cant clear round out of ar-15

Munson

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We reload all of our rounds on a dillon 650. Cases are trimmed on a Giraud trimmer. Brass is a mix of mostly military range pick up that we swagged and whatever else is sitting on the ground when we sometimes shoot at civilian ranges. We are not that picky since we are mostly shooting inside 100yds and are looking for combat accurate. None of our shooting is done from a bench. Anyway, here is our problem. We are unable to manually clear a round from the chamber. You have to pound the stock on the ground while holding back pressure on the charging handle. After pounding it a few times it clears. It goes into battery fine both when shooting or when inserting in a new magazine both using the ping pong. It will eject cases fine when shooting. But when you need to "unload and show clear", you cant. Now this only occurs on our newer ar-15's. When we shoot the full auto M-16's, we dont have this problem. We have even picked the rounds off the ground once we beat them into submission and checked them on a case guage right there on the spot and they are showing right on the money. It is obviously a sizing issue, but its checks fine on the case guage. I have no idea what to do. Any help would be appreciated.
 

scotharr

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Re: cant clear round out of ar-15

What are the chamber dimensions? NATO or something tighter? Are you using a small base die. You never know what you are going to get at the range and a small base die is the safe bet to get the brass to fit into a different chamber. The final thing I'd suggest is checking the headspace on fired brass from your AR-15s and comparing it to the headspace on your resized range brass: need to have .002 minimum with .003-.004 being better for hassle-free chambering. Bottom line is you need to take a lot of measurements and you don't mention doing so above.
 

Munson

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Re: cant clear round out of ar-15

The chamber is from a CMMG barrel with appx 1500 rounds through it.

I have a small base die that I was going to try using and will get it set up next week and can report back. I was told though that the small base dies are kinda gimmicky. You are taking a cartridge and shrinking it below speck. The question was posed to me this way..."does that sound like a good idea?" Im not saying yes or no, just reporting what was said. Maybe a good discussion point since everyone is using them now.

I will measure the headspace and now that you mention it, I probably should have started there. Thanks for the help.
 

mtrmn

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    Re: cant clear round out of ar-15

    I use the RCBS small base X dies to prevent such as this and have no problems, but I can't sit here and tell you for certain small base dies will fix it. I also use the JP case gages. They are shaped like a chamber and check ALL dimensions instead of headspace at 1 certain point. Most case gages are not really a "chamber checker", I found this out AFTER I bought other brands and then had to go to the JP. I run each round thru the JP gage after a loading session just to eliminate that little doubt in my mind. Of course no 2 chambers are the same and YMMV.
     

    MALLARD

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    Re: cant clear round out of ar-15

    ya , try your small base die , i had the same issues not being able to clear loaded ammo from my AR's. ( but not in my HBAR , only the other ar's)
     

    scotharr

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    Re: cant clear round out of ar-15

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Munson</div><div class="ubbcode-body">The chamber is from a CMMG barrel with appx 1500 rounds through it.

    I have a small base die that I was going to try using and will get it set up next week and can report back. I was told though that the small base dies are kinda gimmicky. You are taking a cartridge and shrinking it below speck. The question was posed to me this way..."does that sound like a good idea?" ...</div></div>

    -Small Base F/L Die= returns brass to factory new dimensions (yep, sounds like a good idea for brass from unknown guns)
    Standard F/L Die= Returns brass about 1/2 way between new brass and fired brass dimensions....at least that's the intent.

    Remember with either die, you still need to set the headspace correctly. To be safe, you can set this to factory new dimensions also...you will need to measure.

    You don't want to use a small base die unless you have to because you are working the brass more than a standard die. In your situation, you are using brass that comes from unknown chambers...some may be quite cavernous. So, a small base die is the way to go for the 1st sizing. Once you have fired-formed it to your own rifle's chamber, you may find a standard full-length die works fine....just gotta resize it that first time all the way back down. If you consistently need to use a small base die, then your chamber is definitely tight(not NATO or Wylde).
     

    gunsnjeeps

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    Re: cant clear round out of ar-15

    Try chambering a sized piece of brass. Is your sizing die contacting your case holder? If the case is sticking and you are not in contact with the case holder then try turning the sizing die down half a turn more. Could be a tight chamber, could be an oversize die.
     

    bigwheeler

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    Re: cant clear round out of ar-15

    Is there land marks on the bullets of the stuck cleared rounds? Doesn't sound like
    the case to me if it fits the case gauge. Just sticking the bullet in the lands.
     

    Munson

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    Re: cant clear round out of ar-15

    well correct me if I am wrong, its happened...but if it checks out in a case gauge, then the headspace is correct...correct?
     

    mtrmn

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    Re: cant clear round out of ar-15

    Most case gauges for bottleneck cartridges are NOT shaped like your chamber. I don't know which brand gauge you have, but the only brand I'm SURE are actually cut with chamber reamers is JP. I bought my gauges from Brownell's. I had been using Lyman gages until I found out they really did NOT check ALL chamber dimensions.

    http://www.jprifles.com/1.5.1.2_maint.php
     

    FLIGHT762

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    Re: cant clear round out of ar-15

    Every time I've had the issues you described, The F/L die needed to be turned in a bit more into the press, bumping the shoulder back a couple more thousandths.

    Using a shoulder bump gauge with a set of digital calipers gives you numbers you can see. A bit more precise than a drop in case gauge.
     

    rpk762

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    Re: cant clear round out of ar-15

    Like the others have said more than likely the small base will fix it for you. Your chamber is probably a little more snug than the rest of your rifles. There are things you can check like how much bump you are giving the shoulder but your case head junction sounds like it is not getting enough sizing. Measure a fired then resized casing. Then put it in the rifle and see if you can pull it out. Wipe off the oil first.
     

    Smith44699

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    Re: cant clear round out of ar-15

    Set of dillon dies. Which are small base. Headspace Gauge to set the die up. It will solve your problems. IMO
     

    MaximumVelocity

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    Re: cant clear round out of ar-15

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bigwheeler</div><div class="ubbcode-body"> Is there land marks on the bullets of the stuck cleared rounds? Doesn't sound like
    the case to me if it fits the case gauge. Just sticking the bullet in the lands. </div></div>

    ^^^

    This...

    I've had this problem several times. If the bullet is contacting the lands, it will be hard to pull out. Once you get the bullet out, look at it around the mouth. If you see land marks then your bullet needs to be seated deeper.

    Try some different ammo with a lower grain bullet and just see if it will cycle through the gun manually.