Rifle Scopes BDC cam vs BDC Reticle vs Come Ups

[libertyman777]

One option I'm trying to decide on is a BDC reticle, vs BDC cam vs come ups. Which do you guys prefer and why?

Most of the long range shooting I will do will be training related and the occasional match (Hardrock, etc.) I also have a farm that we're planting trees on. Firebreaks are mandated and I might have 800 yard opportunities, certainly 600.

Hunting shots here in my part of the country are usually less than 100 yards but there will be some green fields along the firebreak that might provide longer than normal shots.

I like the idea of something like the Zeiss Z-800 or 1000 reticle. It's located in the 2nd plane and would allow some tuning with respect to a particular load.

BDC turrets are cool but are load matched. I guess this is okay as long as one sticks with the same load.

Come ups seem the most flexible but maybe not as fast, especially on a followup shot.

The rifle will be a Steyr SSG 69.

What say y'all.

 

[Rob01]

Re: BDC cam vs BDC Reticle vs Come Ups

I am not a fan of BDCs no matter where they are. Only set up for one load in one condition. I would rather have my data and dial it on or hold the mils if it needed to be done faster.

 

[Lindy]

Re: BDC cam vs BDC Reticle vs Come Ups

I agree with what Rob said.

We just finished a class of guys with BDC scope turrets, and their BDCs were substantially off.

Fortunately, their turrets were marked with both the BDC and marks in either minutes or mils, so they were able to record their dope accurately, along with the conditions at the time.

The problem with any BDC is that you get dependent on it, and don't get familiar with what your dope actually is. Instead of recording that your 1000 yard dope is 27.5 MOA, you wind up with 9+.75 or some such.

Get a universal graduated reticle and turrets to match. Get familiar with your data in MOA, mils, or whatever. You'll be much better off.

And you can transfer that scope to any rifle.

 

[BobinNC]

Re: BDC cam vs BDC Reticle vs Come Ups

The so called BDC CAM, is a flawed concept. It does not CAM anything. It is just a dial that is marked for a specific cartridge. The gears or CAMS are the same as any other dial, that moves in increments of 1/4", 1/2" or 1". There is no "special" drop compensation embedded in the CAM. If you have a dial set for particular round, you can change dials to "fit" another round. No magic, and the scope is really not compensating for anything, only the dial.

If you have a Leupold M3 dial set for a 308 175 gr SMK, you can call Leupold or Kenton, provide them your data, and have a new dial made for say a 155 gr Palma. Your CAM stays the same, only the dial has changed.

A BDC reticle is another matter, and cannot be easily changed.

 

[sscoyote]

Re: BDC cam vs BDC Reticle vs Come Ups

I probably have and use maybe 20 different BDC reticles for long-range shooting and hunting. Buddy of mine just killed a coyote at 535 yesterday using a multi-stadia reticle, and i killed 1 several weeks ago at 557. They work fine once u figure out how to apply them as accurately as possible.

 

[steve123]

Re: BDC cam vs BDC Reticle vs Come Ups

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: libertyman777</div><div class="ubbcode-body">One option I'm trying to decide on is a BDC reticle, vs BDC cam vs come ups. Which do you guys prefer and why?

Most of the long range shooting I will do will be training related and the occasional match (Hardrock, etc.) I also have a farm that we're planting trees on. Firebreaks are mandated and I might have 800 yard opportunities, certainly 600.

Hunting shots here in my part of the country are usually less than 100 yards but there will be some green fields along the firebreak that might provide longer than normal shots.

I like the idea of something like the Zeiss Z-800 or 1000 reticle. It's located in the 2nd plane and would allow some tuning with respect to a particular load.

BDC turrets are cool but are load matched. I guess this is okay as long as one sticks with the same load.

Come ups seem the most flexible but maybe not as fast, especially on a followup shot.

The rifle will be a Steyr SSG 69.

What say y'all.
</div></div>

I do both!

I have a NF 2.5-10 with their low velocity reticle on my AR.

I've got the whole system tuned with(ammo velocity,BC and sight in range)to my local so I can use the holdovers in the reticle out to 600Y.I was just out this morning double checking to make sure it was OK.It was perfect!!!

