Quantcast
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Sierra Match King in an AR - jamming

Discussion in 'Handloading and Reloading' started by BNAllen, Nov 30, 2009.

Thread Status:
Not open for further replies.
  1. BNAllen

    BNAllen Member

    Joined:
    Feb 21, 2009
    Messages:
    32
    I am hand-loading a 55 gr. Sierra BlitzKing for my AR 15. I have sized the case and the load according to my Sierra manual. The manual has a COAL of 2.250" and I have seated bullet a tad deeper to COAL of 2.200" (I did this as 55 gr. Remington FMJ factory loads ran great ... this is their COAL). My problem, the hand-load is picked up from the magazine but the bolt lacks closing by about an 1/8 of an inch. I am unable to assist the round (into battery) and the charging handle requires considerable effort to extract the case. I see no visible signs of problems on the case or the bullet. All I can determine is the action prefers the full metal jacket load versus the plastic tipped BlitKing. Anyone have experience with this issue? Thanks!
     
  2. NCMauser

    NCMauser Member

    Joined:
    Mar 8, 2008
    Messages:
    13
    BNAllen, Are you full length sizing? Are you using .223 or 5.56 brass. If you are using 5.56 and AR is chambered for .223 that is the problem.
     
  3. Byron

    Byron Member

    Joined:
    Jan 2, 2003
    Messages:
    1,027
    Location:
    TN
    Allen, I have used a RCBS small base dies for many years and do not have a problem. There should be no difference in military vs. commercial brass when run through the sizing die. That difference would be military ammo vs commercial ammo not the fired case.
    Have you been using Wolf that that coats the steel case? That could have caused some sticking. Give the chamber a thourgh cleaning using the chamber brush. Byron
     
  4. jim147

    jim147 Member

    Joined:
    Jul 11, 2008
    Messages:
    344
    Location:
    Western MO
    Take a black marker to the bullet and brass. Find out where your problem is.
    Can you load different bullets in the same brass without problems?
    Can you chamber the resized brass?

    Questions lead to questions which lead to answers that may lead to more questions.
    It can be a fun process.

    jim
     
  5. tlen

    tlen Member

    Joined:
    May 12, 2008
    Messages:
    526
    Location:
    Kansas
    Sounds like a sizing die adjustment issue.
    BTW, .223 Remington and 5.56X45mm NATO have the same external dimensions.
     
  6. counterclockwise

    counterclockwise Member

    Joined:
    Jan 17, 2008
    Messages:
    176
    There are many ways you can wind up with handloaded brass dimensions greater than Remington FMJ Factory load brass in the wrong places (and still have a smaller OAL).

    Seating force can be excessive causing bulging at the shoulder/body intersection.
    Trim length can be excessive causing case neck to jam into chamber relief.
    Resizing can cause case to grow lengthwise from shoulder to rim face.

    Your AR chamber is now acting as a case gage and rejecting your reloaded case.
     
  7. BNAllen

    BNAllen Member

    Joined:
    Feb 21, 2009
    Messages:
    32
    I will work up dummy loads with different bullets to see if they feed correctly. And, I will work up dummy loads with the BlitzKing bullets just to see how they seat into chamber. Thanks for the help ... Ill let you know what I learn ... maybe someone else will also benefit from my endeavors.
     
  8. BNAllen

    BNAllen Member

    Joined:
    Feb 21, 2009
    Messages:
    32
    Yes full-length resizing .223 cases
     
  9. Canuck-IL

    Canuck-IL Member

    Joined:
    Feb 15, 2005
    Messages:
    1,590
    As noted repeatedly above, it's not the bullets - it's the cases.

    Do you have the sizing die down far enough that the press 'cams over' at the top of the stroke? Put felt marker on some cases and hand cycle them ... also, brush out the chamber really well.
    /Bryan
     
  10. Historian

    Historian Member

    Joined:
    Oct 6, 2007
    Messages:
    328
    Location:
    Dallas, Texas
    It sounds to me like the sizing die is not fully sizing the cases. Make sure that you turn it down a quarter turn past the point where it engages the shell holder when the press is in the full up position.

    Historian
     
  11. rcmodel

    rcmodel Member in memoriam

    Joined:
    Sep 17, 2007
    Messages:
    59,082
    Location:
    Eastern KS
    Sound advice on the sizing die.
    Your press has to "bump" or cam over at full ram travel in order to get the case shoulder back where it came from.

    The other leading cause of your problem is excess crimp.

