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Long Range Drop Compensators
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I was watching this video over the weekend: Best of the West - Beyond Belief, Long Range Video Productions. In general I found it well made and interesting - not wanting to get into ethical issues about long range shooting and hunting.

One issue interested me. In the video, they were using long range drop compensators - i.e. scope adjustment devices - allowing them to click to a particular range. The video does not cover the equipment used in any great detail (reserved for a future, follow-up release), but they made a comment that sounded like the drop compensator was calibrated to match the trajectory of the rifle/caliber/load used. Is that possible?? If yes, who offers services like this??

I was under the impression, that most drop compensators (at least the ones that are reticle based - such as mil-dots, TDS etc) are all approximations, and you basically have to "match" your particular round/load to fit within several groups. E.g. depending on the external ballistics of your load, you would choose a particular compensation for 500 yds, say. But for another caliber/load, you'd have to choose a different compensation (reticle holding point). In the video, they are using a scope adjustment compensator, i.e. click based as opposed to reticle based. But, it would seem to me, that for a given scope, a particular number of clicks would also adjust your POI differently depending on the caliber/load/trajectory that you happen to use. So, how realistic is the impression I got from the video, that such a range compensation device can be "tailored" to your particular load??

Maybe there are other places on the Net, where I might find further information? I gather there are websites for tactical and long range shooting. Anybody know of good places to look??

Thanks a bunch in advance

- mike

P.S. It just occurred to me, that if you had the adjustment knobs custom made, you could have the graduation lines (i.e. the lines indicating adjustment for 100, 200, 300, 400, 500 etc yds) so that they matched a particular number of clicks on the scope. Then it might be possible to make a tailored compensation device for a particular caliber/load. Don't know if this might be the clue?? If yes, the question still remains: does anybody offer such custom made adjustment knobs??

Also, does a compensation between 4-500 yds always require the same number of clicks as a compensation between 6-700 yds, say?? I.e. could you make your graduation scale on the adjustment match a fixed number of clicks, or would each compensation interval have to be evaluated established through testing, and then the scale graduated accordingly??


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The rifle is a noble weapon... It entices its bearer into primeval forests, into mountains and deserts untenanted by man. - Horace Kephart
 
Posts: 6653 | Location: Switzerland | Registered: 11 March 2002Reply With Quote
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Aloha Mike,

Im sure theyre are more qualified people than me on this issue but I will say that you pretty much answered your own question really in that yes it is very realistic indeed I have the dvd as well. What you do is zero the rifle/load combo at a known distance then you shoot at varying known distances and record drop etc. that way you know how much clicks it takes to aim dead center in stead of holding over etc. so that way if you know the distance (rangefinder) you can dial your scope in so that you aim using the crosshairs as you normally do.

The one thing that did interest me was the fact that the amount of clicks were diff. then on a conventional scope turret which I believe the calibration you talk about comes into play. The above mentioned way I described is for use with a conventional system. Im waiting for the 3 part series becomes available to see the scope system they use. Hope that helped a little but im sure others will answer.

Aloha!!!

PS I mustve been writing when you edited but I believe that pretty much sums it up and I personally dont know of anyone who makes custom knobs etc. I think the compensation between diff. yardages would be diff in that a bullet drops more as it loses speed etc for example it may drop only 7" from 3-400 yds but 14" from 4-500yds so the compensation for the example would double as it gets further. JMHO not sure if its correct or not just a thought.


Hunting its not a Hobby its My Way of Life!!!
 
Posts: 449 | Location: Kaneohe,Hawaii | Registered: 20 September 2004Reply With Quote
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I have been useing mil-dots now burris muti plex for many years. I chose bullets and vel to match them. They are great for hiting out to their limits.

These with a laser range finder make first round hits easy.
 
Posts: 19379 | Location: wis | Registered: 21 April 2001Reply With Quote
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it's possible to get black scope knobs (bushnell for 1 makes them) then you can mark up your own ranges on them.
 
Posts: 13446 | Location: faribault mn | Registered: 16 November 2004Reply With Quote
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mho try this link. They make custom turrets for some scope modles http://www.kentonindustries.com/
 
Posts: 44 | Location: Southern Wisconsin | Registered: 14 April 2003Reply With Quote
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That Kenton Industries link looks pretty much like it. Has anybody tried one of these??

Just for laughs, I tried to calculate (note: calculate as oppose to verify) the scope adjustments needed @ 100 yds (pretty much gives the number of clicks) to give a zero range at various distances up to 1000 yds. The adjustmenst per 100 yds zero increase, vary from about 1.2" (going from 100 to 200 yds zero) to about 4.4" (900 -> 1000 yds zero). Here are the numbers:

Load: .300 Win Mag, 168 grs Barnes TSX, est @ 3200 fps @ muzzle.

Zero range (yds) Correction @100 yds (in)
100 -- 0
200 -- 1.18
300 -- 3.05
400 -- 5.24
500 -- 7.72
600 -- 10.52
700 -- 13.59
800 -- 17.04
900 -- 21.01
1000 -- 25.39

As it can be seen, and as we had probably guessed, the adjustment required to dial in an extra 100 yds zero, increases the further away your zero gets. I wonder if the Kenton compensator takes that into account??

