AR-10 Large Frame Spuhr Mount with RDS Offset and RDS ... QUESTIONS

[Centuriator]

Hey guys, I'm building a large-frame AR and have some questions about the right mount to use with my optic. It's a scope 5-20. I'm considering a SPUHR mount to which I can attach a RDS at offset.

1) Should I get a Cantilever mount since it is an AR with a 12 o'clock pic rail? The eye relief on the scope is 3.5 and it is chambered for 6.5 Creedmoor.

2) What SPUHR hardware do I need to run a Trijicon RDS on it offset? I'm confused by all the SPUHR options.

3) Do I offset it to the right or left of the scope? It's a semi-auto, not bolt gun, so not sure.

4) What dot size is best for getting a quick flash sight picture with the RDS if it is needed?

THANKS

 

[newguy2k3v2]

For an rmr I believe you just need the a-0010 interface to mount it at a 45 on the front ring.
You may also want to look into a 45 mount for the receiver rail like some of the 3 gun guys run. Rather than having to break position and raise your head you just roll the rifle to line the dot up since it's about the same height over bore as the scope.

 

[Precision Underground]

Just be sure the offset mount centers the sight over the barrel when you turn the gun. It took me a week to convince my buddy that his non-centered set up was why he could not get his windage zeroed.

 

[flyer]

I like cantilever mounts but I also like a shorter LOP and "nose to charging handle" cheek weld.

Your eye relief, LOP and cheek weld will determine what works for you.

For an offset red dot sight, if you are right handed I think you want it on the right side so you push the pistol grip away from your body and roll your cheek weld over the stock to the new sight instead having your head hanging in mid air.

As far as windage adjustment goes, you just have to zero and shoot with your backup red dot centered over the bore. It's not necessarily going to be exactly horizontal with the rifle rolled over like that but as long as you can get a cheek weld and keep the dot over the bore, it doesn't need to be horizontal.

 

[Centuriator]

Thanks guys, I have ridiculously long arms, so maybe cantilever is best for me. My dress shirt sleeve length is 33-36"

Re. the RDS offset, thanks for suggestions here as well.

 

[ZeroMOA]

Here’s mine on a large frame AR (Seekins SP10)....with the PRS stock, eye relief is fine, I’m 6’3 with longer arms as well

 

[Centuriator]

View attachment 6947394
Here’s mine on a large frame AR (Seekins SP10)....with the PRS stock, eye relief is fine, I’m 6’3 with longer arms as well

Thanks, good to know. How can you see the red dot over the turret? I plan on mounting mine in a 45 degree offset.