NEED HELP WITH A VORTEX SCOPE

[AverageJoe]

Did you enter the correct elevation and pressure or did you use the default which is sea level?

[10Turkeys]

It used to be that most drop charts were put together with the scope 1.5 inches above the center of the bore, don't know how they figure it now, I use the did hit method on all my rifles. Don't know about now but most scope manufactures were pushing a very large objective lense, with the pretense of more light capability, which sounds great but your eye will only take in so much light so that is bs and coupled with the fact that you had to use higher rings to mount the scope which did nothing but pull your head off the stock to see the cross hair. If you look at most scopes that are designed for competition you will find them between 30-40mm. Just my opinion and that is like everything else everyone has one.

[lancetkenyon]

For measuring true scope mounting height above bore, you will need a micrometer, or a tape measure at least.

 

Measure your bolt diameter and divide by half (bolt diameter is .700, so .350")

Measure your scope tube diameter and divide by half (scope tube is 1" so .500")

Measure the distance between top of bolt and bottom of scope tube. Say .750" for example.

 

Add these three measurements together.

.350"

.500"

.750"

 

1.600" would be scope height above bore. This is an example, you will have to take your measurements and do the math.

 

As for barometric pressure, without a Kestrel or rangefinder that gives a reading, it would be difficult to determine. You can get some weather apps that will be close too, but might not be exact. Barometric pressure can make a big difference in ballistics. It is like changing elevation a couple thousand feet at times.

[AverageJoe]

Barometric pressure changes same as elevation changes. The higher the elevation the lower the barometric pressure.

 

This is a chart of true barometric pressure per altitude

 

Altitude. Pressure

 

1000 28.9

 

1500 28.3

 

2000 27.8

 

2500 27.3

 

3000 26.8

 

3500 26.3

 

4000 25.8

 

4500 25.4

 

5000 24.9

 

6000 24.0

 

7000 23.1

 

8000 22.2

 

9000 21.4

 

10000. 20.6

[lancetkenyon]

Not necessarily true when weather factors in. I have noted 29.90 to 27.85 at Ben Avery. Not that 100 or 200 yards makes much of a difference, maybe 1/2", but longer shots can be drastically effected.

[vinniebeeks]

 

 

watch this video it should help you.

[STOMP442]

The way to measure scope height as outlined in applied ballistics for long range shooting is this. Measure the dia of your scope bell and divide by two. Measure the dia of your barrel at the end of your scope bell and divide that number by two. Then measure the distance from the bottom of the bell to the top of the barrel and add them all together to get your scope height. Most scopes with 50mm objectives end up being at least 1.8 if not a bit more. That all depends on scope design and ring height.

[AZ_SAWBUCK]

Well I got her dialed in! I met with a buddy and shot through a chronograph. Turns out that my zero for elevation was way off some how. I also ended up switching to a heaver bullet, 180 gr. Federal Fusion.

 

The bullet Chronographed at 2991 fps. So I took this info and made a new chart on the Vortex website. Laid down with a bipod and a good rest under the stock and shot decent group at 350. After a small windage adjustment I backed up to 600 and was very pleased with my group. Those WT bucks don't stand a chance in 24B next week! Thanks for all the suggestions your input really helped!

[lancetkenyon]

2.5" group at 600 yards (assuming a 1" square on the bold lines)? You are golden. Nice shooting. Get a big one!!!

[Mocha1545]

You Look good to go now! Looking forward to the story of your big buck!