I get asked this question semi-regularly – which then often leads to a discussion about MOA vs MILS – as there is still a persevering idea that MOA only works with Yards and Inches and MIL only with metric measurements.
The whole, MOA vs MIL is a different debate again – and relevant only if you intend to dial your scope in the field. If you are planning on ‘setting and forgetting’ your rifle scope – like I pick 99% or hunters do – then it really is irrelevant.
I am hunting up close. I don’t plan on dialing.
Ok. So this is going to be quick.
In short, zero at whatever range you have available. Then stop thinking too much about it and go hunting.
If your local range is 100 meters – all good – if it’s 100 yards – also all good. The difference between the two on a practical level is going to be so small it’s going to get lost in the act of shooting in the field, while lying over a rock and tree, breathing heavy and trying to deal with buck fever. If you can only get 90m, or 83.7m out the back of the farm before you head away, then that is also all good.
The difference between a 100m and 100y zero, in terms of ‘MOA’ – which most hunting scopes come in – is going to be under one click. That (roughly, with rounding) equates to less than a 1/4 inch change. How big is the target you are shooting again? While I encourage everyone to understand what is going on here, I also encourage everyone to also understand that we shouldn’t get lost in the minutia of detail. It’s mental masterbation.
If you plan on shooting (generally) 100 meters (or yards) and under – i.e. bush hunting then you are overthinking this. However. Make sure your rifle is zeroed properly. It sometimes scares me how far out (I am talking meters) that some guns are. You get away with this at a 30m bush hunting setting – though – it think it might also account for some of the close-up gut shots people still seem to make. You need to know and be confident in your knowledge, of where the rifle is shooting.
However, if you are considering the odd shot out to, say, 200 meters or yards, you might want to consider a walk, or ‘point-blank zero’. This allows for a point and shoot method that allows the ballistic curve to account for a target being closer or further away.
I want to shoot further. I want to dial.
So. 100m and under – just zero and go. 200m and under – consider an MPBR setup, beyond 200m, can I please, please suggest it’s time to start understanding how all this stuff works, property, and set up the gun, and yourself properly to maintain an ethical hunting practice.
Besides the point, that at 500 meters, the wind is going to kick your arse if you have never shot in it, there is no way you should be simply holding onto the animal, or even guestimating how high over the shoulder you need to be aiming. So you need to develop, test and validate ballistic charts – then dial to use them in the field (things like the CDS dial or custom scope turrets also work well here!).
If you are planning on learning and using ballistics, then yes, it becomes important to know exactly where you are zeroed. However, the unit it’s done in, provided the data entered is correct is matching, doesn’t really matter. If you zero the rifle at 101 meters, then load that into the ballistic calculator and it will calculate based on that. If it’s a perfect 100 yard zero – then load that in. Most systems will let you decouple the input and output units. I.e. you could zero at 100 yards, then have the dial information and distances outputted in MIL or MOA and the distances in yards, or meters. This is dependent on the ballistic calculator itself. I would again, also suggest, if you want to shoot animals to distance – you should know, and understand all this. While it’s cool to be able to rely on technology to do all this, part of that is understanding how it works, primarily to ensure you have it set up right in the first place.
Related to this – I ask clients when I am setting up their rifles – if they want the charts in meters or yards. This generally relates to what their rangefinder is set up in. This again is really up to you – and I would suggest there are a few people who are simply using whatever their unit came in – because they don’t know how to change it.
I get people to tell me how far way the nearest house is – they respond in meters or yards, depending on what they normally think in – and I generally suggest that they work in the same format as that. We should be looking for simplicity in our setups, not additional layers of conversion if we don’t need it.