I just bought 2 scopes with BDC reticles. I like the idea behind them, but what round are they based upon? For instance there are AR-223 scopes that are made for the ballistics of that round, But what about the average 3-9x40 or 4-12x40? I can zero at 100 yards, but a .270, .308, .243, .223 will all hit the 200, 300, 400 and 500 yard marks differently? Is there a base round that is used as a bench mark? Sorry if this is elementary, I am very new to precision shooting.

Just so you know my platforms are a .223 AR and a .308 bolt action.

This is why I hate BDC reticles.  They are based on one round, and even then they aren't all that great.  For precision shooting you are much better off with an optic with a MIL or MOA based reticles with matching turrets that you can dial.  

You could figure out where any round would impact on the BDC but it isn't very practical.  

This is absolutely true.

But, if you are stuck with BDC reticles, get Strelok+ ballistic software and consult its vast reticle library.  Enter your correct load data and zero.  If your reticle is listed it will show you an image of the reticle with each BDC point with yardage next to it.

A BDC is accurate for all of the following at the same time::

a) One chamber
b) One barrel length
c) One set of atmospheric conditions
d) Zero incline
e) One bullet (BC)
f) One bullet (weight)

Which is great if you happen to be using that gun, with that ammo, in those atmospherics.

Otherwise, not so much.

In practice, inside 400 yards it does not mater a whole lot.

Hopefully its a nikon. If so you can use the "nikon spot on" site or app. It is AWESOME. It has just about every commercially made round, you can even enter in custom load data. Check it out even if you have something other than a nikon bdc, it is very cool, and free!

Thanks for that info. I bought Vortex Diamondbacks.

Yeah thats kinda what i was thinking

this is why MIL/MIL hash is the way to go.  Standardized scale and all you need is plug-in values for a ballistics program for whatever projectlie at whatever your real velocity is.

As a side note, Nikon has a online calculator called Spot On that will calculate ranges for their BDCs with your round. Check with the manufacturer to see if they have something similar.

You can use a nice app called Strelok to get a very close indication of what your BDC is good for.   Want to make it even better? get a chronograph. It will give you the real speed of a cartridge out of your rifle.  I have a M-223 on a rifle and the turrets suck for my handloads.  I have another rifle with a BDC model on it and took it out last weekend and put 3 rounds in a 1.5" group using that dead space between the circles. The app ranged it perfectly or at least I hit a 4" plate three times.

Spot on gave me the same results.

Youll be fine with the BDC reticle on the dimaondback, dont consider it a BDC. Consider it a moa reticle in large broken increments.


This is your reticle, use the subtensions as you would use a mildot or any other graduated reticle, its no different. Disregard any BS about being a BDC, use it as a graduated reticle and learn to use what you got.

I'm jumping in here a bit late.  How does NightForce get their 600 LV BDC and FC-3G to work.  I've seen their ballistic calculator for various rounds and conditions.  The reticle is based on a 200 yard zero but the calculator will give a best site-in distance for X-brand and X-bullet.  NF will red flag 500 and 600 yard sometimes for being out of their specs.

I like the BDC concept.  JP Enterprises offers a JP ACOG with a BDC.  I'm interested in the NF NXS 2.5-10x42 LV600;  the see-thru MIL-DOT feature in the NXS is appealing too.

I guess I need some input.  My gun is a 16" Noveske Recce style for shooting competition, off bench and varmints with a NF 1-4 FC2.  The farthest I've tapped a plate is 440 yards.  It's very rare for me to shoot that far, but I'd like to have a scope ready if the need arises.  I'd like magnification 2.5-10 or 3.5-10?

Thoughts?

BDC reticles are good for when you want a simple reticle, and don't need large amounts of precision. They are very common in 3gun where we tend to shoot fairly large steel targets were any hit on steel is good. BDC's are usually built around .223 and .308 for this reason, as they are the most common calibers in 3 gun by far. It's pretty unusual to see anything but .223 and .308 in 3gun.