I also have it set up at the same time for a zero at 100Y with the turrets,so I can use it at any local with the ballistic program by dialing and using the main crosshair.

I'm very pleased how it worked out!

Steve

 

[IsleofGough]

Re: BDC cam vs BDC Reticle vs Come Ups

Flagstaff (and most of Afghanistan) are places bdc dials would not be accurate due to land elevation. I've had bdc dials and it is a as much trouble memorizing how far they are off at various 100 meters as just memorizing the mil clicks for 100-1000M. And you can use non bdc scopes for other rounds.

The worst scope for this is the MST-100. You have to know how many moa adjustments for each 100 yards and then estimate adjustments for distances between each 100 yard (ie: is it better to go down or up in yards and then adjust for moa shift)

 

[Rafael]

Re: BDC cam vs BDC Reticle vs Come Ups

I agree with those who suggest niether a BDC reticle nor knob.
A Mil, MOA, or IPHY reticle and knob combination can do everything a BDC can do, and more. The fact that they are not dedicated to any trajectory or condidtion is another bonus.

 

[steve123]

Re: BDC cam vs BDC Reticle vs Come Ups

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: GoughIsland</div><div class="ubbcode-body">Flagstaff (and most of Afghanistan) are places bdc dials would not be accurate due to land elevation. I've had bdc dials and it is a as much trouble memorizing how far they are off at various 100 meters as just memorizing the mil clicks for 100-1000M. And you can use non bdc scopes for other rounds.

The worst scope for this is the MST-100. You have to know how many moa adjustments for each 100 yards and then estimate adjustments for distances between each 100 yard (ie: is it better to go down or up in yards and then adjust for moa shift) </div></div>

Normally that would be true with standard BDC reticles and/or BDC turrets but NF has high velocity,medium velocity and low velocity reticles.You pick the closest one to your gun.Even with no tuning I was only off 1/2 MOA at 600Y...only 3"...not much.This scope is dedicated to this gun so for me it's just what I want.

I'm not suggesting that my LV reticle will work at every altitude perfectly but with my scope,that has 1/4moa adjustments.I can just dial like normal and use the main crosshair for any scenario.

I just went to JBM and used the 308 data on the page just to see what the difference in drop was at 600Y from 5000ft alt to 6000ft alt and it was less than 1".So I'm sure I'd be GTG for at least 2000ft change in altitude since I don't think I can hold 2" consistently at that distance.

Steve

 

[Rafael]

Re: BDC cam vs BDC Reticle vs Come Ups

Each new BDC reticle is introduced with the intent that "this one will make it easy". They all do the same thing.

Many manufactureres have taken to producing different versions of BDC reticles for different trajectories. They do it because they know there is a market they can capture....it has little to do with how well they work. The fact that they come out with multiple versions to "better" suit mutliple trajectories is proof that they understand there is no one-size-fits-all solution to the problem. To continue with that train of thought....the variances do not fit into 3 categories of velocity.....unless we all switch to the same 3 choices of: bullets of the same BC and weight as the next guy.....and only shoot the weapon in similar conditions.

The best solution is to create a drop table based on conditions and trajectory, and apply that to a reticle.
This is easier if you start with a reticle with known graduations. Sure, you can use the graduations built-into a BDC reticle, but why remember arbitrary graduations when you have ready-built MIL/MOA/IPHY models already built; they can be used just as well on any rifle with any bullet at any speed in any condition. You can even swap a broken mil scope with a good mil scope and keep running without changing anything.

I can print one ballistic table for a praticular trajectory/condition and apply drop values to any Mil/MOA/IPHY reticle and accomplish the same thing as a BDC reticle.
How many here operate on the original "single" ballistic table they printed out when they first ran the calculations for that rifle? I know I carry multiple tables for changing conditions, and I may change that table if I discover a variance that is causing misses.

 

[Lindy]

Re: BDC cam vs BDC Reticle vs Come Ups

I carry three items for doing elevation calculations.

A Density Altitude firing table for my load produced by JBM Ballistics.

