Re: optic suggestions for s&w mp-15 sport
High should work fine. Might be able to see the fsp a little on 3 power, but not enough to matter. If you try to get any higher you will have to get a cheek riser for your butt stock. The real issue is whether or not u can get enough eye relief with regular scope rings. Many people use one piece scope mounts that extend the front ring over the forearm to get enough eye relief. I have used larue and American defense. I like them both. Problem is they start at around $150. Burris makes one for about $70, and nikon makes one for about $90. I personally don't care for the Burris. The nikon would probably be your best option, being that you are trying to keep the cost down. And it would match your scope. The only scope I have been able to get proper eye relief with on an ar, without a one piece mount, is an IOR. That is because the turrets are set way back near the ocular end of the scope and you can push the scope way forward. Even then, I had the scope as far forward as it would go.