I am now using more of a "precision" optic for 3gun. I have a 2.5-10x32 FFP Vortex Viper PST MOA scope. Many of my 3gun friends think it's to busy of a reticle for 3gun.

When I used a BDC optic for 3gun, even using .223 it asn't exactly right, but it was fairly close. My 200 hold was actually 240, 300 was 335, 400 was 440, and 500 was 550. I used the Sterlok Pro app to get me on paper, and then went to the range to confirm. As long as I entered in the proper info, which meant cronoing my round in my gun, the app was pretty darn close.

Hmmm, interesting that you holds were about 10% greater than the BDC suggested but for the 200 yard hold.  You know that a meter is 1.0936 yards, right?  For most purposes, including mental conversions for ranging, 1.1 yards is close enough.  And, that's 10% different.

So:
 
      200m = 218 ~ 220 yards
      300m = 328 ~ 330 yards
      400m = 437 ~ 440 yards
      500m = 546 ~ 550 yards
      etc., ect., etc.

Perhaps your BDC is calibrated in meters?

LF

With all the smart gear today here's an idea:

Why not put a chip into a holographic scope which projects an image onto the glass (please pardon what may be my poor understanding of holo scopes) onto which you can load different ballistics for any rifle, barrel, caliber load and even atmospherics and the scope automatically corrects the BDC.  With such sophistication one could even load custom BDCs any time you liked which were simple or complex as all get out.  Importantly, you get to choose the level of complexity rather than having a manufacturer impose that decision upon you.

If you had several favorite rifles and several favorite loads (one for short-range, one for long-range precision shooting, one for barriers, one for a big loud bang at the range to impress people) load several ballistic charts and several custom BDCs and just select the one you want to use with a light pen or some other pointing device.  Then you could select the one you happen to load in whatever rifle you choose to use at any one time and still have a custom BDC.

Surely with all the wiz kids out there this would be an easy thing to build.

Taking it one step further, you could build in holographic training vids which appear right in the scope for training newbies on how to use the scope, how id targets, how to get a coffee and doughnut from the local Viet shop, etc.

Just kidding about the vids.

LF

Ahhh the unending laziness of those that are unwilling to learn about ballistics even just a little bit.

BDC's suck. That's a fact. They're wrong out of the box 99% of the time. You want to know how to use them, DON'T.

As a small boy had the pleasure to know my Great Grandfather.  He had come over from German just after the end of WWI and raised a very large family as a farmer in Ohio.  He too rather endlessly bemoaned the laziness of his progeny and of their progeny.  He plowed his fields with a draft house and he felt the old ways were better and that they produced a better person due to the ardor and hardship they produced.  So, from this perspective I view your response.

OK.  Granted that BDCs are so inaccurate relative to good scope work that they are an embarrassment to the manufacturers and they invite the sort of justified criticism you have made.  I completely agree.  I have the money to buy one.  I've not done so.  And, I've not done so for exactly the same reasons you cite.

But let's imagine that they could be made accurate for any rifle, load and atmospheric conditions and that could be done easily by using what I'll call a SmartScope (as I've briefly described above).  If you'll accept that fantasy (no such programmable scope exists, yet) then wouldn't milling and milradian-ing and range estimation and turret adjusting go by the wayside?  Wouldn't that revolutionize both civilian and military shooting?

There's this company in Texas (can't recall the name) that has a computerized rifle system that can lock onto a moving target (generally speaking, feral hogs, the bane of Texas farmers) and track them and alert the shooter when to fire.  As I understand it the owner of the company was once an Apache Helicopter pilot and thought the same technology he used to blow up Hajis could be used for hogs and, well, other warm blooded "prey".

Why not integrate such technology in infantry (militia) weapons?

I think it's a cool idea.  And, it would be infinitely faster and infinitely more reliable than old fashioned  range-finding, milling and firing...as long as the batteries held out.

Don't you agree?

