The Best .300 Win Mag Rifles Every Keen Shooter Should Know About

by Ben Jackson
Best 300 Win Mag Rifle

As long range precision shooters, we tend to be a little obsessive and methodical over every little detail when it comes to selecting the perfect weapon and equipment. This is understandable because we are trying to shoot very small targets that are so far away, you may not even be able to see them with the naked eye.

Military, Law Enforcement, and civilian marksman will all attest to using the proper ammunition for the proper application will make the world of difference when engaging a target at long range. It’s key to have the proper tools to increase your accuracy and land your shots on target.

With this information fresh in our minds, let’s break down the .300 Winchester Magnum and have a look at some of the best .300 Win Mag rifles and their applications.

.300 Winchester Magnum History and Design

The .300 Winchester Magnum, also known as the .300 Win Mag, is a bottleneck 7.62x67mm magnum rifle cartridge that was designed and introduced by the Winchester Repeating Arms Company.

The .300 Win Mag’s parent cartridge is the British .375 H&H Magnum (.375 Rimless Nitro Express,) the difference being the .300 cartridge has been tapered to handle the higher volume of powder, and the neck of the cartridge accepts a.30 (7.62) bullet, which allows for a higher muzzle velocity.

The only oddity in the design, in my opinion, is the shorter neck of the round requires the bullet to sit deeper in the cartridge, which some experts would say this is a ballistic flaw, but in my experience, I haven’t experienced any malfunctions associated with this.

.300 Winchester Magnum Ballistics

The height of the .300 Win Mag cartridge is 2.62”, the width is 0.532”. The overall average load is 150-173 gr. The average velocity is 3,000 feet per second, and the energy distribution is 4,877 joules.

The .300-win mag burns twenty to twenty-five percent more powder than rounds similar in size and weight. This extra propellant adds an eight to ten percent increase in muzzle velocity. However, increase power and muzzle velocities do come with a drawback in terms of recoil.

The average rifle weighs about 11 pounds, so say we’re firing a round with an upper limit load, like 180 grains, your shoulder is going to get smacked with 40 lbs per square foot of recoil energy so be prepared for recoil and ensure your rifle has a good butt pad. Fortunately, most rifles feature some sort of proprietary recoil reduction system to slightly mitigate the recoil.

The maximum point-blank range with no hold for the .300 Win Mag is approximately 250-300 yards, and the maximum long-distance range can reach distances of up to 1,200 yards depending on the grain load and cartridge used.

Before we go any further, let’s talk about the basics of ballistic coefficients and why the .300 Win Mag is a popular choice.

Individual ballistic coefficients make a significant difference in determining which round is best for different applications. The higher the ballistic coefficient, the flatter the trajectory will be and greater energy retained down range on at the point of impact.

The ballistic coefficient is the principle of measuring a bullet’s relative velocity required to overcome air resistance. Every round is assigned a numerical value which determines its individual efficiency. Ballistic coefficient calculations combine factors of each rounds shape, sectional density factors, bullet weight, and the grain count of the powder.

The .300 Win Mag’s muzzle velocity with 165 grains, zeroed at 275 yards is 3,035 FPS, with an impact force of 3,375 F.T.LBS at a target set at 100 yards.

At 200 yards, a muzzle velocity of 2,822 FPS, an impact force of 2,917 F.T.LBS.

At 300 yards, a muzzle velocity of 2,618 FPS, an impact force of 2,511 F.T.LBS.

At 400 yards, a muzzle velocity of 2,424 FPS, an impact force of 2,148 F.T.LBS.

Say our marksman is engaging a target up to 500 yards, the flatter trajectory of the 165 grain .300 win mag round would be ideal. For targets 600 yards or further, the marksman may consider using a load that offers a superior ballistic coefficient, such as the heavier, harder hitting 200+ grain loads.

Essentially, the heavier bullet weight, the longer and flatter the trajectory will be. The correct bullet selection is very important when using this caliber. Granted, there are numerous environmental factors a marksman must consider when taking long distance shots; nevertheless, having the round with a superior ballistic coefficient will reduce the chances of throwing a shot.

