Rifle Scopes Scope Re-zeroing for multi-caliber rifle setup

[TangoSierra916]

Hello fellow Hiders,

For those of you who have/have had a rifle like the AI AXMC, DT, Remington MSR or other multi-caliber systems and used the same scope for all calibers, how do you change zeros/manage different zeros for swapping calibers?

I know some scopes are easier than others to change zeros, with and without tools, curious if you:
- shoot and re-zero per caliber every time you switch caliber
- document the difference from caliber 1 to caliber 2 , then adjust zero without shooting, tighten turret down and rock n roll
- other methods?

If you could provide what scope you're using and what your experience has been as far as swapping calibers on the same rifle, that would be great, thank you! Really looking for what optics users have experience with, how you manage the different zeros and changing and if you've had issue/inaccuracies due to a certain optic.

 

[TangoSierra916]

Scopes either track,or they do not.

I'm loathe to pull rail/rings/glass if forced to change a spout(I'd much rather have another complete rifle,than fuck around),but denoting Ele and Windage corrections in the fray is hardly disconcerting.

Cite the particulars of your platform(s).

platform is AXMC with .308, 6.5cm, 300WM and 338LM calibers.

 

[mojavejim]

I document my Zero with the longest life barrel for my AI. Then track the difference between it and the others, usually I can set up my scope when switching barrels & then confirm. Most AI barrels are repeatable +-.1 mil.

 

[TangoSierra916]

I document my Zero with the longest life barrel for my AI. Then track the difference between it and the others, usually I can set up my scope when switching barrels & then confirm. Most AI barrels are repeatable +-.1 mil.

thanks for the response, which scope do you use?

 

[SRPowah]

DT SRS. I zero'd for the "home" barrel which is 6.5CM. My 2nd barrel is .300wm and consistently .2 up, .2 left. I just factor in that offset when dialing. Kahles 624i, S&B US, and now a NF 4-16 ATACR on it. Dialed for all of them.

If I remove and reinstall the same barrel over and over, the POI change is so minimal that I can't shoot well enough to tell. I can routinely put 10 round groups under .8 moa with factory ammo.

 

[Sixfivesavage]

I am currently only running two barrels, a 6.5 creed and a short 308. I'm zeroed on a K318i with the 6.5 barrel because that's the primary barrel. I wrote down the offset of the 308 barrel with a sharpie on the barrel in front of the hand guard on top. Swap the barrels and the offset is right there, I dial the offset and run it. So far it's working out. Hillbilly I know, but it works for me. I very rarely if ever dial anything anyway so I don't have to keep track of anything in the kestrel or worry about messing up dope.

 

[mojavejim]

S&B PMII

 

[TangoSierra916]

DT SRS. I zero'd for the "home" barrel which is 6.5CM. My 2nd barrel is .300wm and consistently .2 up, .2 left. I just factor in that offset when dialing. Kahles 624i, S&B US, and now a NF 4-16 ATACR on it. Dialed for all of them.

If I remove and reinstall the same barrel over and over, the POI change is so minimal that I can't shoot well enough to tell. I can routinely put 10 round groups under .8 moa with factory ammo.

thanks for the response, so you dial and extra .2 and .2 for the 300wm, that works!

 

[MACHTECH]

Tango,

I own or have owned 4 different switch barrel platform systems. DT, AXMC, Kraken and Ritter and Stark. Take a look in the Cadex section at the review I did on the kraken. The Cadex is the only system that is pretty much 100% POI repeatable on barrel swaps. The AI and DT are very close, but can be off by up to .3 mils on a switch with the same barrel going out then back in. The R&S tried to solve this by adding a rail and separate scope for each barrel. We see where that got them. The best way I have found to re-zero after a swap is to have a target up at the 100 yard line and just take a couple shots first, then re-zero the turrets. That's why I love the TT scope for switch barrel platforms. I hope this is the info you were looking for. This is just my opinion, but it's honest!

 

[TangoSierra916]

Tango,

I own or have owned 4 different switch barrel platform systems. DT, AXMC, Kraken and Ritter and Stark. Take a look in the Cadex section at the review I did on the kraken. The Cadex is the only system that is pretty much 100% POI repeatable on barrel swaps. The AI and DT are very close, but can be off by up to .3 mils on a switch with the same barrel going out then back in. The R&S tried to solve this by adding a rail and separate scope for each barrel. We see where that got them. The best way I have found to re-zero after a swap is to have a target up at the 100 yard line and just take a couple shots first, then re-zero the turrets. That's why I love the TT scope for switch barrel platforms. I hope this is the info you were looking for. This is just my opinion, but it's honest!

