Questions and Problems!!

AR/M4 AR Technical Discussion
1

Well I finally got my first AR-15 rifle and took it to the range yesterday (see post in general discussion for details of some great people CombatVet and I met)! I had some questions and problems. My rifle has a DPMS Lower and a flat top M4 style Upper. Barrel is marked DTI 5.56 NATO 1-9. My front sight is a Young MFG (the sight looks just like the one Les Baer sells in fact according to another forum Young MFG makes Les Baer their sights). The rear flip sight looks like the Knights Armament 300m sight BUT it has a “switch” on the left side with adjustments from 200-600m. I should say I’ve looked at Knights Armory site and I can’t find this sight, perhaps it’s an older one? My questions and problems are:

  1. My rifle had 4 failure to feed moments both of which were attributed to faulty mags. Both were “new” and the follower wouldn’t rise on one of them. Is this normal for “new” mags?
  2. I had SEVERAL light primer strikes! CombatVet and I replaced the firing pin, the buffer AND spring and not only did the problem NOT stop, it got worse! I had to eject 7 rounds from my last 30 round mag. Is this problem “short stroking”?
  3. Could the front sight gas system be causing the problem? ie “leaking”?
  4. Has anybody had experinnce with the Young front flip sight?
  5. Does/Did Knight’s Armament ever make a rear flip sight like the one I described (this better NOT be AirSoft!):mad:

Thanks for your attention in advance!

2
  1. Not normal.
  2. Make sure each of the hammer spring legs are sitting on top of the trigger pin in the lower.
  3. Maybe, if the bolt doesn’t lock back when the rifle runs dry, then most likely you do have a gas leak somewhere.
  4. No.
  5. I think you may have a MATECH rear sight, if it looks something like the one below. Too much shit to break on those for this Chairborne Ranger.

3

I’m thinking gas tube issues due to an inexperienced person installing the FSB and crimping the tube.

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Not the best pic, but this gives you an idea.

5

Indeed I have a Matech rear sight! I had to “bottom out” my front sight just to sight the rifle in at 25 yards! Anybody have opinions or better yet experience with these sights?

Eric, you’re my hero! Absolutley the hammer spring has both of it’s “legs” resting on the trigger bar buuuut it’s upside down! I’m gonna switch it out right now and will try the rifle again this weekend!

Thanks to all who responded!

6

Another M4Carbine happy ending. :wink: