TargetTalk

I own a LP10 (mechanical trigger). My problem is that the trigger cannot be adjusted
in the longitudinal direction due to the countersink screw being really tightened at the
factory. So how can i loosen it ?
Do i need to apply some lubricant ?

Put a drop of oil on the screw and let it penetrate the tread (wd40 or some thin oil).
Find a screw driver that fits the screw head with no slack.
You probably need to use a little more force.

Best of luck

Oil might not penetrate. Try using something that gets in on a molecular level, like Kroil. Also, try to put something behind the srew so that the pressure you apply does not bend the rod the screw is attached to. Also, the idea about an exact fit of the screwdriver is spot on. You can try to slowly turn the screw, but more often than not, you will need to apply a quick, sharp snappy, motion to dislodge the screw. Just make sure the screwdriver is well seated.

Good Luck,

Joel

I second the recommendation to use Kroil. Let it sit for a while so it can penetrate.

My Steyr and all I saw have hex screws, so maybe it was replaced some time and locktite applied? This if none of the above helps then some gentle heating might help.

Mine also came with a slotted screw.

From the parts list and exploded draw:

58.4 Slotted raised countersunk head screw DIN 964 M3x8

Any luck so far getting that screw lose?

I just picked up two used LP10's for the MIT collegiate team. One LP10 that came with cylinders dated 2004 has the slotted screw, and one with cylinders dated 2008 uses a hex key set screw. The hex screw was pretty tight, I haven't had a chance to adjust the trigger on the one with the slotted screw yet. It's offset & at an angle, so it's going to need tweaking.

I haven't ha a chance to go over them thoroughly, but there appears to be a number of small changes made over the years. I hadn't realized they had been around since 2004.

Mine is from November 2011 and has a slotted screw.
They were introduced in 2000 (according to Wikipedia)

Thank u RMCA, joel & others for the assistance. I took my LP10 to a local armory and they only took a sec to loosen it. The armory is "Thekkan armory" locatted in Cochin south India. Any way thanks a lot for the help friends :))