Scope Rings Height

[Ranger61 0]

A new 7.62X39 owner as you can tell. I ordered and will receive this week the 5th Gen UTG side mount. I have decided on a Buriis FullField II 2X7 scope (not yet ordered),and a set of Burris Signature rings. What height rings do I need (low, med, high)? I've just about setlled on medium,but am not sure if this would be right or not.

 

I have no conversions to the rifle, and am not sure if there will be any. I've searched for this particuliar issue, but either I'm not skilled enough to find it, or there's none to be found. Thanks!

[Thor88 3]

Using low rings, I had an issue with the scope not clearing the rear sight .

 

I would recommend at least medium, I would definitely make sure you can exchange the rings for the next size up in case they are too low.

 

Hope this helps.

[Ranger61 0]

Using low rings, I had an issue with the scope not clearing the rear sight .

 

I would recommend at least medium, I would definitely make sure you can exchange the rings for the next size up in case they are too low.

 

Hope this helps.

 

 

Yes, that helps tremendously. I had fears of what you just described and I thank you.

[jbrubaker 13]

I bought UTG Low rings off Amazon and am able to clear a 44mm front objective on my front sight. It's a Konus Pro scope with 1" tube. I have to force the cap on because of the small amount of clearance, but it fits and the low rings provide a good cheek-weld for me. My two cents.

[Ranger61 0]

And I appreciate that two cents...It's worth more than that to me.

[Rhodes1968 1,638]

The rings must place the scope a bit higher(I use 10mm or 2/5 inch for reasons listed below) than half the objective size at the highest point of possible contact.

This assumes of course that the objective is the widest point of the scope extending downward, cant see it being otherwise.

 

For a 40mm objective the rings must place the point where the rings contact the scope tube higher than [20mm(half of objective) - X(half the scope tube diameter either 1/2 inch,13mm) or 15mm for those 30mm tubes)+10mm(clearance mentioned)] above, in this case, the rear sight plane. For a one inch tube 40mm scope this comes to 20-12+10=18mm, of course higher is ok.

 

If you are using a side mount dont forget the height of the mount. I find it better to measure than rely on assumptions and trial and error.

Also a side mount requires the objective to clear several inches of the rifle since it slides on to the bracket from the rear. During mounting if it clears everything that is fine only the final clearance matters for use. So for example if your mounting surface is 5mm higher than the plane of rear sight using the results above [18mm-5mm = 13mm or about 1/2 in. at the rings] (that would be a medium set of rings IIRC) as long as it clears the rsb the highest point on the rifle when sliding on the mount.

 

Recoil will beat a scope to death if it doesn't have enough clearance(more critical the longer the focal length) since there is some flex, just getting it to barely clear may not be enough. Many scopes are blamed for breakage when frankly it was hammered every time the rifle was fired because the objective was so close to contacting the rifle. (look at slow motion video of an AK firing) Thus the additional 10 mm for clearance.

I use much tighter clearance for my Marlin boltie btw, much less flexing going on there.

 

Thats what I do, YMMV. All these numbers are just examples. I seem to remember Midway may have video on the subject on youtube.

 

Of course just really to make life easier you want the scope as close to the plane of the barrel as possible and theres that cheek weld to consider

I always use my framing level and metal ruler with the rifle locked down to make all the measurements. Yeah engineering school leaves scars.

 

And that friend is everything I have ever read or experienced on the subject and you may consider it much ado about nothing.

If wrong I do hope someone corrects me but this has saved me a few trips back to the store for rings and even some battered scopes.

 

Midway video

Edited July 7, 2011 by Rhodes1968

[Ranger61 0]

Tremendous amount of information Citizen. I have printed your statement out in order for me to absorb it all at my leisure. Good video too. Thanks!

[Rhodes1968 1,638]

Not a problem if you see any changes need making let me know.

I had been meaning to do write up for a note book on the care and feeding firearm I am putting together for my son who lives too far away for more personal instruction. Hadnt done this subject and there was the excuse opportunity.

A few drawings would help.