SKU: 3270725055

Superior Shooting Systems Distance Reduction Indicator

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Description

Superior Shooting Systems Distance Reduction IndicatorWhen firing up or downhill, an uncorrected aiming point results in a high shot. The shooter must hold less elevation than the same shot fired across level ground. Knowinghow much higher the bullet will impact becomes increasingly important as the distance to the target is increased, or as the angle becomes steeper, or both. David Tubb's Distance Reduction Indicator (DRi), quickly and accurately indicates this "Hold Closer" distance and allows the

When firing up or downhill, an uncorrected aiming point results in a high shot. The shooter must hold less elevation than the same shot fired across level ground. Knowinghow much higher the bullet will impact becomes increasingly important as the distance to the target is increased, or as the angle becomes steeper, or both. David Tubb's Distance Reduction Indicator (DRi), quickly and accurately indicates this "Hold Closer" distance and allows the shooter to determine the Effective Hold Point (EHP) to make an accurate shot. The DRi is usable at any realistic distance.

The DRi eliminates the need for cosines as well as angle measurement.

The DRi is compact and rugged. It's engineeered to be low-profile and constructed to withstand the rigors of field use. The DRi fits any standard Picatinny rail, and is level-adjustable over a 100-moa range to accomodate long-range-style scope mounts. With laser engraving along the side of the dial the DRi is also readable from the spotter's perspective.

How it works

The DRi base is marked with "6" "9" and "12". These numbers correspond with 600, 900, and 1200 yards or meters. TheDRi is equally accurate using yards or meters.

The DRi dial has markings that correspond with theDistance Reduction markings on the base. The "6" and "12" have numeric values, the "9" splits the 6 and 12 values and is used to average/interpolate. The large numbers on the dial indicate the hold-closer distance in yards or meters. Mounted correctly, the user can acquire the DRi and then reaquire the sight with a minimum of movement.

DRi In Use

*To determine the effective hold point (EHP), follow these steps:

1) Determine the straight-line distance to the target.

2) Aim the rifle at the target (this step engages the DRi to provide a read)

3) Determine EHP (effective hold point) for your distance.(This step can involve simple mathematical calculationsfor varying combinations of distance and angle.)

4) When you have determined the correct EHP, locate the appropriate aiming dot within the scope, or adjust the scope knob.

The DRi difference

Rifle mounted "angle indicators" and "cosine indicators" are on the market to determine the Effective Hold Point (EHP). "Angle indicatos" give their answers in degrees of angle (ex. 10û) which then must be input into the user's ballistic card/data program to determine EHP. "Cosine indicators" give their answers by allowing the user to read a percentage (ex. 96%). The shooter then multiplies this percentage by the target distance to determine the effective horizontal distance to the target. That all takes time and, in the case of the cosine calculation, it's not very accurate at longer ranges.

The DRi eliminates the need for angle measurements and cosines. The calculations are simple, and the inputs are fast, direct, and accurate. Under stress and time pressure, the DRi provides the fastest, most accurate angle firing solution.

We recommend positioning the DRi so it is easily visible from the shooting position. This improves efficiency in reading the DRi and reaquiring the scope.

The DRi is complete and ready to go out of the box!!!

