rangefinding scopes question

[Willoughby]

rangefinding scopes question- the ones that show range & poi - how do they work ?
it seems they would have to know the caliber & velocity to give actual bullet drop
I ask someone who was using one -& he said it learns what ever you sight in with
obviously - all you need is money to buy one -not ballistic information
I dont want one -I just want to know how they could possibly send a 223 & a 300wm down range with accurate poi info
or for that matter 2 differnt bullet weights from the same rifle

[M.O.A.]

Might pretty sure you haveto have them programed.

I believe it pretty easy to do to and I think there only good out to 5 or 600 yards.

[helotaxi]

They have several ballistic curves programed in and you select the one that most closely matches the ballistics of the rifle that you're shooting. The Bushnell ARC model rangefinders do the same thing as far as giving you corrections.

[Opus Dei]

I ask someone who was using one -& he said it learns what ever you sight in with
obviously - all you need is money to buy one -not ballistic information

No, they don't "learn"; they don't possess artificial intelligence. And Yes, you do need ballistic information if you go with a custom turret dial. The Leupold CDS requires you provide altitude/average yearly temperature where you shoot. Then, you'll need bullet weight, coeffecient of drag, barrel length and velocity. Now, the generic BDC reticles as helotaxi mentioned work around a fairly loose set of known/assumed parameters.

Neither method is suitable for more than hunting and should be verified on POI at the reticle marks. Stuff like wind/angle/mirage cannot be factored in.

[aubie515]

Only thing close to what you are talking about is the Barrett BORS system and it's not that great.

Buy yourself a good Kestrel wind meter and get "shooter" for your andriod phone and you will have what you need...well and a good optic of course. I have a Horus reticle on my Bushnell and I like the reticle a lot for unknown distances.

[M.O.A.]

Come on guys he is talking aboul scopes like the Bushnell yardage Pro 4-12x42 laser rangefinder riflescope or Nikon's M-223 laser IRT scope or the Burris Eliminator

All scopes with built in laser rangefinder and BDC reticles

[Willoughby]

I dont want or need a RFscope
I use a mil reticle for ranging
and I use a smal 1' x 2' dope sheet on side of my stock because none of my rifles exactly follow printed data
with my own KNOWN dope sheet -using the exact load it was made with
I can mak 1st round hits with all 3 of my Savages out to 1000 yards
If I change anything its back to drawing board
2 of them are a done deal-
I have one that Im not satisfyed with yet
I was just curious how well any other system could work
thanks for the responces

[handirifle]

He doesn't care what anyone else wants or needs or likes. He isn't getting one, just wants to know how the freakin things work. I think helotaxi gave the best response.

[helotaxi]

No, they don't "learn"; they don't possess artificial intelligence. And Yes, you do need ballistic information if you go with a custom turret dial. The Leupold CDS requires you provide altitude/average yearly temperature where you shoot. Then, you'll need bullet weight, coeffecient of drag, barrel length and velocity. Now, the generic BDC reticles as helotaxi mentioned work around a fairly loose set of known/assumed parameters.

Neither method is suitable for more than hunting and should be verified on POI at the reticle marks. Stuff like wind/angle/mirage cannot be factored in.

If you look at the new Burris, it doesn't use a BDC reticule, it actually gives you a specific holdover in the form of an illuminated dot on the vertial stadia line of the reticule. I don't remember if it accounts for angle or not. It bases the holdover on ranged distance and has a series of preset drop tables that you select during setup to match your rifle and load as closely as possible. No custom turret. No fixed holdover marks on the reticule.

If you want next level ballistic compensation and have about $4k to drop on an optics package, G7 optics will sell you a Nightforce scope with their own custom ballistic turret matched to your bullet and velocity from your rifle at your elevation and selected temperature. Combine that with their rangefinder and you get correction factors applied to the turret calibration for changes in elevation, temp and shot angle. Really high speed and no one else can match it, however they charge appropriately. The rangefinder alone is $1500.

[Ranger3]

Any quality scope with a good MOA or Mil Dot Reticle will work for ranging whether it's Second Focal Plane or First Focal Plane. Here are some informational websites. http://www.mil-dot.com/user-guide
http://www.shooterready.com/


I have 2 MOA scopes and have used the MOA to range, it works very well if you remember the formulas.

[helotaxi]

The problem with using a mil-dot or any kind of scaled reticule for rangefinding is that you must know the exact size of what you want to range for the thing to work. Error is magnified at range and the margin for error is reduced with range. Depending on how accurately you need to place the shot, and the consequences of being off a ranging reticule simply might now be an acceptable option.