First off, thanks for looking in this thread and any helpful comments that you may have..................

I am in the process of building up a SBR 9mm and have a question in regards to the FSB. I have removed the standard front sight and am looking foreward to cutting the barrel down to just longer than the front handgards. I will probably be putting an EOTech or JP for the main sight, but would still like to put backups on it. I suppose that I should mention that it is a flat top upper with a YHM free floating front hand guard on it. What I need to know is, can I buy a back up front sight that fits on a FSB and have it be the correct height to work with the rear sight. Or do I have to get a special height front sight? Is a front gas block the same height as the YHM front hand guard?


Thanks,
Nox

Yes, I have removed the front sight from the barrel. Since there is no gas block to bolt anything to, I need to bolt it to the forward hand guard. My question is will a standard one made for a gas block work with the front hand guard or do i need a special height one?


Nox

None. It's a 9mm upper. Straight blowback. Not gas operated.

What hole?

There should be no hole on a 9mm barrel.   If you cut the barrel just short of the rail, then you'll need a rail mounted sight unless you left just enough room for an FSB...

TS