Standard front sight base with scope?

[d.hodgee]

I am thinking about pulling the pin and buying a BCM midlength upper. I want to run a scope of some sort. Nothing major but, say a lower power Leupold using a Larue Mount.

My question is with the standard F-Marked Forged Front Sight Bases....
(any manufacture not just BCM)

-Will it be awkward looking through the scope with the Front Sight Base sticking up in view? I have no experience with this I have pretty much always had irons only on my builds.

-Would I be better off opting to a low-pro gas block with some flip up sights?


I'm pretty much open to all ideas. Thanks for your time.

If you have any pictures of this exact set up feel free to throw them in~! Sticks gun pictures always seem to motivate!

[ColonelColt]

This is related to something I was going to post about but if I can get answered here, great. With railed gas blocks - Are they all a standard height or do I need to worry about finding one that matches my folding or fixed clamp on front sight? What about folding front sights built into the gas block? Right now I have a YHM built in folding front sight I like but I've often wondered about using it with different rear sights. A slight variance in height between different manufacturers could throw your elevation pretty far off requiring a lot of adjustment.

[m24shooter]

You didn't say what power scope you were going to use. Here's how a FSB looks through a 3x EOThingy magnifier. Higher mag powers will have even less of an effect.

[m24shooter]

This is related to something I was going to post about but if I can get answered here, great. With railed gas blocks - Are they all a standard height or do I need to worry about finding one that matches my folding or fixed clamp on front sight?

Front BUIS that are rail mounted are usually in two heights: rail mounted or gas block mounted. Meaning the gas block mounted sights are taller because the gas block rail is lower.

What about folding front sights built into the gas block? Right now I have a YHM built in folding front sight I like but I've often wondered about using it with different rear sights. A slight variance in height between different manufacturers could throw your elevation pretty far off requiring a lot of adjustment.

The folding front sights should all be the same height deployed as a standard fixed front sight.
ETA: Be advised there are gas blocks with rails that are the same height as tube rails.

[ColonelColt]

Is there an easy way to tell which gas block is which? I would hope they would tell you but you never know. It sounds like I you just have to get the right front sight/rail combination. The DPMS mangonel sights I have winging their way toward me right now have a position for both heights but what about Magpul front BUIS? I think I've only ever seen them mounted on a full rail system, but then, I've also seen people mentioning how high the sight post rides in those. While I don't plan on putting a rail system on my rifle in the near future, it might make more sense for me to get the rail-height gas block if it will give me more front sight options or if the ones I do buy will end up being more versatile later on. Thanks again.

[d.hodgee]

You didn't say what power scope you were going to use. Here's how a FSB looks through a 3x EOThingy magnifier. Higher mag powers will have even less of an effect.

I have been wanting another leupold. Probably something like this or lower power. Leupold 2.5-8x36mm MR/T M1.

[m24shooter]

Usually the gas blocks with taller rails will indicate that they are rail height.
The Magpul sight is intended for rail height mounting. Most people mount them on a rail tube, I don't know that they would do well on a gas block acting as a heat sink.

[m24shooter]

At the lower power setting you will see some ghosting of the FSB. The pic I posted is of the 3x magnifier, so that will give you an idea.

[d.hodgee]

At the lower power setting you will see some ghosting of the FSB. The pic I posted is of the 3x magnifier, so that will give you an idea.

Thank you for the picture. I haven't decided which way to go. 12" rail with lowpro gas block or 9" rail keeping the fsp.

[Russ4777]

Generally, you will not notice the FSB in the scope image. especially with a scope greater than 4X.