Looking for opinions on using the KAC 600m BUIS, as oposed to the 300m, as a BUIS with an Aimpoint.

Reasoning: the Aimpoint is great for CQB and, I would assume, good to 100m or so.  So instead of having a BUIS that mirrors this distance, why not utilize the 600m sight?  In this way, I'm thinking, the BUIS can serve in a greater capacity than as simply a if-you-ever-need-it sight; you could use it to enhance the capabilities of the weapon in addition to and with the Aimpoint.

Perhaps I am over-estimating the abilities of the KAC 600 (I have never used one).

As always, your opinions are valued.

The KAC 600m sight has a small aperature only.  If your Aimpint fails in CQB I would not want to be stuck without a large aperature in close confines.  Why not use a cut carry handle instead?  You get faster transition to the large aperature irons and still get the 300-600m adjustments with the small aperature.

You could always use the aimpoint housing as a Large aper. @ CQB distance. It will ghost out & be accurate enough in close. Use the 600 for back up? "the BUIS can serve in a greater capacity than as simply a if-you-ever-need-it sight;" Isn't that why they call it a back up; There if you need it.-Justin

For what its worth (and to each his own), Marine Force Recon uses that setup:

[img]http://www.forcerecon.org/Photos/DeepRecon/perellaiadrill.jpg[/img]

[url]http://www.forcerecon.com/strongmenarmed3.htm[/url]

The 600M BUIS is basicly useless with a M4. Your not going to be able to put anything down at that distance with that weapons system It was dropped from the SOPMOD project for this reason.  

I agree, a 14.5 inch barrel is good for about 250 to 300m, anything pass that is shot in the dark or you just got to be very very good.  Marine always love to go for the long range shot, this is also why the A2 sight can be adjusted as far as it was request by the Marine corp.  I would stick to a KAC 300m if you like the design or in my opinion, the ARMS #40 is the best BUIS on the market.

Thanks for the insightful replies.




What I was thinking about was using the 600m [i]in conjunction with[/i] the Aimpoint; i.e., using the Aimpoint for close stuff and flipping up the 600m for distance shots, rather than only using the BUIS if the Aimpoint were to fail.

I am thinking that PSYWAR1-0 may have it right, however; my M4gery may not be of great use beyond 300m, so perhaps I may stick with the 300m sight, or go to the ARMS 40 - there must be a discussion comparing these two somewhere - anyone wanna help me out?

The ARMS 40 is vastly superior to the KAC 300m sight.  The KAC 300m sight is the worst iron sight you can use if you have to use it but it is the lightest.

ARMS 40 Spring loaded means it cant get knocked down
ARMS 40 Has small and large aperatures

KAC 300 has nothing to keep it up so it can be knocked down
KAC 300 has a small plastic insert to make the large aperature a small one

You would use the small insert to sight in the backup sight then put it away as you will lose it in the field.  This means you ONLY have a large aperature for 50-200m and no small aperature for 300m like the ARMS 40.

ARMS 40 is less expensive too.

Feedingcannibal,I have 5 different types of BUIS.I have a LMT cut carry handle,a ARMS 40A,a KAC first generaton 300m,a KAC second generation 300m and a KAC 600m.Of them,all but the KAC 600 are strickly BUIS.I never plan on using them unless the optics go down.The KAC 600m on the other hand is more like a second sight system.If I fell like chalanging myself I might take off the scope and use the BUIS.As for the others I prefer the KAC because it is completly out of your vision.The ARMS would be second and the LMT last.On the other extreame if your primary sight went down in tthe middle of something nasty the LMT would be the best because you dont have to flip any thing up.I say go with KAC 600m and have fun.How often are you going to need a BUIS?You can do what I did and spend a lot of money for nothing.SJR556.