A table of Pressure Altitude as a function of station pressure, and a chart which allows me to correct pressure altitude for temperature which yields Density Altitude.

Those came from this article, written by a guy who hangs out on this board:

Manual Calculation of Density Altitude

With those, and my Casio Pathfinder wristwatch, I'm good anywhere even if my Kestrel takes a dump and cannot calculate the density altitude for me.

 

[Rafael]

Re: BDC cam vs BDC Reticle vs Come Ups

I never doubted you were prepared, Lindy. Well prepared.
How many different variations of DA to you account for if you have no idea what the conditions will be....out of curiosity?

I have followed you on the DA thing and I do appreciate the fact that you are only dealing with a single variable as opposed to multiples; the way I am doing it.

 

[Lindy]

Re: BDC cam vs BDC Reticle vs Come Ups

The JBM table can be printed using a small font, and carried in a pocket. The one I carry has data for ranges from 500 yards to 1000 yards, in DA steps of 1000 feet ranging from -4,000 feet to 15,000 feet.

The card I carry, which is double-sided and laminated, is 2.5" by 5". Fits in a shirt pocket. Very handy.

 

[alpha6164]

Re: BDC cam vs BDC Reticle vs Come Ups

My buddy just got a NF Low Velocity Reticle for his 20" Tikka T3 .308 and it works awesome. With 175gr SMK at 2610ft/sec and 200yard zero he is perfectly on at 200, 300, and 400yards. At 500yards he is 1/4MOA and at 600yards he is less than 1/2MOA off. That is pretty damn good.

He tried the Blackhills 180gr Accubonds and it is even a better match. At 600 yards he is 1/8MOA off and no where from 100-600 yards is he more than 0.2MOA off.

And to give you a 3rd load to see how well this reticle is designed he also tried south african 7.62 Nato 147gr at 2680ft/sec and believe it or not it was the BEST match to the reticle. Sighted in at 200 yards he is not where more than 1/8 MOA off from 100-600yards. That is pretty hard to beat without having to dial anything. And that is an example of three different bullet weights, BC and velocities and all are very good match for that reticle.

Of course he always has the option to actually dial it if he wants to. He is not gonna win any bench rest competition but i think for rapid deployment either in hunting or tactical situations when you are engaging targets in different distances, that reticle works really great.

 

[Lindy]

Re: BDC cam vs BDC Reticle vs Come Ups

BDC reticles work fine at ranges where your dope doesn't change substantially with atmospheric conditions, i.e., 500 yards or less.

But that means there's not much point in having a BDC at the distance where the dope doesn't change, and they don't work at ranges where it does.

Since this is the web site for serious tactical shooters, rather than varmint hunters, here's my advice for serious tactical shooters:

Memorize your dope out to 600 yards - it doesn't change much with conditions. If you want speed, you can shoot those distances from your 100 yard zero using reticle holdovers, and don't have to touch the scope.

Be prepared to accomodate changes in atmospheric conditions at longer ranges, especially if the altitude of your AO changes, whether you do that by carrying a ballistic computer or a Density Altitude dope card and a Kestrel.

Leave the BDCs, whether in a reticle or a scope cap, to the amateurs who shoot in places where no one is shooting back.

 

[alpha6164]

Re: BDC cam vs BDC Reticle vs Come Ups

^^^Here is my dope for my FNAR .308 with Federal 175 GM:

MOA
100 0
200 1.8
250 3.1
300 4.6
350 6.2
400 7.8
450 9.6
500 11.5
550 13.5
600 15.6

These are not numbers that are easy to remember, and i would really like to see someone under stress trying to remember that they need 9.6MOA at 450 yards. Even if you were able to recall quickly, you can either dial 9.5 or 9.75 MOA with a 1/4 MOA knob so at best i would still be 0.1-0.2MOA off anyways which is no better than the NF Low velocity reticle.

 

[IsleofGough]

Re: BDC cam vs BDC Reticle vs Come Ups

Most people memorize the 100 yard values: 18, 46, 78 etc. You can extrapolate pretty well between them. But they will vary according to load, elevation, temperature and barometric pressure, angle of shooting, etc. They will even vary slightly between one shooter and another.

