40MOA Bridge

[ARIZONA_F_CLASS]

Is anybody else using a 40MOA bridge for a dedicated 1000 yard and above rifle. I have been using one because I wanted to be as close to the center movement of the scope. Only bad thing is when I, for some reason have to shoot at 300 yards. I'm 4" high with the scope bottomed out.

Is it really necessary??

 

[cdparker]

Personally, on my F-Class guns, I use a 20MOA base. That being said, I think that a little math would be in order. Take the total elevation that your scope is capable of moving. One half of that is where your scope is supposedly parallel with your barrel and should be close to a zero at 100 yds. +/-. So, if you add a 40 MOA base, at what range would you have to zero to be centered in the X? I have the adjustable rings on my Barrett 98B. What I did was to crank the elevation knob down to it's stop and come up 1 minute. Then I adjusted the rings so that my elevation was really close at 100 yards. Lock the rings and zero my gun at that range. Slip your knobs to zero and set your stop. Now I am zeroed really close to where my scope is centered at distance. Run the numbers on your cartridge, pick a zero distance that is compatible with your local range. Take the ballistic program information for 1000 yards. That should get you pretty close to the slope of the base you should be using to get to where you want to be. Does that compute?

 

[ARIZONA_F_CLASS]

Thanks CDPARKER,

The max on my scope is 48 MOA and I come up 29 MOA with the 40 MOA bridge. From what I figure From a true 300 yard zero I would come up 34 MOA

So I could probably get away with the 20MOA base. But there is a range in Commiefornia I like to play at that goes beyond a mile. Haven't shot that far yet. But I think I might have enough scope. I also have two mid range guns.

 

[Keith Glasscock]

34 MOA is huge for 300 - 1k.

What bullet and velocity? I successfully used a 20 MOA base for F/TR with 200 and 215 grain bullets. Neither took that kind of elevation.

 

[Erik Cortina]

What is a 40 MOA bridge?

 

[Dos XX]

If the bridge were a mile long, it would be a bridge that was 61.42 feet higher on one end than the other. ;D

 

[Erik Cortina]

If the bridge were a mile long, it would be a bridge that was 61.42 feet higher on one end than the other. ;D

That's what I figured, but how do you use it for shooting? Maybe in a tactical scenario where you want to have a good view of the field.

 

[cdparker]

Arizona- Just for the fun of it, Please list what you are shooting. Cartridge, bullet, and your MV. What scope are you using? A lot of what you posted does not compute. The guys who are answering you are very wise and will be a good source of information.

 

[Old Navy]

Had plans last summer to try one mile with my 6X47 Lapua benchrest rifle. My 12X42 Nightforce does not have enough elevation built in with a 20 MOA base to get there. Put on a 40 MOA. Had plenty then but cranked all the way down I was shooting 27" high at 100. The one mile never happen. Some one set up a bunch of bee hives at my firing line. Maybe this summer.

 

[Old Navy]

Opps! Just noticed how old the thread was. Sorry!

 

[Downeast]

Without bringing back the dead I just installed a 40 Moa mount last night on my 6.5 CM. I "upgraded" to a "NightFarce" Benchrest (12X42) and I run out of elevation at 400 yards. I'm going to go out this morning and see what happens. It's zeroed at 300 yards. With my old Burris XTR I had no problem keeping it in the 10 ring at 600 yards.

 

[dsinfour]

If want to try a mile you will need a 40 minute bridge rail but no farther than 1k the 20 will work fine and you will have a 200 yds. target. Later

 

[243BR]

Without bringing back the dead I just installed a 40 Moa mount last night on my 6.5 CM. I "upgraded" to a "NightFarce" Benchrest (12X42) and I run out of elevation at 400 yards. I'm going to go out this morning and see what happens. It's zeroed at 300 yards. With my old Burris XTR I had no problem keeping it in the 10 ring at 600 yards.

Just want to make sure I understand. Are you saying the with the nightforce and 0 MOA base you ran out of elevation at 400 yard?

 

[Downeast]

I had a 20 moa rail and I ran out elevation at 300 yards. Well, I had one moa of elevation left. I took everything off and reset everything with the same results. So I added a 20 moa set of rings to the rail which now gives me 40 moa total. I just came from the range and I'm sighted in at 300 with 2.5 moa of down elevation remaining.So I might be able to sight in at 200 yards. I haven't done the math.

But I can dial up from New York to Los Angeles.

This is a brand new and my first NF scope. Not really that impressed. I think my Burris has clearer glass. I was using 12" Shoot-n-z targets and the little numbers were not as crisp and easy to read as they are with my Burris at 300 yards.