do up to that point must be precision oriented.
 
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ACC

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Sep 21, 2011
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Thanks. Have a few other ARs and none seems to have this rattle. I will leave it alone and live with it. Seems like it will be a good shooter.

Just saw the above post. No issue with the cloverleaf. The issue was the noise and vibration I think I am feeling. Yes, they are my first hand loads for this rifle. They were taken from a box of hand loads from another rifle I load for. Had to load one at a time because of COAL but I will shorten them to see if I can get good results and them to run in the mags.

So the question I was asking is just about vibration, not the precision portion of it.
 
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