I appreciate the response, I understand the switch POI change, wishing it was 0. lol

 

[TangoSierra916]

What/when/why would "mandate" a barrel change on the fly?

Could be a hunting shot, maybe I start with 6.5cm at the start of the day but see an animal at a distance where I want more terminal ballistics at greater distance, switch to the 338lm on the fly.

This gets into “ethical shots” and how each shooter defines “mandate” as well.

 

[TangoSierra916]

So you schlep the Outdoors with a quiver full of barrels on your back,waiting to Robin Hood a "victim"...as per your Estrogen Levels?

Oh my.

Haha no just two barrels 6.5 and 338. Just providing a what if scenario but I always was a Robin Hood fan. Lol

 

[GIXXER2000]

I have the original AI-PSR and the reputability is very good I swap barrel between 300wm, .338LM and 33xc and and had no issue with my zero. I set the zero for the .338lm and the 300 wm is + .2 mils and the 33xc is -.1 mil. One thing i think helps is all my barrels were spun up by Dave Tooley and when i do my part are 1/2 moa or better. When it comes to Multi barrel rifles the only other i would own is the Cadex Kraken. I did take a long look at the DTA but its just not for me don't like the bull-pup design. I also have an AI-AT and have no issues with zero when swapping barrels.

 

[Bradu]

I don't have any of my barrels recorded for the offset. They are close enough to hit a target so I shoot one round and use the reticle to measure what I need to dial. I am sighted in in three rounds. I have the zero stop set for the barrel that has the lowest setting. I probably should record it but I've never taken the time to note the changes since I would prefer to do it for all the barrels for that rifle in the same day

 

[TangoSierra916]

I don't have any of my barrels recorded for the offset. They are close enough to hit a target so I shoot one round and use the reticle to measure what I need to dial. I am sighted in in three rounds. I have the zero stop set for the barrel that has the lowest setting. I probably should record it but I've never taken the time to note the changes since I would prefer to do it for all the barrels for that rifle in the same day

That works for sure, thanks for the response. Which scope do you use?

I’m sort of debating a scope with a built in zero stop similar to he Razor gen 2 or one you can change like the atacr.

 

[Bradu]

ATACR and Nxs for them.

 

[_Windrider_]

That works for sure, thanks for the response. Which scope do you use?

I’m sort of debating a scope with a built in zero stop similar to he Razor gen 2 or one you can change like the atacr.

You don’t need to re-zero when you change calibers. It’s actually really not that difficult. Zero your optic with the flattest shooting projectile you will use. Then without adjusting your zero start changing barrels and documenting the offset to your zero. So if you zero with a 338 and a 285Berger for example, when you switch to 6.5 your zero might by off by .3. You can now adjust your DOPE for the different calibers. A ballistic solver is very helpful here as well as a scope with a zero stop. Don’t over complicate it by changing your zero. Just gather the DOPE and adjust from your baseline zero of whatever you use.

 

[TangoSierra916]

You don’t need to re-zero when you change calibers. It’s actually really not that difficult. Zero your optic with the flattest shooting projectile you will use. Then without adjusting your zero start changing barrels and documenting the offset to your zero. So if you zero with a 338 and a 285Berger for example, when you switch to 6.5 your zero might by off by .3. You can now adjust your DOPE for the different calibers. A ballistic solver is very helpful here as well as a scope with a zero stop. Don’t over complicate it by changing your zero. Just gather the DOPE and adjust from your baseline zero of whatever you use.

I appreciate the response, heard a few suggesting the same. So basically with your example you’re saying when I go to 6.5 and with a .3 difference in DOPE yould just account for the .3 with adjustments and. Not rezero? So .3 is really .6 in that example

 

[_Windrider_]

I appreciate the response, heard a few suggesting the same. So basically with your example you’re saying when I go to 6.5 and with a .3 difference in DOPE yould just account for the .3 with adjustments and. Not rezero? So .3 is really .6 in that example

Yes but to clarify I’m saying zero with 338. Then switch to 6.5 and without dialing anything shoot. Document the diff between the POA and POI. In my example the 6.5 would be .3 low so you dial up .3 and voila you are now zeroed for 6.5 at 100. So when shooting the 6.5 and you want to come back to your zero you stop at .3. .3 up from zero is the new zero.

