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12/23/2010 8:30:24 AM EDT
my m-261 bolt is recoiling to-far back  and locking back.
Replace Recoil Spring, using Federal Champion 22LR. , Break Free lube,  I can't see any other problem with it.
Any thought's?

12/23/2010 9:10:49 AM EDT
[#1]
what's it locking back on? pics?
12/23/2010 9:58:00 AM EDT
[#2]
Notched bolt?
You can manually retract the bolt to the max and it doesn't lock.
Crackedcornish has the right question.
It can't recoil more tha about 1 7/8" before the bolt hits the back piece.
I can imagine several types of hammer besides a normal DPMS type that I can imagine locking behind a cocked hammer.
Some sort of buffer between the bolt and rear place limiting rearward travel could solve this problem, which is common to Atchisson MKI bolts from MAK (the tubular conversion). When the buffer on this one cheeses out, it's subject to what you describe.
12/23/2010 10:37:09 AM EDT
[#3]
After looking at a M-261 and a lower, the ONLY thing I can see that can catch a bolt is the bolt catch.

If it's a little high, it could catch the bolt.

In fact, if the bolt catch spring isn't too strong, and you have a good follower, the bolt will be locked open with a GI mag (and no insert) so single loading is possible. Useful for Service Rifle competitors.

Make sure there's not a burr on the rib on the bottom of the bolt, and that the bolt doesn't drag on the catch. Sometimes, a few strokes of a file on the top of the bolt catch fixes stuff like this.
12/24/2010 10:36:02 AM EDT
[#4]
Looks like it just locks on the bar, hard to take a picture, releases when I pull it out. I can not find detail drawing ' Is there a stop or is it just the spring that stops it?
Using it on a RRA 2 stage trigger.
12/24/2010 11:10:24 AM EDT
[#5]
It sure sounds like it's catching on the Bolt Hold Open. If that's the case
a little file work on the top of the catch should fix it...


Is your hammer rounded or notched? That's the only other thing I can think of...
12/24/2010 6:19:07 PM EDT
[#6]
"Locks on the bar".
What bar?
Work with us here.
12/24/2010 6:36:39 PM EDT
[#7]
I think.....but not sure....that your bolt is over riding your hammer and locking back. If you have the notched hammer, cut that notch off or replace the hammer. The cocking pad on these style of conversions are just a little too short. You can also try putting some sort of spacer on the rod to keep the bolt from coming back too far as well.....but no more than about .06"

Tim
12/24/2010 6:52:27 PM EDT
[#8]
Merry Christmas Tim.
12/25/2010 6:22:01 AM EDT
[#9]
Are you using Black Dog's M-261 magazine or the GI issue mag insert for the 30 round GI mag?

In all my years of small arms experience in the USAF, I can recall seeing the Army's M-261
(or our own adapter for that matter) having bolt issues mostly resulting from the rifle being really dirty.  
Especially the bolt catch well being filled with fouling and excessive carbon on the top of the bolt catch.  
If you keep your rifle clean, this wouldn't be an issue, so I'd check the catch for free movement, burrs,
or distortion (although not very common).

There was one situation where a bad extractor was binding on the bolt raceway, and a few where the guide
rod was heavily burred or bent and stopped the bolt, but these were so easy to spot even a trainee could see
the problem immediately.  There were also instances where the GI insert wasn't fully
captured under the mag lips and shifted forward and titlted up just enough to keep the bolt from closing.
But these were very unusual cases resulting from gross negligence.

Other than these experiences, I'm at a loss to explain your problem.  Anyway,
Merry Christmas To All!

Ted
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