Leupold BDC?

Question

I feel kind of stupid asking this, but could someone please explain to me exactly how the leupold BDC with mil-dot reticle works? thanks.

Answer 1

Well, you are supposed to sight in the crosshairs to 100 yards. The rings under it are set to where the bullet would hit at certain yardages, but I am not sure what yardage eac ring is supposed to denote. The idea to it is that you no longer have to use the hold-over/under method to aim for a yardage further or nearer than you are sighted in for. The only problem with that is not all bullets fall the same amount at each increment, so the farther out you shoot the less reliable the sighting ring will be.

Answer 2

The Leupold Answer Guide

M3 BDC dial instructions

The M3 Long Range and Mark 4 scopes use a special bullet drop compensating (BDC) elevation dial. Each dial is calibrated for a specific load. On the top of the dial you'll find the caliber and bullet weight. For best results, we recommend that you use the correct type of ammunition for your caliber. On the side of the dial you'll find the BDC settings that correspond to the target range in 100 yard or meter increments. At the highest range setting you'll find the designation for calibration in yards or meters. On the bottom of the dial you'll see a small steel ball that acts as a stop. This ball prevents the dial from being rotated more than one full turn. It also services as a 100 yard or meter stop. When you lower the sight setting to the ball-stop you'll be at your 100 yard or meter setting. If you have a Mark 4 M3, your scope's internal elevation adjustment range is 72 minutes-of-angle. If you have a Long Range M3, your elevation adjustment range is 65 minutes-of-angle. Because of the ball-stop, your scope's internal adjustment range is greater than the range of travel in the dial. If your dial is calibrated in meters, we recommend that you zero the rifle on a meter range. Scopes that are calibrated in yards should be zeroed on a yard range. Using the correct dial and ammunition, zero your rifle at 100 yards or meters. You may find that your elevation dial runs out of travel before you achieve your zero setting. If this happens, simply loosen the setscrews on the BDC dial and turn the dial back away from the ball-stop, then lock it down. By doing this you'll pick up some of that extra adjustment range in the scope's elevation system. M3 BDC dial instructions: Once you have achieved a precise zero, loosen the setscrews and turn the elevation dial to "1", then lock it down. Your scope is now ready for use at longer ranges. If you determine the range to target to be 400 yards or meters, simply turn the elevation dial to "4" and aim on the target. No holdover is necessary. The BDC dial setting has compensated for the trajectory of your ammunition. When you return the dial to "1" your rifle will be zeroed at 100. The ballistic data that were used to calibrate your BDC dial were calculated for sea level at 59 degrees F. Deviation from these factors will change the path of the bullet. For this reason your BDC dial may not print at point of aim at all ranges. Generally speaking, increases in temperature will cause your bullet to strike higher.

The Leupold Answer Guide

BDC Inquiry

We can make a BDC (Bullet Drop Compensating) Dial for most Leupold scopes (excluding Rifleman and LPS). If the scope has the standard low profile adjustments a "Target" or "M1" Tactical adjustment must be installed. Once you have the correct adjustment style then we can laser engrave a custom BDC dial. To engrave a BDC we will need to know what cartridge you are shooting, the bullet type and weight, the B.C. of that bullet, the muzzle velocity, and an average temperature and altitude you will do most of your shooting. You may download and complete an order form at http://www.leupold.com/resources/custom_... or you may simply write this information on a sheet of paper with your request and send it here to the Custom shop. Pricing can also be downloaded at the same page and I will include it below. Service currently requires approximately seven to ten working days, not including shipping time. When shipping product for warranty or service, please include a note of instruction, return address, phone number and e-mail address. If you are having a chargeable service performed (reticle change, target adjustment installation, replacement of damaged components, etc.), please include payment with the scope to avoid delays in returning the product. Please record the model and serial number of your product and ship the optic only. Remove any mounts, rings, sunshades or lens covers. It is recommended that you purchase insurance and retain a tracking number to document the arrival of your product. If you need any further assistance please call our technical service department at [phone] or [phone]. Install one Target Adj 64.99 Install two Target Adj 104.99 Install one M1 99.99 Install two M1 129.99 Laser Engrave Target BDC 89.99 Laser engrave M1 BDC 99.99 Return shipping and handling 15.00 For shipment by UPS or FedEx: Leupold Product Services 14400 NW Greenbrier Parkway Beaverton, OR 97006 For shipment by mail: Leupold Product Services PO Box 688 Beaverton, OR 97075  

The Leupold Answer Guide

BDC Inquiry

Yes we can do a BDC dial for your scope. If the scope has the standard low profile adjustments a "Target" or "M1" Tactical adjustment must be installed. Once you have the correct adjustment style then we can laser engrave a custom BDC dial. To engrave a BDC we will need to know what cartridge you are shooting, the bullet type and weight, the B.C. of that bullet, the muzzle velocity, and an average temperature and altitude you will do most of your shooting. You may download and complete an order form at http://www.leupold.com/resources/custom_... or you may simply write this information on a sheet of paper with your request and send it here to the Custom shop. Pricing can also be downloaded at the same page and I will include it below. Service currently requires approximately seven to ten working days, not including shipping time. When shipping product for warranty or service, please include a note of instruction, return address, phone number and e-mail address. If you are having a chargeable service performed (reticle change, target adjustment installation, replacement of damaged components, etc.), please include payment with the scope to avoid delays in returning the product. Please record the model and serial number of your product and ship the optic only. Remove any mounts, rings, sunshades or lens covers. It is recommended that you purchase insurance and retain a tracking number to document the arrival of your product. If you need any further assistance please call our technical service department at [phone] or [phone]. Install one Target Adj 64.99 Install two Target Adj 99.99 Install one M1 99.99 Install two M1 129.99 Laser Engrave Target BDC 89.99 Laser engrave M1 BDC 99.99 Return shipping and handling 15.00 For shipment by UPS or FedEx: Leupold Product Services 14400 NW Greenbrier Parkway Beaverton, OR 97006 For shipment by mail: Leupold Product Services PO Box 688 Beaverton, OR 97075