Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
BCM
User Panel

Page AR-15 » AR Pistols
AR Sponsor: bravocompany
Posted: 3/23/2017 6:47:26 PM EDT
Did first AR Pistol build and went to the range and had problems with duds ( primer dimpled but no fire) probably 8 times out of 70 rounds also the bolt never locked back after the mag was empty.  Any help would be appreciated.  Here is the config:  Radical Firearms 7.5" 5.56 1/7" Twist Upper w/ Round Rail , Primary Arms CQB muzzle compensator ( in place of Birdcage it came with Muzzle, SAA - AR-15/M16 Nickel Boron M16 Style ENHANCED M16 Style Bolt Carrier Group, Raptor Charging handle, KAK Super Sig SB15 Buffer Tube kit, KAK Lower parts kit, and a Ruger roll mark lower.  When it did fire it had very little recoil. Thanks in advance
Link Posted: 3/23/2017 6:51:27 PM EDT
[#1]
What ammo?
Link Posted: 3/23/2017 7:22:54 PM EDT
[#2]
What trigger?  Low power springs?
Link Posted: 3/23/2017 7:38:14 PM EDT
[#3]
Have you checked your firing pin?
Link Posted: 3/23/2017 8:14:21 PM EDT
[#4]
 Is it under gassed?

If your gas block is not adjustable, are the ports in the barrel and gas block lined up properly?

 If adjustable, give it more gas.

Sounds like the bolt carrier may be not going back far enough to lock back on mag and also not returning hard enough to fully seat allowing the firing pin to barely reach the round.   Could explain the perceived low recoil as well. 
Link Posted: 3/23/2017 9:33:09 PM EDT
[#5]
20 rounds were American Eagle 5.56 62 Grain FMJ and 50 were Freedom Munitions 223 Remington 55 Gr FMJ. Also to note that the shells were being ejected forward at 1 o'clock
Link Posted: 3/23/2017 9:34:10 PM EDT
[#6]
Trigger is KAK LPK I believe its the standard base Mil spec
Link Posted: 3/23/2017 9:34:43 PM EDT
[#7]
Firing pin seemed fine
Link Posted: 3/23/2017 9:39:37 PM EDT
[#8]
Due to the fact that the rounds are shooting out at 1'clock I believe it may be over gassed.  And maybe getting a little bounce and not fully seated.  The last round stuck in the chamber and had to be rodded to get out.  Its a factory complete upper from Radical firearms non adjustable.
Link Posted: 3/23/2017 10:37:38 PM EDT
[#9]
Turns out I had the hammer spring upside down. Will test at range tomorrow. Thanks all.
Link Posted: 3/25/2017 12:56:11 AM EDT
[#10]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Turns out I had the hammer spring upside down. Will test at range tomorrow. Thanks all.
View Quote
Shit happens.  Glad you found the light strike problem.  

Make sure your extractor spring has enough tension and has an o-ring on it for extra tension.  I replaced my original spring and bumper (had no o-ring) with a BCM extra power kit which has a higher tension spring, bumper and o-ring.  Might help your extractor slipping over the case head problem.
Page AR-15 » AR Pistols
AR Sponsor: bravocompany
Close Join Our Mail List to Stay Up To Date! Win a FREE Membership!

Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!

You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.


By signing up you agree to our User Agreement. *Must have a registered ARFCOM account to win.
Top Top