What you take as shooting fact – may be fiction. Click and read to find out if you’ve been duped by these long-standing false truths. Then, go tell your friends and look smart.
The effect of wind on your bullet down range has more impact than the wind at your muzzle. Right?
Incorrect. Ok, before you start throwing your tomatoes, we’ll admit, the effect of wind on bullets is one of the hottest and most debated shooting topics – even by true experts. We’ll also admit this myth may not be entirely debunked. Now, I’m going to ask you to think of it like this. With most things attempted in life, it’s best to get off to a good start. This goes for your bullet too. The wind at your muzzle will be the first to affect your bullet – and will essentially point your bullet right or left. By doing this, your bullet is now essentially on an un intended vector. Barring being blocked by an obstruction – and therefore giving you a false reading – the wind at your location is the most critical. Will the wind it encounters through it’s time of flight effect it? Certainly – but not as much as what’s happening at your shooting position.
The lower your scope-over-bore height, the better for accurate long-range shooting. Right?
Incorrect. Take this example: Nobody complains about their custom rifle in an XLR chassis costing $5,000 (plus) dollars with a scope-over-bore height of 2.5 in. Why? Because it’s a hell-of-an-accurate and extremely effective long-range set up. In fact, no matter what a person spends, scope-over-bore height has little impact on accuracy/down-range performance at longer distances.
Now, depending on the rifle, it may have a dramatic effect on cheek weld, comfort and optimal sight picture, (which could impact shooter performance) but that is completely unrelated. Also of worthy note, scope-over-bore height should be accounted for in short-range scenarios (under 50 yards), due to the more dramatic angular relationship between the bore and the optic.
When we compared two identical 6.5 Creedmoor setups using a ballistic calculator (the only difference being scope-over-bore heights of 1.7 in versus 2.7 in.), here’s what we came up with. At 1000 yards (a distance where any deficiencies should be greatly exaggerated), the rifle with the higher scope-over-bore height required 9.13 mils of adjustment to deliver its payload on target. Interestingly .25 mils less than the rifle with the lower scope-over-bore height. One could argue the rifle with the scope mounted higher performed slightly better. Bam! Myth busted.
I need a large diameter scope tube to let in more light for better light transmission at dawn and dusk. Right?
Incorrect. Although it seems intuitive, a larger tube diameter has virtually nothing to do with light transmission. Sorry. However, it does serve a very distinct and important purpose. All things being equal, the amount of total travel a scope has is bigly determined by the scope’s tube diameter. In order for a riflescope’s windage and elevation to adjust, the internal erector assembly needs room to move within the main tube. More room to move equates to more travel. More travel allows you to dial more adjustment for longer shots.