The .300 Win Mag offers many amazing solutions to the shooter that other calibers in the .30 caliber class. The .300 Win Mag can take down a bear from 500 yards with the appropriate ammunition.

That’s where education and research makes it shooters preference. I personally think these rifles are the some of the most accurate and precise weapons on the planet. I would trust any one of these weapons to make a shot at seemingly impossible distances if my life counted on it.

Sporting Applications of the .300 Winchester Magnum Round

The popularity of the .300 Win Mag has grown with North American hunters through hunting large ungulate animals, like elk and moose, which can easily weigh up to a thousand pounds.

Ammunition manufacturers realized the increasing trend so most began offering specialized rounds which feature controlled expansion bullets with a heavier bullet weight (200 gr) per round, which are much more effective than a lighter round (130-150gr), which are better suited for smaller game. For more dangerous game such as bear, there are 220 gr loads that have been said to take down targets quickly with proper shot placement.

Say you’re a hunter and you want to hunt antelope and whitetail deer, proper bullet selection is imperative when using the .300 Win Mag because the shooter will have to compensate for the extra two hundred to three hundred extra feet per second when shooting a target which a lightweight round can glance off bone and flatten, ruining the meat of your hunt.

A heavier bullet with a lower velocity is ideal. On a hunting trip several years ago, I shot a whitetail deer with a Hornady 150 grain GMX, which put a tiny hole straight through its torso, without spoiling any of the meat.

However, when hunting large game like bear, you will need a high-velocity round that can expand and cavitate when it impacts flesh to cause more damage, effectively killing the animal as quickly as possible.

The Best .300 Win Mag Rifle

Kimber 8400 Advanced Tactical SOC

Kimber is known between firearm enthusiasts for producing some of the best 1911 handguns in the world. Believe it or not, Kimber also produces a line of high-end precision rifles. The 8400 Advanced Tactical SOC rifle is a special operation capable precision sniper rifle designed with both tactical and sporting applications in mind.

The SOC combines long range precision accuracy with various tactical features for long range shooting.

  • The Advanced Tactical SOC comes chambered in .300 Win Mag, weighs in at 12 pounds, and features a Kimber proprietary designed aluminum chassis system, the Kimber Modular Chassis System, with a 1913 Mil Spec Std rail with a keymod attachment system for attaching optics, and multiple tactical accessories to the top and fore-end of the weapon.
  • The stock is a side-folding aluminum and polymer with an integral monopod that provides additional stability when working with a bi-pod. The stock features an adjustable length of pull and an adjustable cheek comb. A Harris bipod adapter comes mounted on the weapon.
  • The barrel is a four-groove match grade heavy barrel with Kimber’s self-lubricating matte KimPro ll finish. The overall barrel length is 27 inches with a 1:12 twist rate with a SureFire muzzle break that can accept quick attach suppressors. The adjustable trigger comes factory set 3-3.5 lb. with a Model 70 3 position safety. The action of the 8400 SOC is a front locking repeating system with a Mauser claw extractor.
  • The Advance Tactical SOC has sub .5 MOA accuracy at 500 yards, the rail system is set at 20 MOA, so optics can be easily adjusted for 1,000 yard shots. The oversized knob on the bolt handle makes manipulation of the action easy when wearing gloves or for night operations. The Kimber’s steel floor plate assembly can take a serious beating compared to weaker aluminum floor plates that are found in a majority of factory precision rifles.

McMillan TAC-300

The McMillan TAC-300 is a heavy barrel bolt action precision rifle chambered in .300 Winchester Magnum. McMillan has become legendary amongst special operations and military units throughout the world, notably in the Middle East and abroad during the war on terror.

In the past decade, several of the longest recorded shots in history were made by snipers using McMillan rifles. Even under the most extreme conditions, McMillan rifles deliver superior accuracy and reliability.

