Drawbacks of scope cant and 1k yard zeros?

[Yerman]

I’m building a 300 Norma Magnum and looking to take her out to 3000 yards on occasion. Most of my shooting will be around 1700 yards to 2500 yards but I will likely play with 3000 yards + when the conditions dictate.

I’m still undecided on my optic but I’m looking hard at ZCO, ATACR, Kahles, Minox, etc.

When I do finally decide on an optic, I’ll want to make sure I get a capable mount that lets me take full advantage of the scopes travel, and the more I think about it, the more I’m leaning towards significant cant in the scope and a long range zero to compensate for it.

My Defiance action will have 20moa built into the receiver, and I’m leaning towards something like a Spuhr mount with 18mil (61.8 MOA) built in. Obviously, I wouldn’t be able to get a 100yard zero so what are the disadvantages to going this route and just setting my optic for a 500-1000yd zero?

Aside from not have a close zero, I can’t find a reason this wouldn’t be a good idea.

Also, I’m not 100% convinced in adjustable bases like the Era-tac because I’m not convinced they lock up solid, and the Charlie Tarac is out of my budget. Let me know what you guys think. Thanks.

 

[diverdon]

I think if that is the setup you want then you should not let let what we think stand in your way.

 

[CoryT]

The only downside is a zero that has more 'float', that is, it changes a significant amount as conditions change. If your software accounts for that, (like FFS) or you don't mind walking in shots rather than going for cold bore hits, it's not a real problem.

 

[Yerman]

The only downside is a zero that has more 'float', that is, it changes a significant amount as conditions change. If your software accounts for that, (like FFS) or you don't mind walking in shots rather than going for cold bore hits, it's not a real problem.

Interesting thought. Just so I understand...I suppose you are saying the with a 100 yard zero, environmental changes don't necessarily change the POI on your zero at such a short range, but they come into play at 1000 yards. So unless you have a ballistic solver that accounts for your zero environment at long range zeros, you are going to be fighting a loosing battle every time. That makes sense. Unfortunalty, my Kestrel 5700 doesn't take zero conditions into account.

What is the go-to solution right now for dialing that much elevation (40-50 mils)? Pretty much an adjustable base or a Charlie Tarac?

 

[IntoTransonic]

No, but you can use a 100 yard zero with a zero offset measurement plugged into your app.

For example, my zero offset is exactly 10.625” 10-5/8” high at 100 for my cheytac. The difference between TN and Raton, NM is minimal...minimal at 100 yards.

 

[CoryT]

The TARAC is the hot ticket, the zero offset method will also work with some programs.

 

[Esoteric Junkie]

The ERA-TAC adjustable mount is rock solid and repeatable.

 

[b6graham]

era-tac or charlie tarac, good idea

1000y zero, not a good idea

 

[47chevycoe]

Tell me if I’m wrong, but a 300 Norma only drops about 5.5mils at 1k. So if you’re zeroing your rifle at 1000 instead of 100, you’re only gaining 5.5 mils of scope adjustment.

 

[b6graham]

JBM puts a 230 Hybrid at 3,000/fps at 6.4mil, 59 degrees standard baro at sea level

 

[Bradu]

The 215 shoots flatter at 1k according to a friend. I will be ordering a 300 norma barrel shortly to see for myself once my other barrel is done.

 

[b6graham]

The 215 shoots flatter at 1k according to a friend. I will be ordering a 300 norma barrel shortly to see for myself once my other barrel is done.

i think this is pretty common

 

[Yerman]

Tell me if I’m wrong, but a 300 Norma only drops about 5.5mils at 1k. So if you’re zeroing your rifle at 1000 instead of 100, you’re only gaining 5.5 mils of scope adjustment.

Shit. I didn’t even think about that. You’re right, it won’t help me enough.

I’m going to have to go with another solution. I guess I’m back to plan b which is an Era-tac Mount. I wish they had a mil version.

 

[47chevycoe]

Shit. I didn’t even think about that. You’re right, it won’t help me enough.

I’m going to have to go with another solution. I guess I’m back to plan b which is an Era-tac Mount. I wish they had a mil version.

I was close to making the same mistake. Not really sure which direction I want to go now...but the era tac is at the top of my list.

 

[CoryT]

Here you go

Ivey has a mil base

 

[GIXXER2000]

I have the 50 mil Ivey base works great on .338 and down. There is some issue shooting 375,408,416 and 50cal seems to have more recoil the them mount can handle.
The only down side to shooting lite 215,220 grain bullets is once you get passed 1500 yards the splash on misses can be hard to see.