Just double checking the pros and cons of the ARMS #40 (which comes highly recommended) vs. the KAC 300 sight (assume one gives the insert a toss to the parts box or at least the buttstock).

KAC 300
Lower profile (which is why looking at it)

ARMs #40
* Larger rear aperature (possible)
* Spring loaded
* Has 2.5 ranges (counting 500 meter notch as a half)
* Fits the cut out on the ARMs #19s ACOG mount
* Lower cost
*Appears stronger to side pressure (have not tested


Anything I missed?

I have both and they look to be the same size in the QCB peep.
Good shootin, Jack

KAC fits in the same spot so there is no advantage to the shape of the 40 with the 19S.  I like the 40 more.  40 is faster to get up in a hurry.

Have not tried the KAC 300, however, noticed the KAC 600 appears to force the the #19S to be mounted one notch foward of where others can mount their ARMS #40.

For use with Aimpoints & Eotechs the faster flip up of the ARMS#40 (plus the extra appearature) appears to make it nearly a shoe in.  However, for mounting under higher mag scopes the KAC 300 (or KAC 600 if you can live with only a small apperature or have it drilled for an insert ... yet to be tried) has some advanges in lower height.  The speed of being put up is not IMO as much of an issue as you have to take off you scope (be it a Leupold or ACOG).