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5/7/2007 4:46:51 PM EDT
Is there any?

Just bought a kit but I'm getting light primer strikes.  Most of the time the round does not discharge.

anyone have any tuning tips or know where I can find some info on possible adjustments?

Thanks
5/7/2007 6:08:29 PM EDT
[#1]

Quoted:
Is there any?

Just bought a kit but I'm getting light primer strikes.  Most of the time the round does not discharge.

anyone have any tuning tips or know where I can find some info on possible adjustments?

Thanks
I don't think there are any adjustments.  But assuming you've cleaned the ever lovin' snot out of it, particularly the firing pin and its raceway, I'd want to know where yours came from.  My 261 is GI, (and probably well used) but a brand new one may take some polishing or breaking in.
5/7/2007 6:53:35 PM EDT
[#2]
I have an Oly m261 kit.  When new, it took some minor polishing before it felt smooth when I cycled it.  I did not try and fire it before I smoothed off the rough spots.  Can you tell if the firing pin is binding in the channel?  I can think of 2 things that could be causing a problem-
1.  Pull the firing pin section of the m261 off the spring/slide section.  Press the firing pin "button" on the back and feel if it is smoothly operating.  Then check and make sure the firing pin protrudes from the bolt face when you press.  When the button on the back is depressed the end of the firing pin at the bolt face should protrude so that it is just shy of being flush with the taller section of the bolt face.  The end of the firing pin should look like a small straight screwdriver tip.   If the firing pin is binding it will slow the pin causing a light primer strike.  You can easily dissasemble these parts and lube/polish.
2.  Check and make sure that the firing pin section slides smoothly on the rail.  Roughness would more likely cause a failure to chamber/eject but you might as well check it anyway.  Polish as necessary.

After my minor polishing session and some CLP mine runs like a champ in all my AR's.  I hope my descriptions of the parts are intelligible.

5/7/2007 7:00:17 PM EDT
[#3]

Quoted:
The end of the firing pin should look like a small straight screwdriver tip.


At least many M261 kits came with a blunt, cylindrical firing pin.  A common mod is to grind/file the tip into a chisel point.  Use a factory .22's firing pin as a model.
5/9/2007 11:30:52 AM EDT
[#4]
My M261 would fail to fire due to the "bolt" not closing completely.  A combination of deburring, polishing and adjusting the spring that is opposite the extractor seems to have eliminated this problem while cycling manually.  I'll be test firing this weekend.

The wire spring opposite the extractor seemed to be the biggest cause of the bolt stopping just short of closed.  It was loose.  It can be removed by inserting a thin tool at the groove in the top of the bolt and gently prying/lifting the spring up.  Carefully bending it will adjust the tension that holds the case on extraction, and in my case tightening the spring resulted in much less friction when the spring moves as the bolt closes.  
5/9/2007 11:39:26 AM EDT
[#5]
Wolf XP Hammer Spring & carefull ammo selection.  Mine likes the Federal valuepack from Walmart.
5/9/2007 4:31:51 PM EDT
[#6]

Quoted:
Wolf XP Hammer Spring & carefull ammo selection.  Mine likes the Federal valuepack from Walmart.


Is that the AM22 or the 750?
5/10/2007 3:55:57 AM EDT
[#7]
I believe Fed Valuepack is 750. Good reliable ammo but not particularly accurate.

Make sure your chamber is CLEAN CLEAN CLEAN. Dirty chamber is often the cause of misfires/duds with these things. Keep shooting with a dirty chamber and sooner or later you'll get a KABOOM, which will be the most exciting (and probably most expensive) thing that happens to you all day.

The M261s also like to be well lubed. Especially lube the recoil spring and its guide rod.
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