Results 1 to 10 of 10
  1. #1
    Join Date
    Sep 2014
    Location
    Texas
    Posts
    5,854
    Downloads
    2
    Uploads
    0

    Settinig up an optic for long range

    Hopefully you guys can read through and provide tips or advice for something I might be missing. I am game planning (or window shopping) for the optics portion of a rifle that will ultimately be used for long range. Depending on the rifle in question I am looking at 1,400 to possibly 2,000 or so yards give or take some depending on other components.

    The optic I have in mind is the Vortex Razor Gen II 4.5-27 FFP.

    https://vortexoptics.com/vortex-razo...x_reticle=1500

    For the mount I have a choice between various Spuhr mounts. The first one is a 20.6 MOA mount.

    https://spuhrwebshop.com/en/isms/sp/34/6/

    The other is a 30 MOA mount.

    https://spuhrwebshop.com/en/isms/sp/34/9/

    Currently those are my tentative options or something to save towards.

    On the Spuhr site, the instructions say to measure the outside of the front bell housing and divide by two. That scope has 2.55" listed as the spec for that dimension so divided by two it gives me 1.275 as a minimum height. Rounding up the 1.5" high mount(s) should be about right. That should be fine and will give me some clearance hopefully.

    For the 20MOA vs the 30MOA the instructions say don't use more than 50% of the allowable scope adjustment. The optic has 71MOA total adjustment, which I would assume if mounted on a zero base mount would be zeroed at or near the middle of that range for a 100 yard zero. 71 divide by two=a theoretical 35.5 MOA allowable adjustment (assuming that it had a native zero exactly half of the total adjustment range).

    If I choose the 20.6 MOA scope mount it would allow me to have a total of around 56 MOA dial capability (if the zero was truly half of the total adjustment).
    If I choose the 30 MOA scope mount it would give me right around 65 MOA dial capability, once again assuming the zero was near the center of the adjustment range.

    Now, if I use the reticle for hold overs, that would give me +36MOA more on top of those numbers hence the 20 MOA mount for example would give me a total of 92 total MOA available... which in my opinion is more than enough for how much real estate I have access to. It would give me enough adjustment to go where I want to go with several calibers for long range stuff. (6.5 CM, 6mm etc)

    All that said this leads me to think that one of the two options below for a scope mount would be about right for AR patterned rifles.

    https://spuhrwebshop.com/en/isms/sp/34/6/qdp-4616.html

    Or the non cantilever version...

    https://spuhrwebshop.com/en/isms/sp/34/6/sp-4616.html

    I am guessing that based on my previous experience the scope pushed forward like that gives me better eye relief in an AR patterned rifle.

    I also think (Maybe) that I could actually get into two (the 6ARC and 6.5 CM) sought after calibers by being able to swap the scope until I could get another or make up my mind for something else.

    Long story short with this kind of setup I would dial up (some) and then use the reticle for the rest.

    Anything to add? Bueller? Am I missing anything?

  2. #2
    Join Date
    Sep 2014
    Location
    Texas
    Posts
    5,854
    Downloads
    2
    Uploads
    0
    In theory I could even put that kind of optic set up on my .22LR rifle and be able to practice some long range dial up and hold over connections in my yard. Hence another +1 for the cantilever version.

  3. #3
    Join Date
    Nov 2013
    Location
    Seattle, WA
    Posts
    2,070
    Downloads
    0
    Uploads
    0
    I always use cantilever mounts on AR-15s. You don't always need the cantilever for large frame ARs as the receiver is longer, but I think a cantilever gives your flexibility.

    I recommend you check out the Bobro dual lever mounts, too. You get an awesome QD setup and support a veteran owned American business


  4. #4
    Join Date
    Nov 2013
    Location
    Seattle, WA
    Posts
    2,070
    Downloads
    0
    Uploads
    0
    And note below how far forward the optic is even in a cantilevered mount. I don't like having to extend my stock too far so generally I never want the ocular lense behind the charging handle


  5. #5
    Join Date
    Sep 2014
    Location
    Texas
    Posts
    5,854
    Downloads
    2
    Uploads
    0
    Interesting! Very nice rifle. What caliber is it chambered in?

    I am not set on the brand of the mount hence the thread to see more options and to get feedback. I will definitely keep Bobro on the list.

    On that rifle pictured which model of optic is that and since it's zeroed how many clicks to do you have until you max out the elevation (from your zero)? [This is one thing I am still curious about and I am sure it's different for each rifle but it should give me a ballpark number to work with]. I assume your scope mount is zero MOA/Mil but let me know for sure.

    I was thinking the same thing about the cantilever vs non cantilever. I mounted a couple of scopes on various rifles and for an AR it seems like the cantilever is the only way to go.

  6. #6
    Join Date
    Nov 2013
    Location
    Seattle, WA
    Posts
    2,070
    Downloads
    0
    Uploads
    0
    Rifle is .308. Glass is the 3-18x50 model. Looks like I only needed 3MOA up to zero. Yes, 0 MOA base. Honestly, I haven't shot it past 200 yards yet. The reticle (which is awesome, btw) has holdovers up to 36 MOA in elevation which is pretty much 1,000 yards with 175gr SMK, so I doubt I'll ever use much of the mechanical elevation. No need for built in cant in the mount in this platform / caliber.

