moa bases do I need them

[Thumper1991]

Picked up an vortex he 4x16x44 today for a good deal. I see it has 75 moa adjustments. I'm shooting an 7mm mag at 2880 with .617 bc . Right now I'm out to 500 yard with mildots. But I'm wanting to dial. Will I need a 20 moa base out to 800 or 1000? 800 will probably be about my max but eventually I'd like to get out to 1000. But thats another topic

 

[Eaglet]

Picked up an vortex he 4x16x44 today for a good deal. I see it has 75 moa adjustments. I'm shooting an 7mm mag at 2880 with .617 bc . Right now I'm out to 500 yard with mildots. But I'm wanting to dial. Will I need a 20 moa base out to 800 or 1000? 800 will probably be about my max but eventually I'd like to get out to 1000. But thats another topic

Thumper1991,

With your set up at an altitude of about 5000 ft Elev. you should be able to shoot
at around close to 1200 yards just using the turrets and without using a tapered
base.

With a 20° base you should be close to 1500 yards.

 

[Thumper1991]

Thank you for your reply. I do usually shoot around 5000 ft. And hunt 5 to 7500. Thanks again. My program just didn't seem right. But you confirmed what the strelok was giving me.

 

[FEENIX]

Bruce puts it best ...

Originally Posted by bruce_ventura View Post
Even though the scope adjustment range may be large enough to get to 1,000 yds, you should use a 20 moa base. That's because off-axis optical aberrations that degrade resolution increase with incidence angle. You should set up your rifle so that the incidence angle is minimized for long distance shots (where resolution matters most).

Assume the base is within +/-10 moa of alignment with the rifle bore. Let's also assume your bullet drops no more than 30 moa at 1,000 yds, and you like to zero your rifle at 100 yds. With a standard base, you would need up to -40 moa of adjustment to get to 1,000 yds. That means you need a total 80 moa of adjustment.

With a 20 moa base you would need up to -20 moa to get to 1,000 yds, but up to 26 moa to get to a 100 yd zero (worse case boresight alignment in each case). That means you need a total 52 moa of adjustment. With a 20 moa base, however, the incidence angle at 1,000 yds is 20 moa less, so the image will have less blur.

Good luck and happy safe shooting/hunting.

Ed

 

[RCrem700]

I have the same scope, also on a 7 rm, and mounted on a 20 moa warne tactical base At 1000 with a 300 yd zero your load should be dropping just over 21 moa. that is well within the range of the scope, so you dont really need the 20 moa base, but it will come in handy if you ever want to go farther. my setup gives me about 56.5 moa of adjustment past my zero. theoreticaly (i've never shot past 1000 yet) that should be enough to get out to about 1650yds.

 

[WildRose]

No you don't need it. I use Zero MOA EGW HD bases on most of my rifles and they work great. Len sells them and the TPS TSRW rings that I use through the LRH store.gun)

 

[mountainman56]

I have a Vortex HS long range 4-16x44, the same caliber rifle and it sounds like we are shooting the same bullet. I do have 20 moa bases but I can shoot to 1200 yards at 2600 foot altitude with only 25 minutes of elevation. You should be fine out quit a bit further than that.