11/4/2011 NEWLY UPDATED ON GUY FAWKES EVE BECAUSE EHOW REMOVED MY ARTICLE
To extend my FS2000's overall length beyond the California-required 30", I decided to remove my FS2000's factory flash hider. (If you are in California, be sure to keep your gun disassembled while you are removing the flash hider so that you do not break the law. Another post on another thread in this forum confirms that the ATF says it's okay to remove the flash hider once the gun has been imported into the US since the barrel is over 16" on its own, without the flash hider attached. Be sure to obey all local laws while making these modifications.)
Step 1: Find the pin.
Familiarize yourself mentally with the pin's orientation. Looking at the wrench flat from the side, the pin goes directly away from you.
This is a view from under the barrel to see how the pin cuts right across under the bore. The first pin slot, on the left, is not used. It is the second pin slot, on the right, in the middle of the muzzle threads, that is where the pin is located.
Step 2: Get a drill press or ever a handheld power drill and a drill bit that is the same diameter as the pin. Do not get a bit that is too small--you must destroy the pin completely in order to be able to remove the flash hider. And absolutely do not get a pin that is too large, as you will damage the muzzle threads if you do so.
The pin is soft--much softer than the surrounding steel, so you can do this easily with any drill bit meant for metal.
Step 3: If you have a drill press, it helps to clamp the barrel using wooden or nylon blocks on the wrench flats to keep the bit aligned axially with the pin. If you are doing this with a hand drill, try to use an armorer's block such as this: http://www.brownells.com/.aspx/pid=2...ON-BENCH-BLOCK to secure it somewhat. Most any AR15-style barrel clamp can also help you secure the barrel in a vise, if you like.
Step 4: Working carefully, with slow pressure, drill through the pin, destroying it in the process. BE VERY AWARE OF THE FEEL OF THE SOFT METAL OF THE PIN AS YOU DRILL. The pin is very, very soft, so drilling it is very easy. But behind it is harder steel (the other side of the flash hider), so you will immediately run into noticeable resistance when you have destroyed the pin and hit the inside of the flash hider. Also, you do not want to drill any of the barrel itself, and since that is very hard steel, you should also be able to tell by feel if your drill bit is not centered properly.
Step 5: With the pin completely drilled out, the flash hider will simply screw off. TURN RIGHT/CLOCKWISE TO LOOSEN, since this is a left-hand thread. GO SLOWLY AND BE GENTLE. You should resist the urge to twist the flash hider until you are fairly certain you destroyed all of the pin. If there are any bits of the pin left in there, they can make it difficult to remove the flash hider. If you use too much force and there are bits of the pin still in there, there is a small chance that the bits will chew up the muzzle threads.
Never fear, however. If on the off chance that you did damage the threads, it's nothing a 9/16"-24 lefthand tool die can't clean up. You can get a cheap one here for around $15: http://www.wttool.com/index/page/pro...djustable+Dies
Make sure when you order that it is a LEFTHAND thread.
Midway USA sells the same die for around $60.
Alternate approach: You might notice from this photo that I Dremeled away some of the flash hider surrounding the pin. This was so that I could simply pull the pin straight out using a pair of pliers.
Now, to help others who have questions about dimensions, I have these additional photos of my FS2000 with digital calipers, just for fnforum.net. All measurements are in millimeters.
Length of the flash hider, 82.75mm:
Length of barrel hidden under flash hider, from crown to butt of flash hider, 45.21mm:
Length of flash hider, from crown to tip of flash hider, 37.45mm:
Length of exposed barrel, between gas block and butt of flash hider, 61.85mm:
Length of exposed barrel, between gas block and crown, 105.41mm:
Length of threading, 10.41mm:
Barrel diameter, without flash hider, 14.67mm:
Flash hider diameter, at butt, 21.90mm:
So, why did I not measure the locations of the pin grooves? Well, they don't matter for planning purposes. What really matters is the location of the crown, hidden under the flash hider.
Hope this info helps somebody else. I was greatly helped by the posts here on how easy it is to drill out the blind pin, and this is my way of giving back.[img][/img]