Jerry-B-WI
5 year old buck +
Depends how much drop you have at 100 and 200 yds. A good reloading manual should have charts in the ballistics section for your caliber, bullet weight, and velocity.
Rifle Range Upgrade
- Thread starter yoderjac
- Start date
Foggy47
5 year old buck +
Not exactly sure of the angle you got going here.....but minor angles wont make an appreciable change in your ballistics. Shooting in the mountains will have an effect.
Jerry-B-WI
5 year old buck +
Give that to me in degrees along with some ballistic info and I could look it up in one of my reloading manuals. I'd need caliber, bullet weight, and bullet speed in fps.
Foggy47
5 year old buck +
Unless your 20 degrees or more and over 300+ yards.....it's not gonna make a huge difference for hunting purposes.
yoderjac
5 year old buck +
Keep in mind, most shots in the field are not level. If you hunt from a tree stand, close shots are at a pretty steep angle. Terrain plays a factor as well. Folks looking for long-range accuracy typically sight in on the level at 200 yards. Many range finders have an inclinometer and a ballistic calculator built in. Once you have entered your ballistic data, you can get both an actual range and ballistic range for your target.
If you are concerned about accuracy, I wonder if you could use such a range finder to set your target at the ballistic range of 100 or 200 yards. I'm not 100% sure this makes sense, but it is something to consider. Regardless of the angle, there is certainly a target distance that is equivalent to 100 or 200 yards on the level. This would let you use this safe area to place your range. The key is figuring out the right distance for target placement.
yoderjac
5 year old buck +
Yep. Angle can matter at shorter ranges only when it becomes extreme. One good example is bowhunting, but the same can apply to a rifle. There are two factors at play. First is simple geometry. If you range a deer from a tree with an old range finder, you are ranging the hypotenuse of the triangle. If you sight in your bow at ground level, the "ballistic range" of your arrow will be shorter than your range finder told you. (newer range finders can correct for this). The old and easy solution was to range trees from your stand at stand height rather than ranging the animal itself. That would give you the ballistic distance based on a ground level sight-in.
The second factor that comes into play is the one Froggy was describing. In bowhunting we call it parallax. The same holds true in rifle hunting, but parallax is usually used in that context to refer to the focal plane of the cross-hairs (parallax adjustment on a scope). Now think about shooting a deer just a couple yards from your stand that is 20' high. The line-of-sight from your eye, through the peep, thru the pin, to the deer, is quite a bit higher than the arrow (even more so than a scope over the bore center on a rifle). Froggy described the general process with a scope over the bore. With a bow it is just more extreme. It turns out, you end up needing to shoot long distance pins for very shot distance shots.
A few degrees of angle ends up being negligible, but when you get more than 45 and begin approaching 90 degrees things become extreme and it matters. Similarly, negligible error caused by small angles become significant at very long range shooting.
Thanks,
Jack
b116757
5 year old buck +
For a 6.5 Creedmoor a 10 degree angle changes POI by 4” at 1000 yards so unless you’re shooting long range the angle is meaningless your angle looks to be about 1.5 degrees. Don’t waste your time worrying about the angle correction for your new range.
First chart is 0 degrees
Second chart is 10 degrees
First chart is 0 degrees
Second chart is 10 degrees
Attachments
Foggy47
5 year old buck +
The NRA used to publish a firearm fact book. One of the more interesting tidbits in that book had to do with bullet drop. If you fired a level gun at waist height with a bullet that traveled 3000 fps and at the very same instant dropped a bullet at the same height.....which would hit the ground first? The answer is they would both hit the ground at the same time. Gravity has the same effect on a given weight regardless of how fast it's going (ok....there are some minor differences in practice). Physics is interesting stuff.
I wonder if I still have that little book? Should pass it on.
I wonder if I still have that little book? Should pass it on.
Mortenson
5 year old buck +
To the experts, can we safely sight in a 350 Legend at this spot? My camera is on the table. The orange star is 100 yards out, probably a few feet downhill, and where we'd put the target. The crest of the hill on the horizon is probably 150 yards beyond the star, and call it 30' higher in elevation. Ground is frozen. No buildings beyond the hill for a few miles, but there's road about a mile away. Should be fine right?
yoderjac
5 year old buck +
My only concern would be what is behind the first rise, if there really is one. It is hard from me to tell if land rises to the skyline or if there is a dip right behind the tree line. I'd ask where it is possible for someone to come down between the first and second ridges unseen. There is still probably a safe way to do it. We have a few trails that someone could use to approach our range unseen. We put ropes with orang flags and warning across those trails when the range is hot. You may have to work out some similar mechanism. The only other issue I see is a an accidental discharge when the firearm is at an upward angle. That is no more risk than field usage. If you have the ability to build an earthen backstop, that would add a margin of safety as well.
Having said that, If you think it through, I would not see that area as problematic. Keep in mind, I'm no expert, but I have been a RSO in different places. Without being on site, it will be hard for anyone to provide a definitive answer, but from what I can tell with the picture, it looks reasonable.
Thanks,
Jack
Wind Gypsy
5 year old buck +
Less than 1' of error in horizontal distance @ 200 yards in that situation, which means you're less than 6" off on horizontal distance @ 100 yards where one should be zeroing a centerfire rifle. I doubt you're shooting anything where there is a meaningful drop between 99.83 yards and 100 yards. That's well within typical error of a range finder.
