I've now seen this problem three times at shoots, twice this weekend, and wondered if others have also seen or diagnosed it:
With the magazine in place, the bolt release binds up and is unable to release / is even more difficult than usual to release. In the worst case, the mag is also unable to be released and has to be assisted by wiggling the release level / pressure from the top.
In all three cases, the mag release lever was polymer material. Since the pivot pin is steel, my guess is that the release wears unevenly against that pin when the lever is repeatedly hit hard and off center (as in shooting an AQT). Eventually the body of the mag release begins to bind against the bolt release plate, causing jams in one or both releases. Probable fix is to get a metal mag release.
Anyone else seeing this? Does your diagnosis agree?
Out of curiosity, have these been modded for auto bolt release?
Quote from: Langer on February 21, 2012, 12:54:39 AM
Out of curiosity, have these been modded for auto bolt release?
I believe they all had the stock bolt release. Two of the polymer mag releases were Ruger, and one was aftermarket. The aftermarket release was softer plastic, and was visibly worn when we disassembled it.
Check the magazine bolt is tight. If the bolt loosens it becomes impossible to get the mag to drop. Put a knife blade up and push the end of the mag back flush and the mag will drop. Especially if someones been disassembling the mag to tighten the spring or clean.
Quote from: V on February 21, 2012, 01:45:20 AM
Check the magazine bolt is tight. If the bolt loosens it becomes impossible to get the mag to drop. Put a knife blade up and push the end of the mag back flush and the mag will drop. Especially if someones been disassembling the mag to tighten the spring or clean.
Yup, I know that problem. (Don't ask how... :-[) We tried multiple mags in each of these cases to make sure that wasn't the issue - it was not.
I do not recall seeing the problem your post refers to.
After you replace the worn parts , please keep us informed . If that was the fix .
Eventually we all may see this problem showing up , be nice to have a spare part or so.
thanx for all who offered solutions and for bringing this to our attention.
+1 to what V said. On one occasion, someone had replaced the bolt with a Phillips head screw. Don't ask me why!
Never seen this. Will be on the lookout. Always remember, to lock push back, to release push up.
Quote from: Johnnyappleseed on February 21, 2012, 02:22:03 AM
After you replace the worn parts , please keep us informed . If that was the fix .
Two of the failed rifles belong to IITs (the other failure was down in SLO), so I'll hear how the tear-down and repair go.
The verdicts are in, and though the malfs mentioned had very similar symptoms they were from - three different causes!
One was in fact an aftermarket bolt release extension, made from polymer that was wearing after heavy use and causing binding.
The second was exactly as Phil described - the bolt in the rotary mag backing out, binding up the mag release. Apparently it was 1/8" out of position before things completely jammed, and the shooter's other mag was on the way to the same failure.
In the third case the rifle had been reassembled after a take down omitting the bolt buffer, and resulting vibration rattled the pins in the trigger assembly far enough out of place to cause parts to bind up.
So -
Don't buy cheap aftermarket parts
Check the mag bolts at the same time as you check the take down screw and sights
and make sure there aren't any parts left over. ;D