Thursday, December 20, 2018

Correction on DPMS post

The two rounds that failed to feed. Would it be accurate to call those "hickies below the neck" since the marks were made by the lips of the magazine?

My friend informed me that what we tested was not "bone-stock".

The Oracle came from the factory with a 30 round, polymer magazine PMAG 30.

We tested the Oracle with a ten round, C Products Defense steel magazine.

Playing with the follower, the PMAG has better anti-tilt and the lips of the magazine are not as sharp as the C Products. My expectation is that the PMAG will feed better at lower bolt return-to-battery speeds.

While that information invalidates the data it confirms the hypothesis that changing your AR can reduce its reliability.

The sweep will be repeated in the near future with the factory supplied magazines.


  1. 'Most' FTFs are caused by magazine issues... sigh... Feed lips, spring tension, tilt issues, loose lock in, etc.

  2. It's an interesting hypothesis, to wit: "...changing your AR can reduce its reliability." If I captured your hypothesis accurately I'm going to say "poppycock". It's a weak hypothesis; for no other reason than one could just as easily postulate, and prove, that modifying an AR can improve its reliability. If one takes the time to learn about how the weapon functions, learns about the components and their manufacture, and understands the specifications of the design, you can easily deviate your modifications towards either end of the performance and reliability spectrum.

    1. Either hypothesis remains a hypothesis until there is data. That is what I am trying to do: Generate meaningful data.

  3. Just an FYI if you're looking to pick up a AR15. I go to a lot of gun auctions in our area and lately brand new and near new AR's are going out the door for $400 or less, just like this DPMS a couple of weeks ago:
    I'd say the market has been saturated.

    1. Dunhams Sports is frequently running a base 5.56 AR at the $399 price point.

      Thanks for the info.

  4. Often, I am told, replacing the follower and/or the springs in a magazine with good quality ones will improve reliability. Those 10's and 20's are easier to shoot prone with too :) A quick check at MidwayUSA shows a 3-pack of Magpul anti-tilt followers for $6.00, and Wolff 20- or 30-round magazine springs at $18 for a 3-pack.

    Just a thought.


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