I for one do not care for the A2 grip.  It's doable, but not something desired.  Better grips are out there.  I like the Magpul MIAD and MOE.  

The FN Scar lower was molded incorrectly with an oversized grip tang.  You could not simply remove the A2 grip and replace it with an after market one unless the grip tang cavity on the grip was oversized.  

I called Bob (FN) and Jeff (Tangodown) and they said the same thing.  Modify the grip or the tang.  With the release of the black Scar, I had hoped that FN "corrected this", but no joy.

Two options....mod the grip or mod the tang?  Modding the grip will weaken the grip (less cross sectional material left over when done) and you can't use another grip down the road.  Mod the grip tang and you can attach almost any grip provided it didn't have a backstrap.  So you could use a Hogue.  Downside.....if you FUBAR the tang.....your fXXked.

So, here we go......(it is your resposibility if you FUBAR this up.  I take no liabilty for YOUR mod.)

BE SURE ALL WEAPONS ARE UNLOADED!!

I presume that anyone that has a Scar, already has a M4 and clones.  If so, this will go much quicker.

Here's my Colt 6920 (that I know is in spec).  Remove pistol grip.


Take a piece of paper so that you can use the corner to overlay against the grip tang.  Crease along the three edges of the grip tang.  Cut along the creases and corner.  This will give you a rough template of the in spec grip tang.  Trim the template to fit better on the M4 grip tang.


Here's the template.


Tools that make the job easier: safety glasses, dremel, medium grinding wheel, fine polishing wheel, flat file, pencil or marker.


Again, be sure your weapons are unloaded!!

Remove grip from Scar.  Use your new template and overlay it on the Scar grip tang.  As you see, there is too much material on the diagonal edge.  Approx. 1/8".  (I already started grinding, so there's not much left on the template)  Once that is removed, the other edges come into close to spec with the template.  Use a pencil to mark the excess limit to remove.


WEAR SAFETY GLASSES!!  
You'll get hot shards of plastic in your face depending on the rotation of the Dremel wheel.

GO SLOW if you use a Dremel and leave plenty of room to hand file for the final fit of the edges.  Use the flat file to make sure the grip tang is flushed!


Check for grip fit every so often.


Personally, I like to choke up on the grip and the B1 backstrap is no better than the A2 grip to begin with.  I wished someone else had posted a "How to do for dummies", since I wasted a MOE during the "learning process."
This is the B3 backstrap I used as the "second" try.  You can see the interior profile needed from the rear view.  


Here's the B2 backstrap on the left with the needed profile and the MOE on the right with a much shallower profile.


Here's the top view of the needed contours of a B2 backstrap.


BE CAREFUL GRINDING AWAY NEAR THE EDGES.  I got too close on the MOE and B3 backstrap and caused a flat edge on the upper right curve as seen below.  (MOE on right, B3 in the middle, B2 on the left).


Go slow and try fitment.
Finished end results.





The MOE was my first attempt.  The B3 was the second and I got the profile needed down pat.  The B2 was the final attempt.  I did it in a minute.  Remember to stay away from the edges or grind there too long.  You don't want a flat when it should be a curve.

I used the factory Scar grip screw.  And checked for clearence against the lower trigger flat.  Cleared fine.  IF YOU REMOVED MUCH OF THE DIAGONAL FLAT, THE FACTORY GRIP SCREW COULD CONTACT THE TRIGGER FLAT.  USE A CUTTING DISK.

And no, I did not do this in my living room.  A good vacuum can hide evidence.  

Hope this helps someone out!

Awesome write up, thanks for the tips!

I REALLY could have used  this post yesterday!
Good job, thanks!

How did your mod go?

I was nevous sanding/filing on my rifle,but I think it's better to mod the gun,rather than weaken the grip.

Yep, know what you mean.  Going slow was key.  You can't make stuff grow back.

Thanks for posting this.  It's exactly what I needed to see before I put a MOE grip on my SCAR.

Excellent tutorial!

looks great

Thanks!

a little bump to this post, I just did the same to my SCAR.  Easier than it looks, just take your time.

scout,
Looking good.  

I had the same optic setup.  Is your dot oblong when viewed thru the 3X?  Crisp or vague?

no, it's crisp for me.  That might be the PRK talking, but I have no problems with it.

Excellent information!

I just did this mod. Modifying the B3 took the most time as I did not want to remove too much material. I kind of wish Magpul would make a SCAR-specific MIAD but I can understand the cost associated with the mold.



I prefer the B3 because it gives me a more comfortable grip and more leverage. I can now "John Wayne" the SCAR 16S with the stock folded more easily. The A2 grip was a torture device.

Outstanding!  Glad my post helped you out.  Good to know there are others with balls who are not afraid to mod their tools to fit their needs.  

Tired of the "I don't want to mod my $2k rifle" replies.  

I was really apprehensive about modding the lower receiver on that SCAR, but it didn't seem like it would affect the integrity of the receiver.

As a side note, if you happen to remove too much off the grip tang flat, you can shim it back by using flat washers cut to shape placed between the grip tang and grip.  The lowers are $80 if I recall (worst case).

As a side note, it seems that the black SCARs (at least S/N 17XXX) does NOT have the revised grip tang as some have claimed.  Someone claimed on fnforum.net, that the tang was "revised".  Evidently not.

TACT1975 had to do the tang mod on his newer black Scar.

A thankful bump