BUIS question again!

[Uncle Alvah]

I'm having trouble telling which rear BUIS's are most compatable with the standard/low sight tower-gas block arrangement.
Many of them seem to be made for use specifically with a flip-up front.
I'm wondering what models might be most suitable for use with a tower, either low or high, or if I might be as well/better off to go to a detach carry handle for occasional iron sight use?

[Luke_Y]

If I am understanding your question right, I'll try to help.

Most AR platform rear BUIS, either fixed or flip-up are of a standard height, to match up with the height of a standard F marked FSB. The front BUIS will vary in height by mounting method, to match the height of a standard FSB/rear sight. A rail mounted front sight will have a lower overall height than one intended to be mounted on a low profile railed gas block (because the rail is higher). If a gas block with rail is designed to be the same height as the standard rail, you can use standard height front sights.

There are some rear sights for unique applications that are of a non-standard height. But, the info is usually noted in the descriptions.

[Uncle Alvah]

Thanks for the reply.
I cannot find an F on my front sight, but I understand thats common. At any rate, I bought an inexpensive(yeah, I know, I know...) BUIS and fired it a bit saturday evening. Shoots a tad low, but I'll probably just take up the elevation with the front post.