    Make sure your seating die is not screwed in so far as to crimp the case neck on the bullet.
    That will buckle the shoulder imperceptibly, but the rounds will not chamber.

    rc
     
  12. EddieNFL

    EddieNFL member

    Joined:
    Nov 9, 2009
    Messages:
    3,329
    I disagree. I've used headstamps from the 70's through '06 without issue in bolt and gas guns.

    This problem is usually due to insufficient shoulder setback. The best advice I ever got for sizing dies was to throw out the factory directions. You can use a tool that measures head space via a fired case. Set the die to reduce by .001" to .003" depending on application (I like .002" for semis). I use RCBS case mics. In a pinch you can use your chamber by turning in the size die until you get a case that will just barely chamber. Turn the die an additional 1/16 to 1/8 turn and you should be set. Good luck.

    EDITED BECAUSE I DIDN'T EDIT (thanks RC)
     
    Last edited: Dec 1, 2009
  13. rcmodel

    rcmodel Member in memoriam

    Joined:
    Sep 17, 2007
    Messages:
    59,082
    Location:
    Eastern KS
    Inch?

    Don't you mean an additional 1/16 to 1/8 turn? (.004 - .009")

    You most certainly do not want to screw the die in another 1/16" to 1/8" inch (.0625" - .125") after the case will just barely chamber.

    rc
     
  14. EddieNFL

    EddieNFL member

    Joined:
    Nov 9, 2009
    Messages:
    3,329
    Yes, I did mean turn. Good catch.
     
  15. JuryRig

    JuryRig Member

    Joined:
    Apr 25, 2006
    Messages:
    51
    Location:
    Eburg, WA
  16. tggdeer

    tggdeer Member

    Joined:
    Jan 7, 2009
    Messages:
    79
    Location:
    Georgia
    same problem

    I just had the same problem. I got advice from this forum anf fixed the problem. I had to screw the sizing die in another 1/8 of a turn, and that fixed the problem.
     
  17. BNAllen

    BNAllen Member

    Joined:
    Feb 21, 2009
    Messages:
    32
    Thanks everbody ... I am looking forward to hitting the bench tonight to see what happens. I'll post my findings!

    Regards, Brad
     
  18. redneckdan

    redneckdan Member

    Joined:
    Jul 2, 2006
    Messages:
    482
    Limit yourself to one variable at a time.

    First question, is this brass that has been fired in your chamber before? If so I would think it would be a crimping issue, ie cases too long or too heavy a crimp. Honestly you shouldn't need to crimp the rounds anyway....eliminate that variable for now.

    If this is brass not from your rifle, I would assume a sizing die issue. Work with just the sizing die until you are sure that the sized cases will chamber smoothly. It is possible that your dies are out of spec, I had a redding die that would not set the shoulder back far enough, solution was to face off the base of the die in a lathe. Also make sure your cases are well lubed. A lubed case will see the shoulder set back further than a case with insufficent lube, given the same die setting...this can be a significant ammount...upwards of .003" that I've personally measured.
     
  19. JoelSteinbach

    JoelSteinbach Member

    Joined:
    Dec 7, 2008
    Messages:
    477
    Location:
    TN from the Bronx NY
    been there done that, Trim, small base sizing die has solved my problems both with My AR and M1a
     
  20. W.E.G.

    W.E.G. Member

    Joined:
    Sep 26, 2006
    Messages:
    7,392
    Location:
    all over Virginia
    Measure or fail.

    [​IMG]
     
  21. redneckdan

    redneckdan Member

    Joined:
    Jul 2, 2006
    Messages:
    482
    For a quick and dirty measure of head space, make one of these...except for use as a head space gauge. Use something along the lines of a 3/4" nut, heat it up to soften it, drill, then heat and oil quench. http://www.sinclairintl.com/product/5582/Bullet-Comparators You want roughly .330" for the .223 Slip it over the shoulder and use your caliper to measure. Compare a case fired in your rifle with the cases you sized.
     
  22. Historian

    Historian Member

    Joined:
    Oct 6, 2007
    Messages:
    328
    Location:
    Dallas, Texas
    +1 for W.E.G. I have a head space micrometer and I use it whenever I size cases. It will tell you in a couple of seconds if your die is properly adjusted.

    Historian
     
  23. BNAllen

    BNAllen Member

    Joined:
    Feb 21, 2009
    Messages:
    32
    Update ... I've sized three fired cases making certain that the press noticeably cams over. I then seated three bullets. I placed the three dummy loads into the magazine and worked the action. All three went into battery and then ejected properly. I believe the problem was truly the sizing of the cases (as most pointed out) ...

    Thanks everyone!

    Brad
     
    Last edited: Dec 3, 2009
Thread Status:
Not open for further replies.

Share This Page