My rifle will double every so often with higher velocity ammo.  I can shoot Wolf all day and not have this problem once, but if I switch to XM193 I'll get a double every hundred rounds or so.

My FC group has less than 1K rounds on it and the hammer/disco checks in the sticky appear to be good.

I have done the "15 minute trigger job" to my hammer spring (cutting the one leg, but not bending the other).

My hammer spur is bouncing off of the disco a little (I see a wear spot on the top of the disco).

I suspect I had a worn buffer spring as my empties were being ejected towards the 1 o'clock position (just installed a collapsable stock w/new spring and buffer but haven't shot the gun since the install).

UPDATE:  Dremilled about 1/8" off the hammer spur.  Shot 100 rounds of my hotter reloads without a problem today.  The new recoil spring/buffer has the empties landing in a two foot square area at 2 o'clock.

Thanks folks, I appreciate the help.  

Who made the lower receiver?

Quoted: Who made the lower receiver?

Oly (forged).

If you have done the lower function test and ruled out the trigger group you may want to check the distance of the trigger pin hole from the top of the lower down to the hole and make sure it is not to further down than the maximum the print allows.

Shorten the tail of the hammer to correct the disco bounce (.040 is a good starting point), and check the free gap between the disco and hammer sears (should be around .003 with the trigger at rest).

The lightening of the hammer spring does not effect the amount of tension that the disco applys to the hammer, so either the disco bounce is allowing the hammer to escape, or the sear engaugement is on the short side, and needs to be increased to retain the hammer during the harder xm-193 cycle (read harder jaring of the carrier on closing).

Quoted: Shorten the tail of the hammer to correct the disco bounce (.040 is a good starting point), and check the free gap between the disco and hammer sears (should be around .003 with the trigger at rest).

Shortening the hammer spur was the direction I was going, just wanted to confirm.  I think the new recoil spring will lessen the "slamming" a little too.

Thanks.

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