The Creedmoor Forum

6mm-creedmoor AR Feeding Issues

December 06, 2018, 02:42:34 PM

Hello everyone. I am new to the forum and would like some advice on some problems I'm having with my build.

  Barrel - Odin Works 6mm Creedmoor
  Upper Receiver - Aero Precision M5 Upper
  Bolt/Bolt Carrier - Brownells
  Lower - 5dtactical 80%
  Stock/Buffer - Dpms Rifle Buffer(tube,spring,etc)
                            Magpul PRS Gen 3
  Parts Kit - DPMS
  Mags - PMags Gen 3
  Load - Sierra 107gr SMK, Hornady New Brass, 41 grains
              H4350, 2.800"

      The rifle is having trouble feeding from a magazine. If you can tell from the picture, the tip of the bullet is being fed directly into the rear of the barrel. Some of the rounds will fail to feed and others will glance off and chamber. The rounds that chamber have deformed tips and are set back in the case anywhere from .010" to .100"! NOT GOOD! (Running .003" neck tension). 
     On top of that, the bolt will also not hold open. The BCG will travel to the rear far enough but the bolt catch can not elevate high enough to reach the bolt face. I am wondering if the 80% lower is out of spec? The upper and lower fit pretty tight with each other. There is the slightest bit of light that can be seen through the upper and lower by the rear takedown pin. I'm thinking that the magazine catch and mag release might be improperly located in the lower?

     For what it's worth. I single fed around 20 rounds through the gun, and at 100 yards they were going through the same hole. Sorry for the dirty gun as I was shooting suppressed

 

Re: 6mm-creedmoor AR Feeding Issues

Reply #1 – December 07, 2018, 10:15:51 AM

Hey,
Welcome to the forum!  Three things pop up to my mind on your build. First is the feeding issue, most likely it is the 80% lower out of spec. I’ve had this issue before and swapping it for an Aero M5 lower receiver did the job. As far as the bolt catch, you could of accidentally received a rifle length 5.56 buffer which is a touch longer then the 308 variety but since you said the bolt travel is long enough I’m going to say it’s the bolt catch. With a M5 upper receiver you need an Aero Precision bolt catch to work. A DPMS bolt catch won’t have enough travel. I made that same errror but was easily corrected by ordering the AP bolt catch for M5 receivers.

Re: 6mm-creedmoor AR Feeding Issues

Reply #2 – December 07, 2018, 12:48:48 PM

Thanks for the reply and welcoming to the forum!
   
     I called 5dtactical yesterday and they said I would be called back when someone who is knowledgeable gets off lunch. I called them at 2:30pm... Suprise, surprise, I never heard back since. I'm glad your same problem was fixed with the M5 lower because I ordered one last night! I bought a complete lower so obviously it will be with their parts kit.
     I've built over a dozen AR15s and I thought this would go easy Haha!
     I will post some pictures and groups when everything comes in.

Re: 6mm-creedmoor AR Feeding Issues

Reply #3 – December 08, 2018, 02:50:43 PM

Had the same problem with my 6.5 creedmoor  . Vld type bullets go through the teeth of the barrel extension instead of up the ramps .My solution was use bullets with a fatter nose profile.

Re: 6mm-creedmoor AR Feeding Issues

Reply #4 – December 08, 2018, 03:50:06 PM

I’d be suspicious of the 80% lower