Additionally, it is kind of rare that I find a scope where the advertized click adjustments actually match the adjustment you get in real life. Some of the Euro scopes come pretty close, but most other scopes give more actual adjustment per click than advertized. I don't know if you have come to the same conclusion?? This would be another variable involved in producing a customized drop compensator.

All in all, it is likely that UltraMag is right when he claims, that to produce a drop compensator, you must actually verify your own POI data, and then have the compensator built accordingly - something which Kenton apparently offers.

- mike


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The rifle is a noble weapon... It entices its bearer into primeval forests, into mountains and deserts untenanted by man. - Horace Kephart
 
Posts: 6653 | Location: Switzerland | Registered: 11 March 2002Reply With Quote
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I've been using the Burris ballistic plex reticle with good results for a couple of years now. For my 270 I sat down at the computer and printed up some tables for my rifle, chronographed load, BC of bullet etc. I also calculated how things should look at 100 yds. After a bit of tweeking I shot at targets out to 500 yds. to see how things actually lined up. Tweeked a bit more and now have a very quick and accurate way to line up for deer and antelope out to 400 yards.

I also have the same scope on my CZ 22LR for gopher hunting. Works wonderfully, I've even made a few 150 yd. shots, but mostly it's a matter of sight picture practice. For long range real world practice with my 270 I like to hunt marmots in July.

For big game you must have a good rangefinder. Even though I've hunted the same areas for years I still surprise myself by under-estimating or over-estimating yardage on occation. This is stunningly easy to do at over 200 yards much less 3 or 4. 50 or even 25 yards off at long range and you will miss or worse.

Range compensating reticles are great, but like any tool you must learn how to use it and work with it. Yep, it takes practice, again. There are no quick or easy solutions.
 
Posts: 763 | Location: Montana | Registered: 28 November 2004Reply With Quote
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Our "1894" suggested I take a peek over at LongRangeHunting.com. There is a whole "sub-culture" of long range riflery over there. Quite interesting. The information about bullet drop compensators was a little sparse, but it seems like the Kenton Industries option is the pick of the litter - not counting DIY bullet drop compensators. Interesting stuff.
- mike


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The rifle is a noble weapon... It entices its bearer into primeval forests, into mountains and deserts untenanted by man. - Horace Kephart
 
Posts: 6653 | Location: Switzerland | Registered: 11 March 2002Reply With Quote
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Leupolds custom shop will make you a custom engraved turret for anything but LPS scopes (I think) They will make it based on muzzle velocity and ballistic coeff. or you can send them your own measured drop values (the better way) I looked this up after seing the best of the west tv show. I do remember it being a little time consuming on the leupold website to figure it out though. I think it was all in their catalog under custom shop.
 
Posts: 153 | Location: Omaha, NE | Registered: 06 December 2004Reply With Quote
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I have been using a Bushnell 4x12x40 BDC for quite a few years. As I am useing a 308 there is a "dial just for that, that covers 1 or 2 bullet styles and it is quite accurate. This dial is calibrated from 75 out to 650 yds. Bushnell supplys, in with each scope, a blank dial that one tunes to their particular rifle and desired round.
All I do is range my target, dial in the appropriate distance on the dial and hold dead on, then squeeze off the shot! HOWEVER, distance is one thing and wind drift is something else again. I am supremely confident of my rifles ability out to 325 Meters(the longest range I have available to me) but I don't read wind worth a darn,so I don't hunt with this rig. derf


Quando Omni Flunkus Moritati
 
Posts: 3450 | Location: Aldergrove,BC,Canada | Registered: 22 February 2003Reply With Quote
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Cool stuff guys, the collective knowledge on this board always amazes me. What a great place to pick up information! The Leupold Custom Shop sounds like a very viable option in addition to the Kenton Industries.
- mike


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The rifle is a noble weapon... It entices its bearer into primeval forests, into mountains and deserts untenanted by man. - Horace Kephart
 
Posts: 6653 | Location: Switzerland | Registered: 11 March 2002Reply With Quote
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mho
Most of the guys at LRH rely on the DIY charts and target knobs, Some go so far as using palm pilots with ballistic programs. That way they can take into account things like altitude, barometric pressure, humidity, temp., dew point, and a whole host of other variables that can change the point of impact especially at longer ranges.
Chris
 
Posts: 44 | Location: Southern Wisconsin | Registered: 14 April 2003Reply With Quote
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Chris,

I find the subject of long range shooting fascinating, but probably only to the extent where it can be practiced in the field. I know Horus also relied on programs for their shooting systems to be run to perfection (very busy reticle plus programs hosted on hand held computers). I'm sure this allows an expansion of the envelope, but at least at this stage in the game, I find it a less interesting option, simply because it is impractical in the field. Who knows, perceptions have a way of changing once you emerge yourself into a subject...

I saw some of the DIY BDCs over on LRH. Nice jobs some of them, although some suffered a bit from lack of simplicity. That was what fascinated me so much by the BDCs used in the "Beyond Belief" video, their system was simple enough, that it could reasonably be expected to work in the field. It has been my experience in the past, that complicated systems often break down in the view of stress in hunting situations - sadly.

- mike


*********************
The rifle is a noble weapon... It entices its bearer into primeval forests, into mountains and deserts untenanted by man. - Horace Kephart
 
Posts: 6653 | Location: Switzerland | Registered: 11 March 2002Reply With Quote
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