Scope sighting, one platform with multiple calibers

[mikest]

Hello Fellow Hide Members,

Looking for guidance on the best way to sight in a rifle on a platform (such and an AI AXMC) where you can switch between multiple calibers.

In my case, I have 300 PRC and a 6.5 CM barrels and am trying to figure out the best way (if possible) to sight in the rifle on one of the calibers then switch/compensate when i change out the barrel to the other caliber without having to go through the zeroing process.

I should know the answer but could use some insight and help on the best way to think about/accomplish this (noting that I will shoot the 6.5 more often)?

Kind regards,
Mike

 

[Steel head]

Sight in for one and note the difference in the other and put the offsets in your kestrel or ballistics program.

 

[hafejd30]

I plan to do the same. AXMC with 300 PRC and 6.5.

My plan is to shoot both and zero for whichever is highest. Set zero stop there. Then note how much elevation the other barrel has to zero. Either adjust to compensate or just add into program as @Steel head suggested above. The windage can just be dialed to correct as I generally hold off the reticle anyways

Hoping the elevation won’t be to far off at 100 between the two

 

[_Windrider_]

I plan to do the same. AXMC with 300 PRC and 6.5.

My plan is to shoot both and zero for whichever is highest. Set zero stop there. Then note how much elevation the other barrel has to zero. Either adjust to compensate or just add into program as @Steel head suggested above. The windage can just be dialed to correct as I generally hold off the reticle anyways

Hoping the elevation won’t be to far off at 100 between the two

You want to zero the scope with he flattest shooting projectile that way the zero stop is set the lowest then you shoot the other calibers and note the offset.

If you do it the other way around make sure you leave .5 mils below zero then set your zero stop to account for the changes.

 

[beetroot]

As others have said, if you just note the offsets for each cartridge you have 3 different options.
-dial and reset turrets to zero
-dial zero, lock turrets and hold for all shots
-add offsets to your dope and just shoot like normal.

In practice you can use all three depending on the situation.

I'd zero the scope on the 6.5 first then free where your 300prc hits on the target in relation to the 6.5.
Set your zero stop so that it is for the cartridge that hits highest (least drop).
You can always dial higher but resetting a zero stop frequently is usually a pain.

I swap scopes between 4 different rifles and 2 barrels on one of those rifles, the max difference in elevation is 2mils so I keep the zero stop set that low.
For the most part so long as you have a zero stop set somewhere it doesn't matter exactly where it is.

 

[Ndbowhunter]

in terms of what cartridge to zero with.. go with the cartridge that is the most meaningful..

personally i dial to the known zero everytime on the switch from "go to" setup. but the go cartridge to will be referenced from bottom of mechanical zero and from right as soon as barrels are switched.

for instance my 223 shoots .7 left and 3.5 mils high compared to its 6br brother.. so when i switch i just dial down 3.5 and right .7

zero is reset on elevation. windage reads .7

but when i'm done shooting the cartridge i reference bottom of mechanical zero (11.6 mils up) (or 14.3 from top) and slip windage to zero.

2 shots touching to known zero and i'm golden.

 

[mikest]

appreciate all of the insight and guidance...