Page 1 of 2 12 LastLast
Results 1 to 10 of 17

Thread: Misfire central...Check out the dents on this brass

  1. #1
    Join Date
    Oct 2007
    Posts
    62
    Feedback Score
    13 (93%)

    Misfire central...Check out the dents on this brass

    Factory new Rifle, cleaned, well lubed, gas key tight/staked, gas block tight/straight/pinned, barrel, barrel nut and rail all appears to be properly installed and tight. Took it to the range for a BZO, fired around 35-40rds, accuracy compared to my norm was disappointing, overall extraction was pretty weak with intermittent FTE's, stovepipes, one double feed. Ammo was 2011 Winchester RANGER M855 (all of my other 556 AR's love it), mags used were known good magazines both USGI and PMAGS. I've never experienced any problems with a AR-15 like this before. Always used high quality weapons, parts etc and good quality ammo and mags. Looking at the brass it seems that there is something in the chamber that is denting/gouging into the brass and causing the extraction problems. The flash is drowning, but there are also scratches down the length of the brass on the same side as the dents and some gouging on the case rim from the extractor having to work hard.

    What do you malfunction guru's think is going on. Chamber out of spec?








  2. #2
    Join Date
    Dec 2009
    Location
    Utah
    Posts
    8,422
    Feedback Score
    3 (100%)
    Those marks are not coming from something in the chamber. Something in the chamber leaving that much of a dent would have the brass sticking. They are getting there during extraction and/or ejection. If the brass were being dented prior to being fed into the chamber, the pressure from firing would push them back out
    INSIDE PLAN OF BOX
    1. ROAD-RUNNER LIFTS GLASS OF WATER- PULLING UP MATCH
    2. MATCH SCRATCHES ON MATCH-BOX
    3. MATCH LIGHTS FUSE TO TNT
    4. BOOM!
    5. HA-HA!!

    -WILE E. COYOTE, AUTHOR OF "EVERYTHING I NEEDED TO KNOW IN LIFE, I LEARNED FROM GOLDBERG & MURPHY"

    http://i115.photobucket.com/albums/n289/SgtSongDog/AR%20Carbine/DSC_0114.jpg
    I am American

  3. #3
    Join Date
    Oct 2007
    Posts
    62
    Feedback Score
    13 (93%)
    Quote Originally Posted by MistWolf View Post
    Those marks are not coming from something in the chamber. Something in the chamber leaving that much of a dent would have the brass sticking. They are getting there during extraction and/or ejection. If the brass were being dented prior to being fed into the chamber, the pressure from firing would push them back out
    Not sure what it could be hitting that would make the mark. Maybe the rear of the ejection port due to a weak ejector? The marks are def NOT there prior to firing.

  4. #4
    Join Date
    Dec 2012
    Location
    NW WA
    Posts
    346
    Feedback Score
    1 (100%)
    For troubleshooting what position does the brass eject? Are you sure the dents aren't from the brass deflector? Whats the run down on the rifle?

  5. #5
    Join Date
    Aug 2011
    Posts
    63
    Feedback Score
    2 (100%)
    What happens when you chamber a round and then eject it without firing?
    Silence can not be misquoted!

  6. #6
    Join Date
    Oct 2007
    Posts
    62
    Feedback Score
    13 (93%)
    Quote Originally Posted by armed_zebra View Post
    What happens when you chamber a round and then eject it without firing?
    I manually chambered and ejected rounds from the chamber on two or three occasions prior to pulling the bcg and checking the barrel for obstructions after several FTE's/Stove pipes. The rounds ejected no different than expected with a properly functioning AR. That is what prompted me to take a look at the fired brass.

    In all of my years of shooting I've never seen mil brass hit a shell deflector so hard it dented it. If that was the case it would be extremely violent overpressure type extraction, not weak extraction right?

  7. #7
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,902
    Feedback Score
    104 (100%)
    Can you please provide more details about the AR in question.

    You may also want to check this- http://www.winchester.com/library/ne...56mm-m855.aspx



    Owner/Instructor at Semper Paratus Arms

    Facebook: https://www.facebook.com/SemperParatusArms/

    Semper Paratus Arms AR15 Armorer Course http://www.semperparatusarms.com/cou...-registration/

    M4C Misc. Training and Course Announcements- http://www.m4carbine.net/forumdisplay.php?f=141

    Master Armorer/R&D at SIONICS Weapon Systems- http://sionicsweaponsystems.com

  8. #8
    Join Date
    Apr 2009
    Location
    Wisconsin
    Posts
    2,908
    Feedback Score
    8 (100%)
    The failures to extract, (eject? Which one is it? FTE can mean either), and stovepipe are a gas/action issue.
    Check for gas leaks and check your buffer spring buffer combo.

    The double feed is a magazine issue.
    Quote Originally Posted by scottryan View Post
    Anybody that owns or sells pistol versions of assault rifles is a bottom feeder, irregardless of the ban status of certain ammunition.

    They are illigetimate weapons that have no real purpose other than to attract retards to the gun community.

  9. #9
    Join Date
    Oct 2011
    Location
    Alaska
    Posts
    3,523
    Feedback Score
    3 (100%)
    The swipes on the base of the brass, combined with the dents mid-length down the brass from the brass deflector, are both signs of over pressure.

    How does it perform with other ammo?

  10. #10
    Join Date
    Oct 2007
    Posts
    62
    Feedback Score
    13 (93%)
    Quote Originally Posted by Iraqgunz View Post
    Can you please provide more details about the AR in question.

    You may also want to check this- http://www.winchester.com/library/ne...56mm-m855.aspx
    Thank you for that link. I can certainly check more closely tomorrow, however the ammo I'm using is stamped 2011, from the RANGER LE line RAM855, in RANGER packaging 1000rds per case (not the brown box 900rd cases as listed) and I've fired hundreds of rounds from the same case through my other AR's without a hitch.

    The weapon I experienced this with is a new KAC SR-15E3 Mod 1. I've owned several SR's in the past...from SR-15 Matches to the 1st Gen E3's and they all performed extremely well with above average accuracy. This shocked me, mostly because I've had next to zero malfunctions with the AR platform in 20 years of running them. This just stumped me as to what the cause could be. Top shelf weapon, good mags, good ammo etc. That's why I decided to post up here and see if it was something blatantly obvious that I was simply ignorant about.

    Thanks gent's.

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •