Need help... Or advice

[ElevenBravO]

So I got my Vltor Casv El in the mail yesterday (Woo hoo!) And put it on my Bushmaster C15 upper, mounted my AIMpoint and Matech BUIS. Today I bought a CMMG 16" upper receiver this morning from a fellow Calgunner. So I dismounted everything from my C15 and put it on the CMMG. Everything fit except for my Matech BUIS. On the C15 flat top, there is an extra space for mounting which fit the BUIS, but the CMMG doesn't. So now I can't mount my Matech cause my Vltor is mounted as well, not giving it enough room to mount my BUIS. When these are mounted on my C15 upper, everything fits perfectly cause of that extra space allowing to mount the BUIS. So what should I do? Sell my Matech? Or buy/trade another BUIS that would fit? If it came down to buying or trading, what BUIS should I get? I hope this didn't confuse any of you. I'll try to post pics from my phone to get a better image of this. I don't have a camera and I'm posting this through my phone. Thanks for the help

[AndrewMendez]

You confused the hell out of me!! But you got a free bump out of it!

[xm177]

Clarify which Vltor product is causing a conflict. Normally any clear flattop upper should be fine w/the Matech BUIS. If you don't like the Matech, consider the Troy Rear Battlesight, LMT Tactical Rear Sight, or LaRue's Tactical BUIS. All all excellent options.

[Arteel]

Its not fitting because there aren't enough slots leftover with the Vltor.

How many slots does the Matech use? I've seen people use the A.R.M.S. BUIS with the Vltor with no problems.

Clarify which Vltor product is causing a conflict. Normally any clear flattop upper should be fine w/the Matech BUIS. If you don't like the Matech, consider the Troy Rear Battlesight, LMT Tactical Rear Sight, or LaRue's Tactical BUIS. All all excellent options.