A Data-Driven Approach To Precision Rifles, Optics & Gear
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Cal

Cal Zant is the shooter/author behind PrecisionRifleBlog.com. Cal is a life-long learner, and loves to help others get into this sport he's so passionate about. His engineering background, unique data-driven approach, and ability to present technical and complex information in a unbiased and straight-forward fashion has quickly caught the attention of the industry. For more info on Cal, check out PrecisionRifleBlog.com/About.

Lapua Brass for 7mm Rem Mag?

I shoot a 7mm Remington Magnum, and when I started handloading for it I began by looking for a high quality brass case.  I started by looking to see if Lapua made cases for a 7mm Rem Mag, and although I didn’t see any for sale through MidwayUSA or Sinclair … I did find some mixed opinions on whether Lapua had ever made cases for belted cartridges, and the 7mm Rem Mag in particular. Then earlier this year while I was at Shot Show, I was at the Lapua booth and noticed in their new VihtaVuori Reloading Guide they actually ...

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Barrel Length and Velocity

I recently had an opportunity to fire the same 223 Remington ammo over a chronograph out of 3 very different barrel lengths, and recorded the muzzle velocity differences I observed.  The chronograph was an Oehler 35p, which is one of the most accurate in the industry.  The ammo fired was Federal’s 55gr FMJ ammo, and all of it was out of the same box. Here are my measured results: Barrel Length (inches) Average Muzzle Velocity (fps) 20″ 3019 fps 16″ 2837 fps 7.5″ 2135 fps Here is an inferred trendline based on the measured velocities for other 223 Remington barrel ...

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Rifle Screw Torque Settings Guidelines

I’ve had to reference back to these torque specifications a couple times, and thought it’d be helpful to post. It is a list of the recommended screw torque settings for most rifle parts, like action screw torque. These come from a lot of different sources (including manufacturers on the phone), but one great one is Brownell’s “Torque Specifications for Gunsmiths” Article.  As that article explains, these specs are subject to change as companies change their manufacturing processes, materials, and design.  However, many people believe consistent torque is at least as important as the actual number of inch/pounds (especially when talking about action screws).  Here is an excerpt from that article that ...

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Oehler 35P Chronograph Manual

Oehler Research definitely makes the best chronographs in the industry … hands down, no argument.  I had a chance to talk with Ken Oehler at the 2013 SHOT Show, and have to say it was one of the most enjoyable conversations I’ve ever had with someone regarding ballistics.  Ken knows his stuff, and is an expert among experts in shooting sports.  I’ve used an Oehler 35P, which is the pro-sumer grade model they offer (i.e. model targeted at professionals or high-end consumers) and can say they are a joy to use … and VERY accurate.  You get very few errors and ...

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Long-Range & Short-Range Hunting Scope Combo Setup

Note: This post is about scope setups that can provide both long & short range capabilities. I also wrote a buyer’s guide for long-range scopes, which includes what features to look for and specific recommendations by price point.  You can find that here: Best Long-Range Scopes: Buyers Guide & Features To Look For. Lots of people have asked me about what the best scope setup is for a long-range rifle that they plan to take hunting.  The problem with most long-range scopes is that it can be almost impossible to engage targets that pop-up at close ranges unexpectedly.  Nothing is ...

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Best Long-Range Scope: Buyers Guide & Features To Look For

Advertising around long-range scopes can be misleading, or at least marketers try to get you to focus on features that differentiate them from their competitors … even if they aren’t really that important. I created this post to boil it all down to the biggest features you should focus on when comparing long-range scopes. Of course you are likely going to have to make trade-offs between different features, unless you are willing to pay $3,000+ for a scope (which many shooters do). But if you’re on a budget like most people, this list should help you make sense of all ...

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Berger Bullets Bearing Surface Variation

One of my friends recently told me they sort bullets by both weight and length of their bearing surface (the part of the bullet that comes in contact with the barrel, illustrated below).  I hadn’t thought of that before, but you could see how variations in the bearing surface length obviously impact the amount of barrel friction on the bullet and therefore cause variations in muzzle velocity. For virtually all of my precision shooting I use Berger bullets, and I wondered if there was even any measurable variation in their bearing surface because their quality control is so much tighter than other ...

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Detachable Magazine Dimensions & Max COAL

The table below contains the maximum Cartridge Overall Length (COAL) for popular detachable magazines for rifles.  This is important to consider when picking a rifle cartridge to ensure you have enough clearance to “chase the lands”, which just means as your chamber throat begins to naturally erode from use you seat your bullet further and further out so that it maintains the same relative position with the rifle lands.  Many people start with their COAL almost maxed out in their magazine, and as their chamber throat starts to wear they are forced to choose between loss of accuracy from not ...

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Portable Reloading Press Plans

I wanted to create a portable reloading press stand that I could mount my full-size RCBS Rockchucker Press or smaller RCBS Partner Press to.  The plans I came up with were simple to build, used easy to find materials, and the finished product has worked exactly like I was hoping.  The stand is very strong and stiff, which is critical when designing a reloading press mount.  It is ergonomic and natural to use on either a table top or a work bench surface.  I just use one or two Irwin Quick-Grip Clamps to hold it securely to the surface.  The stand has “window cutouts” ...

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7mm Rem Mag Load Development Part 4: 5 Shot Groups

I’ve already done quite a bit up to this point in my load development.  At this point I know I want to try to find an accurate load for Berger’s 168gr VLD over Hodgdon’s Retumbo powder and I’m now zeroed in on a very specific range of powder weights that seem to be very tolerant of slight pressure variances.  You can see the previous posts for how I got here. My next step is to test 5 shot groups in very granular powder increments. Jump to another step: Part 1: Bullet Selection & Real-World Velocities Part 2: Audette’s Ladder Test Part 3: Optimal Charge Weight Part ...

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