Joining The CRPS – Optics (Part 3)

Gear Getting Started Optics Uncategorized

 

This is the third installment. We are going to discuss optics. I am not an expert on the matter. In fact I have learned a great deal on this journey of building this “Long Range” lead slinger. There is a lot involved in pushing the .22 LR cartridge to the distances that we are in the CRPS course of fire. So much so that I will be splitting this topic into two segments.

In this first segment we will discuss what features to look for when selecting your scope. In the second segment we will discuss how to optimize your selected scope to push that little piece of .22 calibre lead out to 300m.

Scope Selection

Being in the “Production Division” of the CRPS make the Budget question pretty easy. “Don’t spend more than $500 MSRP and you’re good to go!” Seemed easy enough. Boy was I wrong. The under $500 segment of the optics industry is quite vast. Each scope come with their own plethora of options and hype. It’s pretty tough to narrow it down to only a handful of options. So in order to give you a hand, here are some features you may find useful.

Turrets

Common turrets found on most scopes used for hunting applications. They are useful for a “set and forget” style of shooting”. Not ideal for PRS.

Due to the nature of the multiple distance engagement of the CRPS, you will be “dialing” your scope often. Standard hunting scopes may fall short in this department. You will need a well marked turret that you can turn easily without the use of tools. The markings will help you keep track of your current “location” in regards to your windage or elevation.

The turrets should have a solid feeling “click” when you turn it. It should not feel loose or mushy as you turn the turret. It is a definite bonus if there is an auditory “click”. This is not a deal breaker, but it allows you to hear an auditory confirmation of your adjustment and keep your eyes on the target.

This Vortex scope has well indicated turrets. It helps keep track of adjustments when transitioning from target to target.

 

MOA/Mil

I thing this is more of a personal preference. Kind of like the metric and imperial system of measurement. Both will get you where you need to go. What is important is the increments of adjustment.  1/4 MOA is fine enough for the CRPS. If the adjustment is too fine, you will be endlessly turning your turrets to get on target. Too course and you will may be shooting to high/low on small targets.

Range of Adjustment

Each scope has a limited amount of adjustability in elevation and windage. Often, the advertised amount of windage/elevation is not what you will actually experience. You may end up with a little more or a little less. In order to determine what your scope actually has, you will need to spin your turrets all the way down (don’t force the turrets. Stop when you begin to feel resistance). From there count the amount to clicks to get to the top end. If you know how many mils/MOA per revolution, it can save you lots of counting. Usually scopes with lower magnification ranges have more range of adjustment.

Due to the ballistics of the .22LR cartridge, you will need a great deal of adjustment. Some of the #’s coming in from the facebook group is 52 MOA (40gr travelling at 1110 fps). This is just a suggestion. This only accounts for the ballistic drop of the bullet and does not take into account where you rifle is zeroed within the scopes range of adjustment. Lots of the guys are talking about needing more elevation with their current setups. We will talk more about how to squeeze more elevation out of your optics in the second segment.

Reticle

Standard “duplex” reticle. May be difficult to have consistent “hold-overs”.

There are a wide variety of different reticles on the market. It seems each manufacturer has their own unique offering. For this article I will keep it simple and overly simplify this. There is a basic duplex and models with “hold-overs” or marked lines or grids.

If you have a basic duplex, you will be dialing a little more often. You can incorporate a little “Kentucky Windage” and hold the target into the empty void on the reticle. However, this is not the most repeatable nor scientific method of getting a little more elevation or quick target acquisition.

By using a reticle with hash marks (or hold-overs) it gives a more repeatable method by providing a visual reference point to hold the target within the reticle. Do not rely on the “BDC” (bullet drop compensation) feature that most manufacturers mention. It is very dependant on the bullet’s weight and velocity, therefore your results at vary greatly dependant on your selected ammunition. Example; if your scope’s BDC was calibrated with a 40 gr bullet traveling at 1250 FPS and you are shooting a subsonic 40 gr bullet traveling at 1050 fps, the manufacturers suggested hold-overs will be substantially off the mark.

Magnification

The “Aim small, miss small” mantra doesn’t really apply to the fast-action, multiple distance engagement of PRS style shooting. Too much magnification and you will waste time searching for the next target in the stage. Too little of magnification and your reticle may cover the target.

The sweet spot seems to be around 3-9x. This is a good thing because it is one of the most common magnifications available. According to match directors, the targets at the extreme distances are approximately 18″X30″ and 24″x12″ in size. If you have a little less or little more magnification, it is not a deal breaker. Just run what you are comfortable with.

Parallax

“Rifle scope parallax is a known optical illusion where the target looks out of focus and the focal plance of the target is offset from rifle scope reticle. It is the apparent movement of the reticle when the eyes move off center of the sight picture.”

To combat issues with parallax manufactures have essentially two options, fixed and adjustable. Fixed parallax is when the parallax correction is set for a specific distance. One most centre fire rifle scopes it is 100 yards. With rimfire scopes it is usually  50 yards. The other option is an adjustable parallax. This option comes in two flavors. Adjustable Objective and Side Focus. For PRS style shooting the side focus models are more desirable because it is faster to access the knob located on the side of the scope rather than having to reach over the scope and turn the Objective lens.

Glass Clarity

This is as simple as it sounds. Where glass clarity or lack there of begins to manifest itself is when you start raising the magnification. Any issues with the glass will be enhanced. Issues like “fogginess” at high magnification are common with really cheap quality glass.

 

At the end of it all, the best thing you can do is go to your local gun store to physically see and hold them in your hand in person Look through them. Twist the turrets, Zoom in/out, ask the staff questions. Do your research on line. See what others have to say in the facebook group.

 

 

My Build

Vortex Diamondback Tactical 3-9×40 is what is going on my current CRPS production build.

I decided to go with the Vortex Diamondback Tactical 3-9×40. It used to reside on top of my “Precision Scout Rifle” (a Mossberg MVP Scout sitting in a MDT LSS Chassis).  I chose to use it because it checked off a lot of the boxes of an ideal production division scope. It had “tactical turrets” and 80 moa of internal adjustment (windage and elevation). I am hoping with that much internal adjustment that I will not need a canted rail. It does lack a parallax adjustment, but has a factory calibrated parallax for 100 yards. I am hoping that if I can maintain a consistent cheek weld and sight alignment I should be fine.  It also had a reticle with hash marks. Best of all it was under the $500 limit.

I may be  overly optimistic about this setup, only actual “in field” testing will show the true compatibility of this scope for the “precision rimfire” application.

————— Update April 18th,2018 ————-

The marlin is starting to take shape. Bushnell Elite 10x with a DIY Cheek Riser and cheap Amazon bipod.

One of the members of the facebook group told me that he visited the Vortex Canada website and the published MSRP for the Diamondback Tactical was $549. The “street price” however is around $399. This was something that needed to have clarification from the CRPS. After weighing in on all the details, they reached a decision and will continue to use MSRP as a guideline.

So, I am currently switching over to a borrowed Bushnell Elite Tactical 10×40. It only has 50 MOA of adjustment so I may need a canted rail in order to “go the distance” on some of the farther stages. I also had to build up a cheek weld using foam and camo tape. It should hold up at least for a few practices and one event.

 

In the next post – Part 3.5, we are going to talk about Rings, Adjustable Rings, Rails, Canted Rails, Shims, and Bubble Levels.

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