Site Notices
7/29/2014 4:02:36 PM
7/28/2014 11:40:43 AM
Author
Message
semperserveranceSTA
Offline
Posts: 21
Feedback: 0% (0)
Posted: 1/2/2012 11:44:49 PM
[Last Edit: 1/2/2012 11:48:09 PM by semperserveranceSTA]
When using an optic/scope is the measured height over bore from center of objective lense to center of inside diameter of bore? When using isnipe ballistic app this is a question asked so Id like to be as precise as possible.


Psalms 91
SharpCharge
Member
Military
Offline
Posts: 3132
Feedback: 0% (0)
Link To This Post
Posted: 1/3/2012 12:55:35 AM
Use a straight edge or a caliper. A few fractions aren't going to hurt.
semperserveranceSTA
Offline
Posts: 22
Feedback: 0% (0)
Link To This Post
Posted: 1/3/2012 2:36:09 AM
The measuring is not the problem basically what I'm asking is what is the exact definition of sight-over-bore ... Point A is what and Point B is what
tumbleweed
fuego antipático
Offline
Posts: 3083
Feedback: 100% (7)
Link To This Post
Posted: 1/3/2012 2:48:53 AM
The definition is center of objective to center of bore. Use a machinists rule, measure from center of scope tube to the bottom gas hole in the bolt carrier. That will put you in the strike zone.
The only fool bigger than the person who knows it all is the person who argues with him. Stanislaw Jerszy Lec
Desert_AIP
I always get the shakes before a drop
NRAMilitary
Offline
Posts: 7600
Feedback: 100% (37)
Link To This Post
Posted: 1/3/2012 2:50:55 AM
center of objective lense to center of inside diameter of bore

A - center of objective lense
B - center of inside diameter of bore


KC-10Boom: Cookies should never give one the shits.
pavlovwolf
Member
Online
Posts: 5935
Feedback: 100% (7)
Link To This Post
Posted: 1/3/2012 3:45:57 AM
Most optics on the AR flat tops are about 2.5 inches. It's a good rule of thumb, and any ballistic calculator will be very close within a half inch. It's close enough that the difference in the ballistic app is going to need to be field tested anyway at distance to confirm and adjust, since no app is perfect.
Don't go ninj'in nobody that don't need ninj'in
bp7178
Offline
Posts: 95
Feedback: 100% (21)
Link To This Post
Posted: 1/3/2012 9:32:13 AM
Holding a ruler isn't the most precise way by a long shot.

The measurement is centerline of bore to centerline of the scope's rings.

If you know your scope mount height and height of the upper's rail over the bore, you can add the two together.

A Vltor MUR's rail is 1.215" over the centerline of the bore.

A Larue SPR 1.5 has a ring height of 1.5".

So, this combination will give you a HOB of.....2.715".
SuperSet72
Member
Offline
Posts: 1742
Feedback: 100% (59)
Link To This Post
Posted: 1/3/2012 10:28:54 AM
I agree with BP's measurements.
semperserveranceSTA
Offline
Posts: 23
Feedback: 0% (0)
Link To This Post
Posted: 1/3/2012 10:32:38 AM
Thanks y'all I got brain injury from fallujah so I don't know what I'd do with out y'all! I'll be paying my member fee I think
pavlovwolf
Member
Online
Posts: 5953
Feedback: 100% (7)
Link To This Post
Posted: 1/3/2012 10:39:26 AM
Originally Posted By semperserveranceSTA:
Thanks y'all I got brain injury from fallujah so I don't know what I'd do with out y'all! I'll be paying my member fee I think


Thanks for your service. There is a lot of info, and fun on this site. You need a thick skin sometimes though.
Don't go ninj'in nobody that don't need ninj'in