The only BUIS sight I have is DPMS mangonel rear (I also own the front as well) I am wanting to purchase a new one that doesnt take up so much room. The DPMS BUIS is the fastest I have ever seen,  it will deploy as fast as I flip it up, no pin switch or button that has to be pressed. It is spring operated and works great but I am on the bandwagon for a more accurate meaning I need one that has the smaller peep sight, as this one has only the larger peep sight. some suggestions are exactly what I am looking for, also some pics will be my ultimate buying point. Ultimately, what is the fastest deploying BUIS?

Many of us use the Troy rear flip-up. It's got a very low profile when collapsed also which is a great benefit if you want to run an ACOG



And my personal choice for a fixed BUIS (you won't get any faster deployment then this )

Well, if pure speed is what you want, then don't buy a flip up at all, get a fixed sight.

That said, if you need the thing out of the way, another vote for the Troy.   You have
to push a button to fold it, but to raise it you simply flip it up.  

And it's tiny.

i use the knights 600meter buis.. best buis i have ever used

Quoted: Well, if pure speed is what you want, then don't buy a flip up at all, get a fixed sight. ...

And we have a winner!  LMT or LaRue fixed BUIS.  There is nothing faster than closing one eye to use irons.  I have the LMT and it's bulletproof, pretty light too, even with the elevation and windage adjustments.  MJD