Do these rings provide enough clearance for this scope?

[morfeeis]

So i ordered a Burris Fullfield II 6.5-20x50mm scope after talking myself out of a Banner and a Viper. I've never had a 50mm scope that i can remember and i'm sure I've never put a 50mm scope on an AR. So for my SPR will i be able to get away with the medium scope rings that clear .50 or will i need the high rings that come in at .75?

Scope
Rings


Thanks.

[Merc1138]

Get the outside diameter of the scope bell (B) http://burrisoptics.com/scopespecs2.html

Cut that in half to get the radius.

Since it's a 1" tube and you're using 1" rings, use the radius for that since it's still in the center of the scope(it's 1/2" btw).

Add 1/2" to the ring height measurement. Convert to mm. Verify that this number is greater than the radius of the objective end of the scope.

1. lay a straight edge across scope base extending over barrel where objective will land
   
2. 50mm = 1.97" [let's say 2"] = 1/2" lower than a 1" main tube
   
3. compare the difference and adjust ring height accordingly

That doesn't quite work since the actual outer diameter is 63mm, not 50mm. He needs to clear roughly 1.25". The high rings will do it(but not if his handguard sits taller than the rail on the receiver). But with the AR you've got a different issue to contend with(not really a problem for the OP). On an AR the comb of the stock is so high compared to the top of the receiver, you usually need pretty tall rings anyway.

edit: Also, if you plan on adding some slip on lens covers like butler creek or something, you need to include those in the outside diameter of the objective end of the scope as well.

[Merc1138]

just thought about that.. bell dimensions would vary..

my 50mm on my m82a1 is 2 3/16"

about 3/32" over on height which is little consequence in my 35mm ring options..

known bell dimension would be most accurate..

Yeah, that's why you gotta head to the optic manufacturer website.

[morfeeis]

Thanks guys.

[vintagedude88]

Keep in mind that you'll also need additional clearance for the caps. Especially if you plan on using flip-ups. I've had situations where I had just enough clearance for the scope but not quite enough for the cap.

[G21Shooter]

The Burris PERP mount should work fine, if you have the money get the LaRue LT104.

[morfeeis]

Keep in mind that you'll also need additional clearance for the caps. Especially if you plan on using flip-ups. I've had situations where I had just enough clearance for the scope but not quite enough for the cap.

I thought about that , the cover I will be using is like a sock that covers the the whole scope.
Its made by Burris so it should be fine but thanks for the forward thinking. It would suck if I bought the flip up covers and they didn't fit. I know the end of the scope is threaded for a sun shade so I could find a screw on cover for it , but what about the peace part( yes I know my terminology is all wrong ,sorry). Is that section threaded too?

The Burris PERP mount should work fine, if you have the money get the LaRue LT104.

I'd love a better mount but that will have to wait till later. I told my wife my budget was $ 500 that mount would end up costing another $500 if you get my drift.

[Merc1138]

I thought about that , the cover I will be using is like a sock that covers the the whole scope.
Its made by Burris so it should be fine but thanks for the forward thinking. It would suck if I bought the flip up covers and they didn't fit. I know the end of the scope is threaded for a sun shade so I could find a screw on cover for it , but what about the peace part( yes I know my terminology is all wrong ,sorry). Is that section threaded too?

I'd love a better mount but that will have to wait till later. I told my wife my budget was $ 500 that mount would end up costing another $500 if you get my drift.

Sun shade will typically thread to the inside of the bell end of the scope. It shouldn't increase the outside diameter. Unfortunately, the odds of finding lens covers made for those threads is probably pretty slim unless burris happens to use the same threading as another company that does have threaded lens covers available.

However even a scope coat(had one that came with a leupold) will still need to fit around the outside diameter of the bell.

Regarding the burris pepr(I have one as well), it's hight in relation to the rings you posted, is 1"(A in the diagram). I would suggest getting the 1" rings(actually I'd also suggest just getting the pepr, the non-qd version is cheaper, and it comes with a set of tops without the stupid rails).

Normally on a rifle you want the scope as low as you can get. However with an AR, you have a problem since the stock sits so high thanks to the buffer tube, that you WILL need pretty tall rings. Even ignoring the clearance issue of the objective lens end of the scope, you still need to get the ocular lens(the part you're looking into) high enough so you can actually look through it.

[shooterbill]

The medium rings will be fine. I ordered the high rings for my 50 mm scope and they are too high.