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SKU: 3270725055

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cloud-learner
Natrona Heights, US
★★★★★ 3
have some good contents but too general
Format: Paperback
The book covers some good points, but overall, it's too general.
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Reviewed in the United States on June 28, 2024
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Engineer Dude
Bozeman, US
★★★★★ 3
Why Politics in a Tech Book????
Format: Kindle
Well... I'm surprised to see the book blatently calls out its dedication to Black Lives Matter, which is in all caps so I assume it's referring to the political organization. It goes on to speak of 2020 being the year of an "awakening of injustices of systematic racism"... I thought I was buying a technical book??? Had I known this political bs was included I wouldn't have purchased it! However, I bought and I'm still reading it. If the politics goes away and the TECHNICAL content is good I'll update my review.
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Reviewed in the United States on December 13, 2020
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PeaceBee
Pawtucket, US
★★★★★ 2
Not good use of time
Format: Paperback
It’s not clear who this book targets - neither experts nor novice will benefit. There are expert perspectives, only few of these are helpful, rest are too generic to be of any use. For instance the last entry is one an engineer who shares how she went from zero to expert in cloud engineering in six months but fails to mention a single resource or pathway for others to follow.
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Reviewed in the United States on April 2, 2022
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Nilendu Misra
Phoenix, US
★★★★★ 3
Uneven compendium of tips and insights, but still very useful
Format: Kindle, Format: Kindle
“In theory, theory and practice are the same. In practice, they are not" is why such bottom-up insights and lessons from the field are the fastest way to learn real life stuff. This series had a GREAT start with "Engineering Management" - I guess because it is way more subjective than Cloud Engineering and offered a variety of non-overlapping POVs. This one is a mixed bag, perhaps because "Cloud Engineering" was perceived amorphously by the authors. The scope was broad - from cloud-native (architecture), to cloud-ready (topology), to cloud-operations, to choosing tech (e.g., Lambda/serverless), to -ilities and economics -- it is like celebrating Halloween, Christmas and Labor Day together in a single long weekend. I would give it 4/+ stars if at least 25% of such a book was "superb", giving 3 because about 10% of the book is. That still leaves 10 solid insights or learning that would otherwise take many failures to learn. And failures, especially in this emerging domain of complexity, is VERY expensive. Would love to see more books like this. Let's summarize some key insights - -- Real-time visibility across the entire DevOps lifecycle is key to winning in cloud. -- Operations, especially operations at scale, is extremely hard. So, wherever possible, use Managed Services. -- Distinguish between "availability" and "uptime" and measure each separately, and concretely. -- In FaaS/Serverless, calling a function synchronously increases debugging complexity. -- Good code is like good joke - it needs no explanation. -- "Building your app or platform on top of the abstractions that a cloud provider gives you does not make the underlying layers stop existing. In many cases, it makes them even more important." That makes the failure modes LESS obvious than we were used to. Therefore having "extreme visibility" into your systems will help "separate the issues at the layer you're focused on from the fundamental system issues". i.e., just because what was under the hood is now even less visible, don't forget them. Many recent "cloud failures" have been in networking fault domains. -- Cloud is not optimized for replacing static infrastructures. -- Containers, service meshes and serverless jumpstart dev productivity but they also change the attack surface of apps and infra. -- "Number of containers that are alive for 10 sec or less has doubled to 22%". 73% of all containers live for 30 minutes or less. -- Adopt an "assume breach" stance for everything. Have a break-glass account. -- Ensure you have a thorough understanding of where and how secrets are secured. -- Grey failures (transient degradation of services) are often worse than complete crashes, since the latter have a short feedback loop. -- Resilience engineering has existed as a sub-discipline within safety sciences. We just recently started applying its concepts in technology. Resilience can be thought of as a "socio-technical system" with Robustness ("system X has property Y that is robust in sense Z to perturbation W"); Reliability (consistent operations or service levels); Rebound (ability to deal with a chaotic situation using structures developed AND deployed BEFORE the chaos). In other words, robustness protects systems against a SPECIFIC type of failure mode. When a system is robust in many dimensions, it approaches good resilience to failure. -- Resilience is something you "do", not something you "have". Resilience is a verb. -- Moving from one class of nines to the next is 10 times more expensive. -- Production System really means "system that someone else, anyone else, can hold you accountable for". -- Most common theme across incidents is that something, somewhere was surprising. -- Incidents are unplanned investments...your challenge is to maximize ROI. -- We used to think of scale in two dimensions - horizontal (more) and vertical (bigger). In cloud, think of "scale out" (when demands increase) and "scale in" (when demand decreases). -- Architecture diagram is also a map of failure modes. -- Async communication is a friend of Cloud Reliability. -- Test in production is a competitive advantage. The complexity of traffic patterns going through high-scale production systems is increasingly harder to reproduce in a controlled env. -- Hundreds of open issues is fine, but if the repo has gone months (or, years!) without a release, THAT is a warning sign. -- It is hard to write good tests for bad code. -- Platforms come and go. But first principles and patterns will always exist, because they are the ones and zeros.
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Reviewed in the United States on November 6, 2023
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M. Klocker
Louisville, US
★★★★★ 2
Shallow, biased and significantly overpriced
Format: Paperback
Well, this purchase was a disappointment. 20% of the pages are dedicated to just highlighting the bios and backgrounds of the many different authors that contributed this great wisdom. And let me be clear, the authors are solid. They are professionals with credible backgrounds and experience. But it's the format and constraints of this book that makes it virtually impossible for that to shine through. Because the rest of the book (80%) is dedicated to the so called "97 things every cloud engineer should know". And unfortunately the average length of one of these "things" is about 1.5 pages long, and as such extremely shallow and in about 30% of the cases straight up promotions for specific company services. You will find Google cloud advocates telling you to use managed services, of Google of course. AWS engineers telling you to avoid them and use IaaS. LaunchDarkly employees telling you to use feature flags. The list goes on. The TL;DR: here is that if you have built anything on the cloud in the last 2 years, this book is going to be a waste of your time and money. You are better of googling: "cloud best practices" and dedicating 2h to reading the first 10 non-ad related search results.
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Reviewed in the United States on March 23, 2022

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