    With good scopes and good rifles, you really shouldn't have to move too far from the scope's mechanical center for a 100 yards zero. I'd be a little upset and concerned if I needed much more that 5 or 6 MOA in either windage or elevation to zero. If you're cranking 10,15, or even 20 MOA in to zero then something is off mechanically with the rifle, the mounting system, or the optic. A $50 TruGlo, sure, but not a $2,000 piece of glass on a $2,000 rifle. Lapping the upper frequently helps.

  7. #7
    Join Date
    Sep 2014
    Location
    Texas
    Posts
    5,854
    Downloads
    2
    Uploads
    0
    Quote Originally Posted by BoilerUp View Post
    Rifle is .308. Glass is the 3-18x50 model. Looks like I only needed 3MOA up to zero. Yes, 0 MOA base. Honestly, I haven't shot it past 200 yards yet. The reticle (which is awesome, btw) has holdovers up to 36 MOA in elevation which is pretty much 1,000 yards with 175gr SMK, so I doubt I'll ever use much of the mechanical elevation. No need for built in cant in the mount in this platform / caliber.

    With good scopes and good rifles, you really shouldn't have to move too far from the scope's mechanical center for a 100 yards zero. I'd be a little upset and concerned if I needed much more that 5 or 6 MOA in either windage or elevation to zero. If you're cranking 10,15, or even 20 MOA in to zero then something is off mechanically with the rifle, the mounting system, or the optic. A $50 TruGlo, sure, but not a $2,000 piece of glass on a $2,000 rifle. Lapping the upper frequently helps.
    I am actually trying to induce that 'move from mechanical center' so to speak. I enjoy pushing the limit of something beyond normal use. I shoot my 16 inch AR out to 800+ I think the farthest I've scored hits was 900. In order to get those sometimes stupid amounts of dial up/hold over combos a 20 or 30 MOA scope mount would have been very helpful. That basically has me cranking down to get to zero, which leaves a lot more room to go up when I try some of the other things that run through my head.

    I have long wanted a 6.5 creedmor and now I really want that 6 ARC but the past little bit I haven't been able to splurge a ton on more new stuff. [That said I just bought almost $2K worth of more cans]. Getting the money together to build an upper is not really the issue, but spending much bigger dollars on optics is a lot more expensive especially if you are talking for multiple guns. I've tried to be pretty financially disciplined to be honest but hopefully the stock market will continue to be really nice to me. If I meet certain self declared goals I allow myself to peel off some cash as a reward. It's a motivation so to speak.

    With that 6 ARC that is putting the long range part into real attainability for me in more than one way. The optic set up is by far the most cash. I figure with certain (currently available) bullet selections I could get out to 1,400 yards with that. Maybe longer but it depends on the optic and other factors. Once I get into that (assuming all goes well with that caliber) I can shoot that a lot more than say a .338 Lapua or some other monster.

    My longest target is at 1,400 but if I take the 1,000 yard plate and turn it and shoot a different firing angle, over the top of the lake, we can get out well over a mile. I think it's over 2,000 yards actually. I've taken other people shooting numerous times with various guns... 300 RUM, 338 Lapua, 308 etc but I want my own 1,000 yard ++ gun and basically for the cost of an upper I think that's definitely a reality now, assuming that I get the optic to be what/where I want it set up as.

  8. #8
    Join Date
    Sep 2014
    Location
    Texas
    Posts
    5,854
    Downloads
    2
    Uploads
    0
    The good thing about the setup and optic/mount combo described above is that at least in theory I could use that optic in more than one scenario. I could in theory drop it on my current 22LR rifle and based on my calculations it would be good past 400 yards for some rimfire ELR action. I already have the rifle just not the optic...

    I could also possibly build or buy a 6.5 Creed either in an AR platform or bolt action. The 6.5 might be a bit more but I could live with that, and hopefully by then I can get another optic or whatever.

    If the stock market is really REALLY nice to me that's another story all together, but for now I am figuring out how to get into all this stuff without harming myself financially in the long term.

  9. #9
    Join Date
    Mar 2013
    Location
    The Unfree State (MD)
    Posts
    2,731
    Downloads
    3
    Uploads
    0
    Name:  03796EAE-FDE9-46B6-A0F0-5E28455040DD.jpeg
Views: 138
Size:  1.66 MB

    SP-4902 with a optic that has a 50mm objective. I would definitely recommend the extended mount as you can see without a stock with a extreme LOP like the PRS you quickly run out of room.

  10. #10
    Join Date
    Sep 2014
    Location
    Texas
    Posts
    5,854
    Downloads
    2
    Uploads
    0
    Quote Originally Posted by SINNER View Post
    Name:  03796EAE-FDE9-46B6-A0F0-5E28455040DD.jpeg
Views: 138
Size:  1.66 MB

    SP-4902 with a optic that has a 50mm objective. I would definitely recommend the extended mount as you can see without a stock with a extreme LOP like the PRS you quickly run out of room.
    Rifle looks great! I think I pretty much have an idea what I am after now. Your rifle there pretty much says a lot about how things 'working together' matter.

    I'm not stuck on that one specific scope that I mentioned earlier, but the general idea is there.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •