This is a discussion on BDC reticles within the Defensive Rifles & Shotgun Discussion forums, part of the Related Topics category; Throughout the world of optics there are many scopes that integrate a BDC into the reticle markings. Initially these were offered for different calibers, but ...
Post By OldChap
Post By LimaCharlie
Post By Chuck808
December 12th, 2019 10:40 AM
Throughout the world of optics there are many scopes that integrate a BDC into the reticle markings. Initially these were offered for different calibers, but very little was done in regards to different weight bullets. Now I am seeing that some are offering multiple reticles for the same caliber (right now I am looking at a review of the Trijicon 1-6x24 mm VCOG which offers different reticles for both 55 and 77gr bullets in 223 Rem).
I am curious, how much difference is there between the different weight bullets in terms of trajectory, just based on the weight of the bullet itself. From a purely technical standpoint you would need to take both bullet weight AND velocity into account in order “properly” calibrate something like this. But, from a realistic standpoint, is there really that much difference in the BDC calibration between two scopes that are calibrated for different weight bullets in the same caliber or is it just another marketing tool? After all, when discussing zero for the AR I have heard people discussing different distances for different calibers and, in some cases, from subsonic vs supersonic, but nobody ever talks about the difference between the 55gr M193 and the 62gr M855 bullets.
Anybody have any experience with the BDC reticles that are “calibrated” for different weight bullets in the same caliber?
Not looking to make any decisions – just curious.
December 12th, 2019 10:49 AM
I've never used BDC's with calibration for different bullet weights in a caliber. I suppose a lot depends on the particular use for the gun. My AR's are tasked for home defense, so I really don't need stuff like that.
I recommend the great little program "Strelok Pro" which can be installed on an IOS or Android device. It has a function called MPBR (Mean Point Blank Range) which is much more useful for me because I can determine where to zero and how far out I can go without any holdover or under. As long as I'm within a few inches of center of mass, I just ignore that - no matter what load I run.
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December 12th, 2019 12:11 PM
I use the Strelok Pro app on my iPhone. If you want to get a lot closer, get a Kestrel 5700 meter.
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December 12th, 2019 12:11 PM
I feel like if you’re worried about absolute precision, where you are doing everything you can to make the first hit at extended range, you should probably just have a Mil-dot reticle and good dope, then dial in a firing solution.
If you’re looking to just get lead on target quickly, I’d go with an ACSS reticle. It isn’t different per bullet weight, but should get you pretty close regardless of what you’re shopping.
December 12th, 2019 04:34 PM
I've got BDC's on a couple rifles, and Mil Dots on a couple others.
Depending on your distance & targets size, BDCs are adequate. I use on on my 3gun rig for 0-400 yards on steel without an issue. On my hunting rifle I've used it out to 500yds with a small enough error to remain well within the kill zone of a deer. For both of these endeavors, there might not be enough time to either "click in" or count dots after reading a dope chart. The BDC IMHO is less precise, but faster.
Take limacharlie's advice and get a ballistic software program like Strelok. I use it in conjunction with my Kestrel to obtain data for my precision rigs, but it also will tell you the actual impact distance for your BDC reticle points based on your load and weather conditions.
For instance, my .270 has a 24" barrel and my normal hunting load is a 130 Nosler AB bullet at 3174 FPS at 37 degrees. My normal BDC impacts are off from the static dots:
300 dot really equals 334 yards
400 is really 447
500 is really 556
Because I also have Leupold CDS dials, I tape a dope chart to the side of my rifle with my dope and the actual BDC values.
The error is still well within the 8" kill zone of your average deer, so far "rapid engagements" the BDCs work, I just use the top of the dot as my aiming point.
IF you want true precision you're going to have to go with a MIL Dot (or better yet an MOA reticle, cause it's a little finer) and turrets with the same calibration. It's just way more accurate due to the increased number of aim points.
December 12th, 2019 05:28 PM
If you are using Strelok Pro, which is great, you can make a bdc reticle behave like a mildot/MOA reticle assuming they have your reticle in their database. Rather than aiming at x mildots down, you just look at the phone screen to see where on the reticle to hold for whatever data you have entered, including bullet weight, speed, drag, humidity, altitude, barometric pressure, etc. All those things work against a simple bdc reticle, but the Strelok nonetheless will show exactly where to hold, which happens to be the same place you would hold on a mildot or MOA reticle. I use ACSS reticles in most of my scopes. I feel I get the speed of a bdc and the potential precision of a mildot, but only when using Strelok (vs a dope card or similar which won't get you there with a bdc unless you know the mils for each hash mark on the bdc and then approximate where you mil holdover should be).
On some of the ACSS reticles, they have mildots included as well, although it is somewhat cluttered. You can also figure out the mildot for each hash on the bdc potentially. For instance, the last hash on my 6.5 Creedmoor 3-18 ACSS reticle is 8.4 mils (supposedly for 1000 yds as I recall). So to shoot beyond 1000, I'd have to dial the turrets to add to that 8.4 if using the lowest hash mark. I'd say the big downside for this particular scope is that it was developed around using Hornady 140gr ELD match bullets, which happen to be some of the most expensive bullets. While that may be satisfactory for big budget outfits, it sort of ruins the bdc for me because I use cheaper S&B ammo (52$/rd), which is half the price (and significantly worse ballistic coefficient)...although I just bought some Hornady Black (BTHP) ammo for 75˘/rd this week which has a better drag coefficient, so hopefully closer to the ELD bullet. The ELD is the best long range commercial bullet, so the scope is designed to make use of the long range capabilities of the 6.5 Creedmoor round.