Front Sight Base F - FSB (ID .750) - Milspec for Flat Top Uppers

Stock Status:
The "F" marked forged front sight base is a hard product to find. Mil-Spec for rifles issued to the troops require taller front sight bases on all flat top AR rifles. (.750")
Designed to match the height of Mil-Spec height rear iron sights.
These are new and are not yet drilled for taper pins, and should be installed by a qualified gunsmith.
This includes front sight base only. (Not included are front sight post assembly, sling swivel assembly, and taper pins.)
***This product contains chemicals/materials known to the State of California to cause cancer and other reproductive harm. To learn more, visit***

48 Reviews

  • 5
    Front Sight Post

    Fit and finish were good, installed on a flat top carbine model upper, .750 barrel, tapped bottom hole in post with an 8/32 tap, installed a 1/4" long 8/32 allen head screw to hold the front sight mount in place when drilling on the drill press. Drilled pin holes #30 drill bit, reamed with a 2/0 reamer, perfect fit. Removed the 8/32 allen screw, installed the sling loop and swaged the rivet. Good to go. BTW, you will need to order the actual front site post, spring and plunger to finish populating this front sight. I ordered a square front site post to eliminate the burring that occurs with round style front sights. Bottom line: I would order it again, no hesitation. If you don't have a drill press and drill press vice, I would suggest ordering something else already finished. Total amount of time to setup and drill was about 45 mins, your mileage will vary.

  • 4
    Worth the purchase! You need it? Buy it.

    The sight fits well, as needed, and has a little weight to it, so it seems sturdy. I also like that there is a roughness to the ramp and verticals. This should prevent glare and provide “toothing” for the paint if I decide to camo this rifle.

    I am very pleased.

  • 5
    M16A4 Clone Project

    Picked this A2 FSB up for a M16A4 clone that I'm putting together. Just got it finished a few days ago and everything turned out great. My build was a National Match style build so I had to cut off the sling swivel mount and blue it since the national match free float tube has a sling mount included. The front sight post again was a national match style thinner blade. Everything came together nicely and BCM always delivers.

  • 3
    First purchase ever

    Product over priced for what it is. Doesn't come with pins or even the front sight post for installation. I'll go somewhere else where pins and sights are included. Don't waste your money on this price and shipping.

  • 5
    Excellent piece

    Perfect fit for my build

  • 5

    Bought a few of these for builds. Worked out well.

  • 4
    A2 front sight base

    The FSB is top notch, just be aware of some things though. First it does not come with the taper pins or the front sight pin assembly, these will need to be ordered separately. Additionally as you can see in the picture, the pin holes are not drilled, some gunsmiths don't want to mess with a FSB without the holes drilled so check with your smith first if you're not doing the work yourself.

  • 4
    Great Quality FSP

    Nice, heavy duty front sight post, came slightly oiled for rust protection (i assume). Wish it came with front sight installed considering its only a few more dollars that i’d gladly pay to not have to order it separately

  • 5

    Fit and finish is good. Hard to find these online atm. Nothing special about it.