I think Lindy summed up the issue: for short range, just memorize the numbers (it works as well as BDC). For precise accuracy or for long range, BDCs really aren't accurate and you will need software or more precise charts to carry with you.

 

[Lindy]

Re: BDC cam vs BDC Reticle vs Come Ups

You can't dial a tenth of an MOA, so there's no point in keeping numbers to that resolution.

For a .308 with most bullets you'll be fine using this:

200 - 2
300 - 5
400 - 8
500 - 12
600 - 16

But it's easier to do in mils.

 

[libertyman777]

Re: BDC cam vs BDC Reticle vs Come Ups

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body">You can't dial a tenth of an MOA, so there's no point in keeping numbers to that resolution.

For a .308 with most bullets you'll be fine using this:

200 - 2
300 - 5
400 - 8
500 - 12
600 - 16

But it's easier to do in mils.
</div></div>
So converting to mils would be:

200 - .6 mil
300 - 1.5 mils
400 = 2.3 mils
500 - 3.5 mils
600 - 4.6 mils

How discrete should the interim distances be? Should I consider 25 yard increments starting at 300 yards, 400?

Paul

 

[IsleofGough]

Re: BDC cam vs BDC Reticle vs Come Ups

It depends on your load and conditions. My standard in tenths of a mil is 6,14,23,34,46,60,76 for average conditions around here FGMM 168gr. 10 MPH sideways wind is 2,4,6,9,12, etc. MOA adjustments are a pain to memorize as you really should memorize the nearest 1/4 MOA for most scopes I've used.

 

[Lindy]

Re: BDC cam vs BDC Reticle vs Come Ups

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">How discrete should the interim distances be? Should I consider 25 yard increments starting at 300 yards, 400?</div></div>

My shooting is oriented toward the problem of quickly hitting human targets who urgently require shooting. I interpolate as necessary according to the size of the exposed target. Which is what you'll have to do with a BDC.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">My standard in tenths of a mil is...</div></div>

I find it much less confusing to think in mils with one decimal point. You will have much more familiarity with your dope by thinking in milliradian units and not dialing clicks. But my .308 dope out to 600 is about the same as yours.

 

[TOP PREDATOR]

Re: BDC cam vs BDC Reticle vs Come Ups

the bdc reticles and cams are using a particular ammo / equipment they are saying to use. if you have different ammo, barrel length, etc. it will not be the same as what they are saying it should be.

mil dots for ranging, and a data book telling you where to dial it is the king, and will be based on your setup. not a suggested pre programmed setup that you are not using.

IMHO the bdc reticles and cams are the "hail mary play" of shooting.

 

[sscoyote]

Re: BDC cam vs BDC Reticle vs Come Ups

I calculate mine in 50-yd. intervals to ~600 yds. as well. In fact 1 of my favorite ballistic reticles/optics is this 1--

here's a better pic of the reticle--

It's a 22 Long Rifle specific BDC reticle that i put on an AR-15 recald to the trajectory of the JLK 65 Low Drag at 3050 mv. This was a coyote killing machine out to ~500 or so. Here's how i apply the reticle interpolatively (always in tenths of each individual unit of subtension) to minimize confusion in the field (not for the above reticle)--

Any additional dope goes in a Butler Creek Blizzard objective cover (can be disassembled to attach the drop chart or reticle-rangefinding in it)--

As far as i can see this is the fastest and most flexible application of a ballistic reticle i could think of.

 

[sscoyote]

Re: BDC cam vs BDC Reticle vs Come Ups

I should clarify that this is the fastest system besides the system that's calibrated + tested specifically to a shooter's load and condition for 2nd FP reticles that are set up to match even hundred yd. intervals.

The fact is i competed at a "tactical"-style sniper/prairie dog match in which we needed to engage 10 PD steel silhouettes at ranges of 200-425 yds. 1 shot each. I could only run 1 relay with these guys and i finished about avg. (80%--woulda' been 90, but i couldn't even see 1 shorter range tgt. from my position) using this 3 MOA reticle in the same AR (this was off a ballistics programs calcs. only--no time for testing)--