Is there any difference between the 50c bi level slimline and the 46c slimline other than that front rail being the same height and uninterrupted all the way to the front sight post on the 46?
Are they actually 2 different units or the same with the 46 having the extended hi-rise front rail where the 50 has a low or sunken in one?
I need to either swap the front rail for the bi level effect of the 50 or trade my 46 for a 50.
Thanks in advance and merry X-mas

While the real guy to answer this question is MSTN (on the EE) IIRC, the #50 was designed for use of the EOTech on the foward lower portion of the S.I.R., whereas the #46c was just a re-make of the #45 in a "slimlined" version.

Mike

I had some questions about the SIR as well.

If I have a RRA M4gery and I use an Aimpoint, which one should I get, the 46 or 50?

I was thinking the 46, since I already have the "mod spacer" on my ARMS 22M68.  It appears that if I get the 50, that'll be too high (or I'd have to take out the spacer).

I have 46C, but you probably would better off with 50C if you aren't interested in PEQ-2.

My origional plan was aimpoint or eo-tech (remaining neutral)on the top rail, with an AR2A front sight mounted laser and M900 underneath.
The front rail will be unoccupied with that setup, or I keep the 46 and put an OTAL in front of the ML2 instead of the front sight mount.
Opinions would be appreciated.