Gunsmithing Help with LMT Sharpshooter double tap

[Gun_Doc]

Gents, I'm working as an SSgt Armourer with the British Army and we're running a sharpshooter cadre with our L129A1 Sharpshooters (LMT 308 MWS).

I've just had 2 brought into my workshop that have been firing intermittent 2 rounds bursts/ double tap. I've trained and worked on these for a year now but can't for the life of me work out how this is happening.

Both are relatively new weapons and have crisp hammers and sears. Any suggestions?

 

[Redmanss]

If you can't induce it dry firing or on the range, it's likely the individual shooters are causing it. Firing a 7.62 semi auto is known to cause this issue when the shooters are trying to be too gentle on the trigger, and on the recoil pulse it causes a "bump fire". There is actually a recent thread on the same situation: http://www.snipershide.com/shooting/snipers-hide-semi-auto-rifles/212073-double-taps-my-lmt.html

 

[glbreil]

That can also happen if the spring tension on the disconnector is to light or the disconnector is out of adjustment , however I doubt it is adjustable on a standard trigger so if its not user error I would replace the disconnector spring.

If the disconnector happens to be adjustable then go for a little more engagement. This happens when the disconnector releases the hammer before the primary sear is engaged.

Happens all the time on standard AR's.

Thanks Gary

 

[Graham]

Tell the shooters to triple the pressure with which they are holding the rifle. Chances are they are slapping the trigger while holding the rifle too lightly.

 

[Gun_Doc]

Gents, many thanks. I'll get out with them on the range this afternoon.