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10/11/2004 4:01:05 PM EDT
my bolt will not lock open when the gun shoots a mag dry.  i tried cleaning it and oiling it w/ no change.  it just started happening one day.  it has happened w/ 5 different mags over 200 rnds.  it happens every time.  but other than that problem, the gun still shoots great.  

anyone have any suggestions?  i did a search and looked in the faqs w/out success.  thanks
10/11/2004 6:47:53 PM EDT
[#1]
Check the screws holding the key on the carrier.  Some times the staking will hold a broken screw head.   Get an allen wrench in there and make sure they are still tight.
10/11/2004 7:58:23 PM EDT
[#2]
What ammo are you using ?  If it is under-powered ammo, it will not properly cycle the action.  If you reload and use too fast powder, it will short stroke also.
10/12/2004 4:30:52 AM EDT
[#3]
oldguy,
the key is the tube where the gas tube goes, right?  there are 2 hex head screws holding that down and they are very tight.  i could not even move them.  the do not look cracked.

G35,
i'm using the same ammo i have always been using: new wolf polymer 55gr. FMJ and federal LC XM193 55gr.  i have shot thousands of both these brands w/ no problems beore.

the only thing i do notice is that there is a slight burr on the top of the bolt catch in side the gun.  could this be the problem?  it's a very small scratch.

any other suggestions?
10/12/2004 4:45:29 PM EDT
[#4]
Try cleaning your gas tube...
10/13/2004 9:06:57 AM EDT
[#5]
Mag spring fatigue?

10/13/2004 11:02:19 AM EDT
[#6]
gas tube is fine.  i doubt it is short stroking b/c there have been no other failures in 300 rounds.

this is happening w/ 6 different mags - 3 labelle 30rnd green followers, 2 colt 20rnd, and 1 british 30rnd steel mag.
10/13/2004 11:46:12 AM EDT
[#7]
Does the bolt catch function with a empty mag with the upper off the lower? Can you lock the bolt back manually with the rifle assembled?
10/13/2004 11:54:55 AM EDT
[#8]
I'm watching this thread closely in that I'm having the same problem.  Tweak, I can manually lock the bolt back with the upper and lower assembled.  Oldguy, the screws in the key are tight, but had recently worked loose, causing shortstroking.  It's happening with all my mags, and happens often when cycling the bolt by hand on an empty mag.
10/13/2004 11:58:31 AM EDT
[#9]
i can also manually lock the bolt back w/ the gun assembled.  i'll try it disassembled when i get home tonight.

it also manually locks back w/ an empty mag inserted.
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