This is also one reason why many shooters set the zero stop at .5 past the actual zero. Some shooters will zero the scope at the caliber they shoot most often and then sometimes you have to dial up or down when you switch to be zeroed at 100. The point is you have to know what the zero offset is and understand that maybe with a 6.5 you might be dialing 9.6 at 1k but you are actually only shooting 9.3 because of the offset.

Does that make sense at all?

 

[TangoSierra916]

Yes but to clarify I’m saying zero with 338. Then switch to 6.5 and without dialing anything shoot. Document the diff between the POA and POI. In my example the 6.5 would be .3 low so you dial up .3 and voila you are now zeroed for 6.5 at 100. So when shooting the 6.5 and you want to come back to your zero you stop at .3. .3 up from zero is the new zero.

This is also one reason why many shooters set the zero stop at .5 past the actual zero. Some shooters will zero the scope at the caliber they shoot most often and then sometimes you have to dial up or down when you switch to be zeroed at 100. The point is you have to know what the zero offset is and understand that maybe with a 6.5 you might be dialing 9.6 at 1k but you are actually only shooting 9.3 because of the offset.

Does that make sense at all?

Yes Im tracking with you, thanks for the responses.

 

[Long Range 338]

I've got the same setup and am running a Tangent Theta. Just as Dillhole mentioned, my zero stop is set for the 338LM barrel and I have documented the barrel offset for the other barrels in my ballistic solver. I also think a hard copy attached to the rifle or scope somehow would be a great idea, I just haven't come up with a good way to do it yet. I simply change the barrel and dial my offset, most of the barrels are not more than .3 offset anyway. I just dial so I can use the center of the reticle for point of aim, I don't reset the zero stop.

If somebody comes up with a great way to document this and have it on the rifle, I'm all ears as well.

 

[Long Range 338]

What/when/why would "mandate" a barrel change on the fly?

Because, America! Seriously go piss on a thread somewhere else.

 

[TangoSierra916]

I've got the same setup and am running a Tangent Theta. Just as Dillhole mentioned, my zero stop is set for the 338LM barrel and I have documented the barrel offset for the other barrels in my ballistic solver. I also think a hard copy attached to the rifle or scope somehow would be a great idea, I just haven't come up with a good way to do it yet. I simply change the barrel and dial my offset, most of the barrels are not more than .3 offset anyway. I just dial so I can use the center of the reticle for point of aim, I don't reset the zero stop.

If somebody comes up with a great way to document this and have it on the rifle, I'm all ears as well.

With TT isnt the zero stop set at .5mil under the zero mark or can you adjust that? I like the approach you've both mentioned.

Because America!!! AMEN!

 

[_Windrider_]

I've got the same setup and am running a Tangent Theta. Just as Dillhole mentioned, my zero stop is set for the 338LM barrel and I have documented the barrel offset for the other barrels in my ballistic solver. I also think a hard copy attached to the rifle or scope somehow would be a great idea, I just haven't come up with a good way to do it yet. I simply change the barrel and dial my offset, most of the barrels are not more than .3 offset anyway. I just dial so I can use the center of the reticle for point of aim, I don't reset the zero stop.

If somebody comes up with a great way to document this and have it on the rifle, I'm all ears as well.

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[Long Range 338]

Yes the TT gives you .5 below the zero stop. If you have one barrel that you are going to use most of the time, you might want to do the initial setup for it. It really doesn't matter if you wanted to rezero every time as the TT makes is very easily done. I can see myself setting the zero stop for a different barrel than my default and then forgetting which one it is set for.....(a clear indication of more time spent doing multiple load development than just shooting, or something other than good training time). For this reason I leave the zero stop set for the 338LM barrel and also all the other barrels are come ups to zero at 100 yards. I know in similar threads the Razor2 was mentioned as being easy to rezero as well.

 

[Long Range 338]

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Please, do not tempt the gear whores....

 

[Downtown]

Different situation, not sure it's relevance. I put together three Marlin lever actions. One in 45 Colt, 30-30, 45-70. Same Luepold Scout scope, same XS rails, quick release mount. Have notes that just say this number down, this number over, etc., for each caliber. Figure that set up allows hunting most everything. I was suspicious how well it would work, but it exceeded my expectations. A small adjustment might be made between scope changes, but not necessary for hunting accuracy.