BDC and other calibrated scopes

[crankycalico]

These are popular as ****, and well made as much as cheap burritos.

Problem I see is that they all seem to have 3 things in common:

specific bullet weight used
specific bullet velocity
specific barrel length

So yes, a BDC scope that's "garunteed" to 800 yards would be nice, but what does a fellow do when his rifle wont shoot that particular bullet weight, or shoot it accurately as that specified velocity?

[Petrol & Powder]

They operate by means of a cam and you are correct that they are dependent on factors such as bullet weight and velocity to be accurate with those pre-determined values. You could compensate for differences once you know how a particular round performs in a particular rifle but frankly I would stick with simpler solutions such as target turrets and Mil Dots.

[Moonie]

In the case of the Nikon BDC scopes there is software on their website and even a smart phone app that you can put your external ballistics information into including bullet weight and velocity and it will tell you where the circles line up with in range.

For the calibrated turrets there are places you can order custom turrets for your loads.

[rdwarrior]

Vortex has a software program where you select your scope, input information - bullet weight, BC, and muzzle velocity. It will print out a range sheet showing the range for each BDC crosshair at whatever magnification you have selected. I print out 3 different magnification sheets - minimum and maximum magnification and one right in the middle, i.e on a 3x9 scope, I print 3x, 9x, and 6x. With my 30-06 - using these printouts, I was able to put the first round on steel at 600 yards - no guess work.

[crankycalico]

I almost bought one of those Nikons when they were on a sale, but all the literature was stating 1 bullet weight and 1 velocity that my 18" barrel cant do, and a bullet weight it doesn't care for.

Now the ones with custom turrets seem nice, but they aren't cheap.

[cwheel]

I own a Shepherd scope (P1A) and it's mounted on a Remington KS 300 win mag. The scope is very good and tracks well if you do your part. I reload 165 gr loads 3275 fps measured with a chronograph. If I do my part reloading for the drop circles in the scope, it's very fast and dependable. I check the zero and make minor changes with each new lot of reloads. ( load for that one in 100 round lots, lasts for years just getting used for hunting, not a range gun) Not a cheap scope to be sure, but it works well. The draw back on this scope is that your bullet tejectory must match the drop circles in the scope. Fast to shoot and aquire a target
Chris

[redriverhunter]

I have not used them as advertised. I shoot my gun at various know distances with a zero lets say a hundred. then I use the bdc as reference points. I think my daughters 7mm 08 zero at hundred and at 320 yards it was either the bottom of the 1st circle or top of the 2nd circle. for me its a good scope with different reference points.

[dk17hmr]

I have never been happy with the few I have owned and even less interested after I bought an Applied Ballistics kestrel and learned how to use it.

The BDC systems aren't for me. The alltuide I'm shooting and hunting at can vary by 6000 feet, which plays havoc with predetermined ballistics. The idea is there and probably works really well for the type of guy that is shooting inside of 200 yards but sometimes takes a longer shot but doesn't want to spend the time and money to learn different methods that are more precise.