TDS & B&C reticle drop values?

[drpbroun5]

As a new (ignorant) long ranger I'm trying to figure out how to apply the strata marks on the Leupold B&C reticle as well as the TDS in the Kahles and Swarovski scopes to my ballistics in several rifles. I like to zero for a maximum point blank range for the critter I'm hunting, elk and deer mostly. I shoot fast, high BC bullets. I use my Infinity program to get me in the correct ballistic ballpark. After field confirmation on my bullet's actual flight, how do I figure what each strata mark represents in actual bullet strike for any given enviromental condition, without fire testing by trial and error? I don't want to burn-up my barrel or any more $ than I have to. I talked to the tech reps at both companies and they don't have a clue as to what I'm asking. I hope you guys do understand what I'm getting at. (Great grammer!) I would appreciate any suggestions and help. Thanks.
Paul

 

[Michael Eichele]

You let your fingers do the testing.

This is a program that enables you to enter various BC's, velocities and air density, then based on your ballistics, shows you how to utilize your scope. You can compare differant reticles to see which ones work best for your loads.

 

[goodgrouper]

Forget the TDS and the B&amp;C reticles if you plan to shoot past 600 yards. Trust me, they will let you down sooner or later. I guarantee you that they can't adapt to all the variables in exterior ballistics in hunting situations. Many guys have learned this in my shooting seminars the hard way. You throw angles, new elevations, new temps, or bad mirage at them so they can't use the magnification they need to to match the impact line and <font color="red"> they are screwed! </font>

The only way to do it exactly (and in this sport, we must be exact as we can) is to figure out how much the value of your turrets move and DIAL your scope up based off of real time ballistic coefficient testing and inputing correct data into a ballistic program so it produces a chart customized to your scope and trajectory. This of course requires many gadgets and gizmos like computers, chronographs, inclinometers, levels, thermometers, wind gauges, altimeters, and so on.

If only it were as easy as these companies make it seem. Just buy a scope, mount it up, go test the lines a time or two, and then GO HUNTING!? Marketing and hype make money, not sense.

Nope. Good things are never that easy. Precision does not come from a reticle alone. There are way more things that go into it.

 

[Michael Eichele]

[ QUOTE ]
if you plan to shoot past 600 yards.

[/ QUOTE ]

That is the key right there. Often times though, for 0-600 yards a reticle alone can be of great value. The reason 600 yards is so paramount is because you can change alot of variables and still hit a kill zone of a deer at 600 yards. After that, gravity and time just win out, thus the need for the gadgets and ballistic calculator in conjunction with turret adjustments from 600 yards on.

 

[wapiti13]

I agree. Most hunting is still done under 600 yds unless you are setting up for a true "longe range" shot. Then you need the extra equipment(rest, wind meter, small computer, etc.). Once you sight in for a MPBR, shoot to different ranges and you will be good out to 600 yds. Just be sure to go to max power for the scope, or your stadia is "off". Good luck.

 

[älg]

After some searching, i found this info on the TDS reticle lines, meaning the elevation they provide for holdover use:

1:1,91 moa
2:4,58 moa
3:7,16 moa
4:10,02 moa

So if your ballistic program tells you you need 4,58 moa of elevation, go to the second line /ubbthreads/images/graemlins/smile.gif

You can convert these to milliradians by dividing by 3,4.


Those are pretty strange numbers, I guess the idea behind the TDS is to give some kind of "valid for all calibers" holdover reticle based on the charts they provide with the scope.

Apart from that, there are other reticles better suited for holdover as the values are more straight forward.

Hope this helps.

 

[MagMan]

Swarovski has the TDS ballistic calculator. HERE

If you need a Swaro registration number email me and I'll get you one.

 

[Michael Eichele]

[ QUOTE ]
Just be sure to go to max power for the scope, or your stadia is "off". Good luck.


[/ QUOTE ]

The scopes that feature the TDS reticle have 2 differant triangles (points of referance) for differant hold over values. One setting works well with standard calibers and the other with magnum calibers.

The program allows you to select between them and see which one works best for your load. The values and how they relate to your drops are changed instantly upon changing between small and large.

 

[MachV]

Not precise but your only talking under 600yards and should get you there.
Just get as large a target as you can find marked off in inches or just take a yardstick and put it @ 100yards.Look at the target through the scope set at whatever magnification you are going to hunt at 100 yards.Then just read off the inches and if you want you can convert to MOA but your going to be real close anyway.
You can also adjust the magnification to suit your round a little better,just put a calibration mark on the scope and always dial all the way up and then down to your calibration mark.
It goes without saying that this is not exact but will get you on paper to 500yards with relative ease.Field adjustments will need to be made and likewise anytime conditions change you'll have to check for needed adjustments.

 

[drpbroun5]

Goodgrouper, do you have a sylabus, books, materials, lists, etc. that I could purchase from you so that I can figure out what I'm doing. What is the deal about your seminars also. Could you send me some info? I'm eager to learn. Thanks.
Paul

 

[älg]

[ QUOTE ]


[/ QUOTE ] [ QUOTE ]


[/ QUOTE ]

That´s why a FFP reticle makes sense to me /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/wink.gif

 

[drpbroun5]

alg,
Does the MOA value for each line on the reticle represent that much drop from the zero point? For instance if I were to zero my rifle for 375 yards, I would assume one MOA drop would be at 475. I would then figure that a 1.91 MOA drop would correspond to hitting dead on at approx 565 yards. Is all this correct? How do I figure out what each MOA value there is for the inch drop shown on my Infinity ballistic print out for any given load? Thanks for the help.
Paul

 

[drpbroun5]

What is an FFP reticle? As a new member in this forum, I'm not familiar with all the letter abreviations that you guys use. Is there a list of these abrevs?

 

[älg]

Paul:
FFP is a front focal plane reticle; its size increases or decreases as you increase or decrease the power setting of your scope. If I am not mistaken Goodgrouper was referring to people encountering problems when, being used to use the reticle for holdover at a certain magnification ( as is necessary in second plane reticles, whose size does not change), they could not use the magnification needed for the reticle. A FFP reticle will change its size but the holdover values for the different stadia remain constant.

As for yor question on the TDS reticle, if you aim at your target using any of the lines below the main crosshair you are aplying an elevation of xx MOA . I am not familiar with the INfinity program but for shooting LR you want a ballistics chart that tells you, among other things, how much elevation you´ll need to hit your target at xx distance, i.e.4 MOA at xx yds. SO to provide this elevation you can either use your scope elevation knob or use the reticle and hold for the 4 MOA you need. The problem with the TDS is that it does not use straight numbers, i.e. 2, 4, 6..moa.

In a FFP reticle, the stadia work well at any magnification; in a second focal plane, they only work well at one specific magnification.