Determining Scope Ring Height

FTRRookie

FTRRookie

Regular
EE Expired
Rating - 100%
5   0   0
Location
5 minutes from Connaught
I'm trying to determine what height rings I'm going to need to order, and was hoping someone could point me in the right direction.

The scope I will be getting is a Sightron SIII 8x32-56, and it will be sitting on a Remington 700 with a Nightforce 20 MOA 2-piece base.

The rings I am looking at are TPS 30mm TSRs. From the information that I've found it looks like the low rings will work, but I'm not sure I've done the math right...

Anybody have this set-up?
 
50mm OBJECTIVES will almost always use HIGH rings in a given style. In certain instances, such as with extremely heavy barrels or some makes of firearm, SUPER HIGH rings may be necessary.
42-45mm OBJECTIVES will almost always use MEDIUM rings in a given style. In certain instances, 45mm scopes may require HIGH rings.
40mm OBJECTIVES will almost always have enough clearance with LOW rings in a given style, though MEDIUM rings will give slightly more clearance, particularly when using a barrel with a thicker shank portion or a heavier contour.
28-36mm OBJECTIVES will almost always use LOW rings in a given style. Again, in certain instances of a heavy barrel or heavy shank portion of a custom barrel, medium rings may have to be used, but LOW rings will almost always suffice.
20-24mm OBJECTIVES will almost always be able to use LOW rings, but in some cases may also use SUPER LOW rings. In this instance, bolt handle clearance of the eyepiece will come into play more so than objective/barrel clearance and should be carefully considered.
 
i'd just mount the scope on whatever rings you currently have, and find out how much excess height you have (or how much more height you'd need). then measure those rings, and get new rings that are that much shorter / taller.
 
Unfortunately I don't have any 30mm rings to try this out on.

Midway USA has an application chart that states for a 56mm objective I need .300" distance from the top of the base to the bottom of the scope tube:

http://www.midwayusa.com/content/legacy/ring_height.htm

Their description of the TPS low rings say that the low rings have a height of 0.335", which would make me think that they would work.

http://www.midwayusa.com/viewProduct/default.aspx?productNumber=244847

Am I misunderstanding something here?
 
are they basing the info on 25mm tubes? personally i find it easier to use scope centerline, since rings are split along that so in the store you can just measure it that way. but if you're only buying mail-order, you may need to give yourself more wiggle room and just pick up a somewhat taller set.

for a 56mm objective, it's probably 60mm outside diameter of "bell" so 30mm / 1.18" (half of the OD) from bottom of objective (outside) to scope centerline (this has nothing to do with tube size). what's the distance on your gun from top of barrel (which is where the objective is going to "almost touch" something) to top of weaver rail or ring mounting surface on the receiver? subtract that distance from the 30mm / 1.18" above and it should give you the ring height (assuming ring height is defined as mounting surface to scope centerline / point where ring top piece clamps on) - and if they measure it to bottom of scope hole, then just subtract half the tube diameter from it (15mm / 0.59" in your case)
 
You must log in or register to reply here.
Back
Top Bottom