LF

I was always impressed with how quickly Army Snipers were able to make hits on target at various ranges (to include past 1000m) with the Horus reticle. Without making adjustments to their turrets too. Just know your round.

Yep, I'd love to have one but for the expense and for my reluctance to use an AR15 for such a fine piece of glass.  I think a more appropriate rifle might be a 308.

LF

I run a Vortex with the BDC for p-dogging. Lil sob's are everywhere, 100, 200....500 yds.

I always use 55 gr v-max. I zero @ 100 yds, and learn the subtensions thru practice.

For my use a BDC is the best solution I've found for multiple ranges with fairly fast follow-ups.

Some of the best competitive shooters in the world would disagree with you.  Jerry Miculek is lazy?

BDC reticles work very well in action oriented sports where a hit somewhere on an 8" plate at 400 yards is acceptable. It may not be as precise as dialing or a mil scope, but 3gun competitors are far from lazy with their rifle work just because they use a bdc.

A little late into this conversation, but most BDC reticles are a generic solution to a unique question.  The hash marks are based on a specific weight bullet of a specific design and caliber, travelling a specific velocity out of the barrel.

Some manufacturers such as Leupold will make custom turrets or hash marks based on a pet load you submit, however that can be pricey, and good for that one specific load.

The other alternative is contact the optics manufacturer, discover what load their hashes are based on, then plot out your load's trajectory compared to theirs, and make note of where your projectile falls according to their hash marks.

I feel your pain dude, BDC reticles are nice for a certain type of round... but anyone can develop a hold chart for a round on an MOA or mil reticle.

This is a historical comment.


Their novelty turrets are so bad they had to make ballistic software for their reticle.

You can build it with any cartridge/load.  You can get on paper using apps like iStrelock and get precise distances for the hash marks by shooting.

BDC reticles are not married to any specific load.  

The marked turrets that some makers produce are married to the load.

Use the Vortex LRBC, input your load data, go down the menu to reticle (in orange under print options), find your scope, and presto there are your numbers. Its not perfect but its something.

iStrelock can do it with any reticle loaded into their database and they have hundreds.  You just have to know your true MV and the real BC of your bullet (some makers fudge a bit).  Nothing will replace practice shooting at long ranges for come ups.  That is a fact.

I recently replaced my Eotech 512 with a Vortex Strike Eagle 1X6 with BDC reticle.

The Eotech can only be zeroed at one range.   Outside of that range, you're guessing the drop.

The reticle of the Vortex Strike Eagle is documented to show the drop (in MOA) for the hash marks for 200 - 600 yards.    I played with JBM ballistics to find out what common bullet and muzzle velocity would result in a drop matching the reticle hash marks.    Turns out, Federal American Eagle,  M193, out of a 16 inch barrel results in a good match, out to 400 yards.   Past that, I won't be using a .223 anyway.

It works for me.

They're easy to calibrate.
Grab the subtentions from the reticle docs.

You need to know the velocity and bullet you are using.
Plug it into JBM ballistics with a 5 or 10 yard increment an a 100 yard zero.
Sight in at 100 yards.

The drop table generated by JBM will tell you what ranges the other hash marks correspond to.

For instance

Attached File

There is also an android app for this very same thing and it works quite well.

BDC, Mill Dot, & Hash mark Reticles are only as good as the Data shot from known ranges and Reviewed! Find the value of your reticle at each power setting then shoot data at known ranges then Check against your soft ware data. Most people will never shoot their scope past a 100 or 200 yards then wonder why they make a bad hit. But if you have good data then your soft ware will work better or your range cards will be more precise. Now the BDC type reticles become useless past a certain range with different calibers. So your going to limit yourself which for most shooters is a good thing. Now if the BDC reticles were FFP they would actually be better because that would cut out magnification error. Even Factory bullet BC's are very seldom correct and that is what the Ballistic soft ware uses to calculate. Which is why it's imperative to shoot data no matter what system you choose to use even turrets. Okay Rant Over! Have fun shooting your data and post your results!