What's the smallest AR rifle BUS on the market?

[Caseless]

I plan to mount two small sights onto both 45-degree rails on a Warren RAMP mount. Need to keep the rifle width as narrow as possible. So folding sights only. Magpul Pro? Troy?

http://warnescopemounts.com/product/r-a-m-p-mount/

[TheExiled]

The MBUS pro are very small, I'm not sure of any smaller but the KAC micro rear might be close

[Niviticus]

I just got the Magpul MBUS Pros and they are the smallest I've seen and used so far. I wrote a little comparison on them with my old MBUS gen 2s.

http://www.calguns.net/calgunforum/showthread.php?t=890916

[EvolutionGSR]

Both rails as in two sets of sights, one on the left and one on the right?

[Caseless]

Both rails as in two sets of sights, one on the left and one on the right?

Yep. The original plan was two tritium RMRs, but they make the rifle too wide to fit in a quad-rifle case.

[strongpoint]

do you know for a fact that angled rails plus folded sights will actually make the rifle more narrow than dedicated angled sights?

[AreWeFree]

Are you adding both front/rear sights to the mount itself? Do you already have that mount with 45 offset?

XS Sights has slim looking angled sights that are more like pistol sights. Didn't look up dimensions but they will probably be much narrower than a set of flip ups.

[ky2970]

Troy Micros

https://troyind.com/products/micro-set-m4-front-and-dioptic-rear-fde

Also, I know you said folding but HK fixed irons have a low profile too.

[Niviticus]

Check this out. It compares the Magpul MBUS Pros to the KAC Micros.

http://www.ar15.com/forums/t_3_18/633833_KAC_micro_vs_MBUS_Pro_front_sight_comparison.html