MOA forward Cant base

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rxpat762

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I understand that a forward cant in a base, for eg 20 MOA, allows you to zero at an extended range. Is there a commonly accepted range that would be referenced when deciding to go from a zero Cant to a forward Cant base?
 
rxpat762 said:
I understand that a forward cant in a base, for eg 20 MOA, allows you to zero at an extended range. Is there a commonly accepted range that would be referenced when deciding to go from a zero Cant to a forward Cant base?
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It depends on the trajectory of the round shot, and the amount of vertical adjustment in the scope. The flatter the trajectory and the more adjustment in the scope, the less cant required. 1/4min click scopes usually have more adjustment than 1/8min.

Many .308's with 1" scopes require cant to reach beyond 800 yds.

NormB
 
See, i went with a base instead of the burris rings an di dont regret it. I also use a burris scope with enough elevation that i wouldnt need it, but i use it anyways. I dont regret dishing the cash either
 
The Burris system (we carry them as well) is fine, but for heavy duty use, the solid tapered base and solid rings cannot be beat.
 
When I went to school 1 degree=60 minutes, not sure what the new math is like:p
1/4 degree would be 1/4 of 60 minutes or 15 MOA.
 
Depends on the scope and your rifle zero.

First shoot your rifle and best load at 100yds dead on to POA. how much up elevation is left in the scope? If there is more then enough to go as far as you want, no need to worry about shimming scope.

If you run out of elevation, then calc how much more you need and shim accordingly.

example, you have a 308 and want to go to 1000yds. Guesstimate is 40min for most ammo. Your 100yd zero leaves you with 45 min of up elevation. Good to go.

You have 30 min of up elevation left. Shim a min of 10min. However, be aware that if you go with a 20min base, you may create a much higher zero at 100yds then your scope can now compensate for. A bit of trial and error.

That is why I like the Burris rings. You can change the amount of shim available from 5 to 30min by swapping inserts. You can also center your scope so less windage is needed. This will help with elevation tracking and amount available.

The quality of new production Burris rings is superb. The hardware is very strong and the quality/durability/grip of those inserts is fantastic. They also eliminate any scope marks and will not allow your scope to be bent by an out of whack action (surprisingly common).

The new 30mm rings have the more common 4 cap bolts, increased in size and are very strong. I have seared torx wrenches without putting a scratch on the bolt. Not sure where they get their hardware but it is the best I have seen.

I also use canted bases WITH the Burris rings as I enjoy shooting a very long ways.

Most flat shooting cartridges can go a very long ways on internal scope adjustment alone. Just put some info into a ballistics program to see approx how much 'up' you will need to make the trip.

A 7RM shooting 162gr AMax only takes 23 to 26 min to go from 100 to 1000yds. Really depends on what you shoot and how far you want to go.

Jerry
 
Craig67 said:
If you had a 20moa base, would you be able to shoot from 200 yds out to 1000 yds ?

Or could you only shoot from say, 500 to 1000 ?

Craig
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That would depend on how much internal adjustment you have on the scope.
Where on the adjustment your 200 yard zero is.
What caliber you are shooting.
 
Craig67 said:
If you had a 20moa base, would you be able to shoot from 200 yds out to 1000 yds ?

Or could you only shoot from say, 500 to 1000 ?

Craig
Click to expand...
Good question Craig67.

With a rifle set for a 100M zero, crank the adjustment all the way clockwise, counting the clicks, bringing the scope to its lowest bullet impact limit. This will, roughly, tell you how much of a sloped base you can use and still be able to return to zero at 100M. Crank it all the way up, counterclockwise, while counting the clicks and you will know how much travel you have remaining for long range. Now you can decide what to do about a sloped base. However, changing from a flat base to a sloped base may get you more or less than desired, depending on how true the bases are in the first place.

Edited to remove repeated sentence
 
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Thanks for the info everyone, I'm new to the precision rifle thing, still waiting on the tax return so I can get into the game.

I'm going with a Savage 10 FLP in .308 and a Bushnell 3200 series 10X40 mildot scope. I'm still having trouble figuring out what rings and bases to use. Its down to the TPS rings and bases or the Burris Signature set up.

Guess I'll keep thinking about it :)

Craig
 
Good choice I have the same scope and love it. Something about bushnell's magnification adjustment ring pleases me and a good bang for the buck. Leupolds dont get me wrong are nice but i guess i am on the bushnell bandwagon, and Mr. Zeis is a little rich for my blood. Oh and thank god for the Block hopefully they go through with supporting the budget otherwise its back to the poles
 
Craig67 said:
If you had a 20moa base, would you be able to shoot from 200 yds out to 1000 yds ?

Or could you only shoot from say, 500 to 1000 ?

Craig
Click to expand...


Most scopes have at least 20MOA internal adjustment so adding an additional 20 minutes of taper shouldn't affect your ability to hit up close. I have 20 MOA tapered on all my rifles and they are fine for the odd time I shoot under 300M

Use any free on-line ballistic calculator to plot the amount of drop you will have at any distance and any increment of distance. This will help you figure out if your scope can handle it.
 
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