CASV on TM M4

Folks - if I mount a CASV rail forearm on a TM M4, how much room is left on the original top rail for BUIS? I have a cut-down carry handle rear BUIS. Will that still fit or will I have to get a lower-profile rear BUIS like an ARMS#40?

[bruce]

It will still fit if you don't mind having the cut-down carry handle sight stick out beyond where it's suppose to end. Dirty Deeds uses this method on his CASV M4. But it's really designed for an ARMS #40.

Thanks Bruce. I expect I'll throw an ARMS on it shortly then.

For the record, it doesn't fit. The CASV I mean. I tried one of the cheap chinese versions and it just won't go on.

[Shooting Chef]

I have a Vltor CASV on my M15 but I have to do some minimal filing to get it to fit on right. If you want to see a pic pm me and I'll shoot one off to you.

It seems as thought there's no way in hell the rear ring is going to fit on the delta lug. Even with the delta ring OFF, it wouldn't mate in the right place.

[Godlyspartan]

What CASV kit did you buy? Seems cheese if it has fitting issues. On my casv kit i didnt have to do anything to fit it on a Tm m4.

[mcguyver]

Having used the King Arms CASV on several occasions, I can tell you that it fits the real steel barrel nut as well as Systema and G&P with no problems. It would not fit the ICS very well at all, and Marui uses a similar nut on their M4.

If you had an aftermarket nut and outer barrel, likely you would not have this issue, but stock Marui with that stupid split nut/ring arrangement leaves alot to be desired for fitment of accessories like that. The ARMS SIRs fit the same way that the CASV does.

ARMS #40 as well as the clones like Samurai and Action are the best fit for the CASVs that I've used.