FN SCAR 16S Fire control group pix (updated 08-05-09)

[SgtStrykerUSMC43]

I got around to taking it apart to determine the difficulty in improving the overall quality of the trigger pull without risking safety or reliability. The following pix are just the parts removed from the weapon without any modifications.

Step 1)
This image shows the selector switch assembly. To remove the unit, you simply remove the slotted screw from the right side selector lever and then pry up the head with even pressure around the base until it comes off. The lever is removed from the left side of the lower housing. Similar to the FAL series.


(Image for reference)
This image shows a small spring clip and its location, that should be removed in order to allow the right side locking plate lateral movement in order to allow the hammer strut guide to be removed.


Step 2)
This image shows the left side locking plate, hammer, hammer strut with spring, hammer strut guide, hammer axis pin, and the spring clip removed. The left side locking plate is moved to the rear after the selector switch has been removed. This allows the hammer axis pin to be removed from the left side of the lower housing.



This image shows a close-up of the hammer, hammer strut and spring, spring clip, and hammer strut guide.



Step 3) Remove the trigger axis pin from the left side of the lower housing, then the trigger, trigger spring, disconnector, and disconnector spring follow by being lifted up and out of the lower housing. Reassemble in reverse order.


UPDATE: 08-05-09


The set-up doesn't readily lend itself to an improvement. Its design relied heavily on the FAL, but in the FAL, the sear is spring loaded and moves along the fore and aft plane in the weapon, whereas in the SCAR the leading surface on the trigger engages the hammer's notch, eliminating the sear. The issue is the hammer has a positive angle, and during the trigger's movement to the rear, the hammer is actually drawn down, resulting in a heavy, poo-poo trigger pull.

That's what I get from it so far.

The best I can come up with right now for improving the SCAR trigger is this:

ATTENTION: BE 100% CERTAIN THE WEAPON IS UNLOADED!

A Trigger Stop Screw for the SCAR 16S Rifle:

1)Remove the pistol grip retaining screw.

2) Go to hardware store and find one with same thread pitch, with the difference being the one you get is 1/4" longer.

3) With the lower housing removed from the weapon, rotate the safety to "1". The hammer should be cocked.

4) Install the new screw into the lower housing until it comes in contact with the bottom of the trigger.

5) Keep turning the screw slowly until the hammer is released. You want to cushion its forward travel so it doesn't stress anything when released.

6) Back the screw out slowly, and at the same time depress the hammer until the hammer and trigger reset.

7) Make note of the difference in length between the original grip retaining screw and the new one, comparing how much difference there is between the two in order to fasten the grip securely.

8 ) Remove material from the thread-form end of the replacement screw until you are close to your measurement.

9) For a final fit, I suggest leaving the screw a long and doing a trial grind and check for fit with the grip installed.


*WARNING*
This will not improve the weight of the trigger pull at all. What it will do is decrease the reset distance in the trigger and length of travel that the trigger has to go through in order to release the hammer. The result could potentially be a very short trigger pull dependent upon how long the screw is left. As always, common sense...

Of course a surface grinder would work best for modifying the pistol grip retaining screw, and I suggest a stainless steel screw for a replacement. They are softer than their counterparts and less susceptible to corrosion.

I'll keep you Gents informed if I may have overlooked something and edit the post accordingly. Like doing both a muzzle first and buttstock drop test after the new screw is installed, and a complete range session.

Disclaimer: You men being adults and owning firearms know that if you decide to do any modification to any weapon, you do so at your own risk. If you don't have enough common sense to approach and proceed with common sense and caution, do not attempt to do this. Hire a professional gunsmith and have him do it.




PEACE THROUGH STRENGTH

[spartanranger]

Excellent post! I am looking forward to hearing what you think we can do to improve the trigger.

[djv38]

Excellent post! I am looking forward to hearing what you think we can do to improve the trigger.

ditto

[SgtStrykerUSMC43]

Thanks Gents.

I'll stay with this until it's done. But, from what I could gather so far in looking at the parts, a 2-stage ala AR-15 can easily be done for the SCAR. It's just a matter of willingness, money, material and time. The market is already there.

For me, it's just a wanting to clean up the factory trigger.

PEACE THROUGH STRENGTH

[SONYtec]

Nice work Sgt.

Would you be able to take a picture with all the internals positioned as if it were in the receiver?

Would like to see how all those pieces fit.

[JDL USMC]

Great pics and info Devil Dog!
Very useful info

[michaelrabern]

Could you use washers?

V/r.,

M

[SgtStrykerUSMC43]

Could you use washers?

V/r.,

M

The use of washers for what?

PEACE THROUGH STRENGTH

[bigbadbull]

So there is no way that a FNC trigger group will fit?
One of my friends insists that it will.

[SgtStrykerUSMC43]

So there is no way that a FNC trigger group will fit?
One of my friends insists that it will.

I dunno. Have your buddy take and FNC FGC and try it in his SCAR.

PEACE THROUGH STRENGTH