  • The McMillan TAC-300 weighs 11 pounds, and the length is 47 inches. The stock of the rifle is constructed out of A-5 fiberglass, features a G-30 McMillan Action, a 26-inch match grade polygon rifled heavy barrel with a 1:11 twist, and a Remington style trigger which is set at a 3-lb. trigger pull. The 26-inch barrel is also threaded and comes with a screw on cap.
  • The stock of the McMillan TAC-300 is constructed of A-5 fiberglass and features an integral adjustable cheekpiece so the shooter can adjust the comb of the stock to keep the shooters eye at optic level. Adjusting the comb is simple, just twist the knob on the right-hand side of the stock. The McMillan A-5 stock also features an adjust length of pull (LOP) option so you can comfortably seat the rifle in your shoulder regardless of your arm length. The spacer system can be adjusted from 13 inches to 14 and a half inches, all you need is a 5/35 Allen wrench to remove any of the four rubber spacers to the desired length.
  • The TAC-300 comes with a variety of accessories like a Leupold Mk-4 8.5-25×50 M1 Mil Dot scope, a 1750 Pelican Case, Badger Ord. 20 MOA Long Action Base, Badger Ord. Med-High 30mm Rings, Harris HEBR 6”-9”  Swivel Bipod, a Turner Saddlery Synthetic Leather Sling, McMillan Rifle Cleaning Kit, 3-5 round .300 win mag magazines, and McMillan Drag Bag. Additional upgrades that can be purchased directly from McMillan include an illuminated scope receptacle, McCann night vision rail mount, Night Force 8.5-32x56mm Mil Dot, Elite Iron suppressor, Elite Iron muzzle break, and a Jewel trigger.  

NEMO Arms Watchman 2.0

The NEMO Arms Watchman 2.0 is a very impressive self-loading precision semi-automatic rifle that has been built around the less popular big brother of the AR-15, the AR-10 platform, and transformed into a heavy, hard hitting rifle chambered in .300 Win Mag.

  • The rifle weighs in at 11 pounds and 46.25 inches long with a 7075 billet aluminum machined upper receiver, a 24-inch match grade 416 stainless steel barrel with a 1:8 twist, and a nickel boron plated barrel extension. The bolt system is a nickel boron bolt carrier group with a billet machined high strength steel side charging handle and a nickel boron bolt release.
  •      NEMO Arms changed the perception of self-loading precision rifles by designing the Watchman 2.0 with feedback from soldiers who fought in the Middle East. The gas block of this weapon is the NEMO Adjustable Gas Block System which features NEMOs own patent-pending Recoil Reduction System with a SASS barrel taper, which can be adjusted to accommodate firing various types of ammunition and suppressors. With a turn of the regulator at the fore end of the rifle, you can adjust the weapon to use more or less gas to optimize your rounds ballistic coefficiency.
  •      One thing I noticed immediately about this rifle is it feels so natural if you’re familiar with AR-type rifles. The ambidextrous safety selector switch and mag release are where they should be. The octagonal forearm free floats on the Watchman 2.0’s hand rail is surprisingly comfortable and slim to grasp without fatiguing. The stock of the Watchman 2.0 is a Magpul PRS sniper stock and the grip is a Houge over molded pistol grip.
  •      There’s a full-length Picatinny rail on the top of the weapon for mounting any in front of the scope accessories. The rifle comes with two small sections of Picatinny rail and threaded screw holes on the sides of the weapon to add sections of rail if you want to bolt a light, laser, or bipod to the weapon. Mounting the accessory rails onto the weapon doesn’t require a gunsmith or specialized tools.    

Remington MSR

In 2009, The US Special Operations Command launched the Precision Sniper Rifle Program that would replace all bolt action sniper rifles with a single, modular sniper rifle that can be chambered in Magnum calibers like .300 Win Mag and .338 Lapua mag.

The criteria set for the PSR Program listed a number of requirements for the replacement sniper rifle, such as sub-MOA accuracy between 300-1500 meters, can be disassembled and reassembled in under two minutes with no change in the weapons zero, an overall length of 52 inches or less excluding suppressor, 18 lbs or less fully loaded, and a mil-spec Picatinny rail on top of the rifle.

