Bore height for Kestrel

[Cobiwan]

I recently bought a Kestrel and am doing the obligatory trial and error learning curve for it. I wanted to know if someone could confirm the bore height of this rifle. I know, I didn't say math would be involved, but maybe someone has the answer.
MPA BA Comp chassis with .308 and 6.5 CM MPA barrels on a Curtis Axiom action with a WTA switch lug. I have a MPA 20 MOA rail, and a MPA scope mount that is 1.25" 35mm 0 MOA. My scope is a Leupold Mark 5HD 7x35x56mm.
I got 2.1" with my calipers. I think my measurement is wrong. Any help is greatly appreciated.

 

[Char'ed Cuterie]

Only you can get that measurement correct. Here's a quick and dirty way -

A) Measure the diameter of your scope tube in a section between a ring and the turrets where it is flat. Divide this measurement by 2. This is "A"

B) Measure your bolt body diameter, anywhere in the middle of it where it is straight. Divide this measurement by 2. This is "B".

C) Measure the distance between the top of the bolt and the bottom of the scope tube (same spot as A). This is "C".

A + B + C = Bore Height.


My competition gun measures out to 2.00something, my hunting rifle is 1.791, so 2.100 that you have is completely reasonable given your action, mounting, and optic.

 

[Cobiwan]

Only you can get that measurement correct. Here's a quick and dirty way -

A) Measure the diameter of your scope tube in a section between a ring and the turrets where it is flat. Divide this measurement by 2. This is "A"

B) Measure your bolt body diameter, anywhere in the middle of it where it is straight. Divide this measurement by 2. This is "B".

C) Measure the distance between the top of the bolt and the bottom of the scope tube (same spot as A). This is "C".

A + B + C = Bore Height.


My competition gun measures out to 2.00something, my hunting rifle is 1.791, so 2.100 that you have is completely reasonable given your action, mounting, and optic.

Thank you!

 

[Cobiwan]

Using that method I came up with 2.094

 

[Char'ed Cuterie]

There you go, that's what I would use for your Kestrel then.

 

[Rob01]

Here is the easiest way and it works fine with no math. Center of bolt to center of windage knob. No doesn't matter if a 20 or 40 MOA base and as long as you are within .25" you are fine. Have used this method for a long time and it works perfectly.

Or with a caliper.

 

[padom]

Here is the easiest way and it works fine with no math. Center of bolt to center of windage knob. No doesn't matter if a 20 or 40 MOA base and as long as you are within .25" you are fine. Have used this method for a long time and it works perfectly.

View attachment 7928653

Or with a caliper.

View attachment 7928654

Bingo this takes 2sec and is so easy... I use the ruler and it's always been spot on..

I took a new barrel out the other day...my new 22BR barrel.. chrono the first 15shots down the barrel at 3020 SD6.. put that velocity in my Kestrel, selected the bullet and selected AB Custom Curve for it... input my zero distance of 100yd measured with LRF, enter my barrel twist and then measured center of my scope tube to center of bolt...got 2.125" and put that in my Kestrel.. set weather to live and let that gain data for a minute then locked it...

Input 636yd and put my reticle on the waterline on steel.. dead center hit on the water line....dialed 700yd, dead center hit on a 6" swinger... g2g

I use AB CC whenever it's available and it's always been g2g for me..

 

[Baron23]

Here is the easiest way and it works fine with no math. Center of bolt to center of windage knob. No doesn't matter if a 20 or 40 MOA base and as long as you are within .25" you are fine. Have used this method for a long time and it works perfectly.

View attachment 7928653

Or with a caliper.

View attachment 7928654

Yeah, I use a caliper also but take the measurement at the back end of the bolt (center of the shroud, right) up to the center of the ocular len's cover . Maybe I'll try to the middle of the windage as you suggest. Looks like easy access/easy to eyeball it.

 

[KineticPerformance]

I use the same method as Rob and Dom. Any time I need to measure the scope for a firing solution, I measure to the centerline of my turret.

 

[Mike Casselton]

Stealing Rob's image, you can just measure this if you're shooting a Remington action.

That's about as easy as it gets.

 

[SweaterDood]

FYI - if ring height is stated by the mfg, it is a measurement from the top of the pic rail to the centerline of the scope tube, regardless of tube dia.

You can measure from the center of the bolt/action to the top of the pic rail (centered over the port), and add the specified ring height. This can be useful if changing ring height or swapping scopes on a. You can also get the jaws to center on the FP hole in the bolt, and touch to the pic rail this way.

 

[Rob01]

Or just measure to the center of the windage knob and be done with no math.

 

[SweaterDood]

Or maybe entertain a different way of doing things. No need to repeat yourself.

 

[Rob01]

Or maybe entertain a different way of doing things. No need to repeat yourself.

Yeah I will entertain a way that is more work. That’s always the best way. Why do it an easy way that works when you can do it a more complicated way to get the same answer. Lol

 

[kriller134]

Yeah I will entertain a way that is more work. That’s always the best way. Why do it an easy way that works when you can do it a more complicated way to get the same answer. Lol

Work harder not smarter

 

[OREGUN]

Holy shit. Leave it to the hide to make a dumbass easy measurement into a math problem and then resurrect the thread a year later to argue about it.