BDC on reticle and using elevation knob

[ronas]

If a scope has an elevation knob and you use it to zero the rifle at say 100 yard then the center of the retical will be the point of impact at 100 yards, I think that right.

Now if you want to shoot at 300 yards would it be correct to say you could use the BDC in the retical or adjust the elevation using the knob and still aim using the center of the retical.

[BamBam-31]

To the best of my very limited knowledge, that is correct. The benefit of a BDC reticle is that you can get off that 300 yd. shot quickly w/o having to fiddle w/ the knobs.

[Pthfndr]

If a scope has an elevation knob and you use it to zero the rifle at say 100 yard then the center of the retical will be the point of impact at 100 yards, I think that right.

Now if you want to shoot at 300 yards would it be correct to say you could use the BDC in the retical or adjust the elevation using the knob and still aim using the center of the retical.

The short answer is - yes, you could just hold over using the BDC on the reticle.

But, if you have a scope that comes with a factory standard BDC etched in the reticle, it will be for a standard load. Such as Fed GMM .308 with the Sierra 175gr SMK, or mil spec .223, etc. And it would be for that load at a specific temp, altitude, atmospheric pressure and so on. If the load you are using is not exactly the same, your point of impact (POI) would be off some.

If your elevation knob has BDC marks on it you would adjust the elevation knob for the distance and then hold with the cross hairs centered on target. But the same rules for the load would apply.

If you have a load worked up for your rifle, and have shot it at known distances to confirm your come ups, you can give that information to the scope maker (such as US Optics) and they will etch the reticle and/or elevation knob to be calibrated for YOUR load.

BDCs are ok for hunting, large moa targets such as steel plates in 3 gun comp, or for military applications where the target is "minute of man", but are not so great for precision work. Especially at long range (600 yards +).

[ronas]

The short answer is - yes, you could just hold over using the BDC on the reticle.

But, if you have a scope that comes with a factory standard BDC etched in the reticle, it will be for a standard load. Such as Fed GMM .308 with the Sierra 175gr SMK, or mil spec .223, etc. And it would be for that load at a specific temp, altitude, atmospheric pressure and so on. If the load you are using is not exactly the same, your point of impact (POI) would be off some.

If your elevation knob has BDC marks on it you would adjust the elevation knob for the distance and then hold with the cross hairs centered on target. But the same rules for the load would apply.

If you have a load worked up for your rifle, and have shot it at known distances to confirm your come ups, you can give that information to the scope maker (such as US Optics) and they will etch the reticle and/or elevation knob to be calibrated for YOUR load.

BDCs are ok for hunting, large moa targets such as steel plates in 3 gun comp, or for military applications where the target is "minute of man", but are not so great for precision work. Especially at long range (600 yards +).

That's interesting. I kind of figured that the ballistic specs. for even different size, shape and weight of bullets used would need to be taken into consideration. So it seem that a scope without BDC on reticle or even BDC marked on the elevation knob would not be required. One would just need to have a notebook with the relevent information to keep track of what elevation should be set for a given bullet at a given distance. Hope that makes sense. I'm I close to correct in my thinking?

[Pthfndr]

That's interesting. I kind of figured that the ballistic specs. for even different size, shape and weight of bullets used would need to be taken into consideration. So it seem that a scope without BDC on reticle or even BDC marked on the elevation knob would not be required. One would just need to have a notebook with the relevent information to keep track of what elevation should be set for a given bullet at a given distance. Hope that makes sense. I'm I close to correct in my thinking?

Yes.

Here's a drop card for one of my rifles I shoot in competition. It's laminated so it doesn't get mangled.