After a long competition with various weapons test, the Remington MSR was awarded a $79.7 million for 5,150 rifles and 5 million rounds of ammunition until 2019-2020. The MSR, or the Modular Sniper Rifle, was designed with 100% military application in mind but Remington Defense now produces the MSR for civilian marksmen as well.

  •   The MSR features a billet titanium receiver with a steel locking nut that can be removed to swap barrels and switch the caliber of the rifle. In less than one minute. By changing the bolt face, barrel, and magazine, the operator of the rifle can change the cartridge from .308 to .300 Win Mag, to .338 Lapua without any gunsmithing. The MSR bolt features three interchangeable radial locking lugs that provide a 30% shorter bolt throw compared to the standard 90% bolt throw.
  •   The 20 inch .308 rifle barrel features a 1:11 twist, 24 inch .300 win mag barrel features a 1:10 twist and the 27 inch .338 Lapua mag features a 1:9 twist. Each barrel is match grade with a surface hardened Melonite finish. Each barrel is treated to reduce friction and surface wear throughout the barrels life.  
  •   To accommodate various caliber magazines in the mag well, Remington includes a magazine block to accommodate the shorter action .308 cartridge. The MSR magazines are manufactured by Accuracy International and the .308 holds ten rounds, the .300 Win Mag holds five rounds, and the .338 Lapua has a five-round capacity.

Accuracy International AXMC

Accuracy Internationals rifles are used by over sixty worldwide militaries and law enforcement agencies because of their rifles ruggedness and unprecedented accuracy. Much like the Remington MSR, The Accuracy International AXMC was designed based on the selection of U.S. Special Operation Commands “Precision Sniper Rifle” program.

The Accuracy International AXMC stands for AX multi-caliber because of the chassis ability to change barrels and the caliber of the rifle based on the application of the rifle. This lightweight, durable rifle offers un unprecedented accuracy at distances of up to 1000 yards.

  •   The overall length of the rifle is 41.5 inches and the weight is 12.4 lbs. empty. The barrel length is 20 inches and has a 1:9 twist. The QuickLoc barrel release system makes swapping barrels in under a minute effortless, all that’s needed to do so is a 4mm hex wrench, which is included in the stock of the rifle. Suppressors can be attached by unscrewing the thread protector at the end of the muzzle break, of by unscrewing the muzzle break itself and attaching the suppressor directly to the end of the barrel.
  •   This rifle features an aerospace grade aluminum chassis system and a full-length NATO  Mil Spec Std 1913 rail system that’s contoured to the action of the weapon for mounting accessories, night vision scopes, and optics. The rail system is inclined to 20 MOA for .308 ammunition, and 30 MOA for .300 win mag and .338 lapua.
  •   The folding stock is constructed of alloys and a composite polymer that incorporates a friction locking mechanism which can be configured to several LOPs, and the comb of the cheek piece comb can be moved depending on the height of the mounted optic without any tooling. The pistol grip of the AXMC can be changed and swapped with any AR style grip.
  •   AXMC features a two-stage adjustable trigger that can be adjusted by any gunsmith. Accuracy International incorporated their three-position safety system that’s been used in the battle tested Artic Warfare rifle throughout the years. Swapping magazines in the AXMC is simple, the shorter action .308 magazine requires a magazine adapter that snaps directly onto the magazine.

You can see from the few .300 Win Mag rifles we’ve discussed today, there isn’t a shortage of amazing, high end precision rifles on the market. I’ve learned from my personal experiences that it’s more so the marksman and his intuition and skill level, more so than it is the weapon that makes the bullet go where you want it to.

This is the concept and philosophy of long range marksmanship. Every aspect of the weapon and present conditions and variables must be perfect to master this craft.

If you’re a beginner and you’re unsure of where to start, go out to your local gun range and, budget permitting, test out any one of these weapons and see which one feels natural to you. If you feel like you’re advanced enough, check out the multi caliber rifles and experiment with swapping the barrels out and maintaining perfect zero and adding different variables to account for.

Don’t allow yourself to become complacent, practice yourself, challenge yourself to make a seemingly impossible shot from a very long distance. Rest assured that any one of these rifles are beyond capable of performing whatever task you need them to. Happy Shooting.

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