Question about FSBs and rear sights

[Lazarus]

Does anyone know which FSB I need to work with a MaTech BUIS rear? F marked or non-marked FSB?

 

[CQB27]

"F" marked

 

[DanKATL]

Does anyone know which FSB I need to work with a MaTech BUIS rear? F marked or non-marked FSB?

F marked or equivalent (many are no longer marked).

 

[CQB27]

A non "F" will work too, but you are going to have to have an extra tall front sight post.

 

[Lazarus]

F marked or equivalent (many are no longer marked).

Really? I'm swapping out a barrel and the new one comes with a non marked FSB. Do you think theres a chance its the same?

 

[Lazarus]

A non "F" will work too, but you are going to have to have an extra tall front sight post.

But it will all witness the same?

I'll end up having both, I might just keep the F marked

 

[CQB27]

But it will all witness the same?

I'll end up having both, I might just keep the F marked

I'm not sure what you mean by "witness the same"?

A "F" marked front sight base is 0.04 inches taller than a standard front sight base

A taller front sight post (Bushmaster used to make them, don't know it they still do) is exactly 0.04 inches taller to compensate for the shorter standard FSB. You should have no issues zeroing or co-witnessing an optic with a "F" or standard with taller front sight post FSB with a MaTech rear.

 

[DanKATL]

Really? I'm swapping out a barrel and the new one comes with a non marked FSB. Do you think theres a chance its the same?

But it will all witness the same?

I'll end up having both, I might just keep the F marked

Measure it to confirm. The difference is very small.

 

[DanKATL]

I'm not sure what you mean by "witness the same"?

A "F" marked front sight base is 0.04 inches taller than a standard front sight base

A taller front sight post (Bushmaster used to make them, don't know it they still do) is exactly 0.04 inches taller to compensate for the shorter standard FSB. You should have no issues zeroing or co-witnessing an optic with a "F" or standard with taller front sight post FSB with a MaTech rear.

KNS did sell an assortment pack of varying height and diameter posts, not sure if they still do.

 

[Lazarus]

I'm not sure what you mean by "witness the same"?

A "F" marked front sight base is 0.04 inches taller than a standard front sight base

A taller front sight post (Bushmaster used to make them, don't know it they still do) is exactly 0.04 inches taller to compensate for the shorter standard FSB. You should have no issues zeroing or co-witnessing an optic with a "F" or standard with taller front sight post FSB with a MaTech rear.

I mean like co-witnessing or lower 1/3 with the MaTech and either the EoTech or ACOG I'll put on.

Thats I did see this picture when I searched the sight. I'll just keep the F especially if it seems it to be a little rarer.