April 18, 2018
We were initially skeptical about Savage Arms' decision to start making AR-type rifles. There are already so many available that we hardly see the need for more. But, we quickly became a believer after testing both AR-15 and AR-10 styles and considering the performance they offered for the small price they command. It is our opinion that no AR offers more accuracy for less cash than Savage's AR-15 pattern rifles.
We didn't hold out much hope that Savage could pull off a similar upset with its large-frame, AR-pattern rifle, the MSR 10. The large ARs are far from new, and a lot of subtle improvements have made their way to just about everybody's rifles, so it's hard to stand out in the crowd. Not only does Savage stand out, they offer quantifiable performance enhancements beyond accuracy - and they do it for considerably less than the competition.
Reciprocating mass is one of the most overlooked aspects of any direct-impingement, AR-pattern rifle. Yet, it tells us the most about whether or not an AR is gassed correctly. Almost every large-frame AR out there is over-gassed and has more reciprocating mass than necessary. This translates to increased parts wear, premature parts breakage, and unnecessary recoil. The Savage MSR 10 Long Range has none of these issues.
Years ago, G&A's Tom Beckstrand started measuring weights on bolt carrier groups in large-frame ARs as they cycled through these pages for testing. Most adhere to the standard weight laid down by Eugene Stoner of 19 ounces. High-end manufacturers have done thousands upon thousands of rounds in testing similar rifles and came to the conclusion that 19 ounces is way more weight than necessary. We agree.
Most AR manufacturers use massive carrier groups because they are readily available (few actually make them in-house) and to "mass regulate" the port-pressure-sensitive 7.62 NATO round we usually find in large-frame AR-10s. (Every other cartridge gets to use whatever works best for the 7.62. Economies of scale are so cruel).
The 7.62mm ARs shoot a wide variety of bullet weights using a lot of different powders, and each combination creates a different pressure at the gas port based on the powder type, burn rate and bullet weight. The simplest way to deal with the wide variations in port pressure is to make the carrier overly large and push it with a lot of gas. This is a very crude solution, but big, heavy carrier groups will almost always be slow enough to extract and cycle reliably.
One of the first things Beckstrand did with this rifle was to pull the bolt carrier group (BCG) out of Savage's MSR 10 Long Range and throw it on a scale. The scale would tell us in no time flat how much effort Savage put into designing this rifle or if they're just selling a "me too." We were impressed to see a svelte "15.5" ounces display on the digital readout (14 ounces is as light as we're comfortable seeing for any large-frame duty rifle). This rifle just got a whole lot more interesting.
Curiosity officially piqued, and we looked to the next critical component for any direct-impingement AR: the buffer. Few rifle parts are drabber than a buffer. It hides in a tube, looks odd and makes funny noises when you shake it. Its weight is also a critical component to reliability.
Like the BCG, the standard answer is to pump a ton of gas through the rifle and use a heavy bolt carrier group and buffer to prevent the extractor from slipping off the fired case's rim and to keep the cam pin from beating on the bolt. Buffers weigh anywhere from 3 ounces up to 10 ounces.
The MSR 10's buffer weighs 3 ounces. That means the designers at Savage knocked 31/2 ounces out of the bolt carrier group and used the lightest buffer available in this rifle. Losing 31/2 ounces might not sound like much, but it's a huge difference for a bolt carrier group. Recoil is much lower than you'd expect and these weights are a prime reason why. The life of this rifle's parts is also going to be longer than you'd expect because the MSR 10 doesn't rely on high pressures to cycle the action. The reason Savage engineers could pull all of this off is due to the extra-long gas system and adjustable gas block that comes standard on the Long Range model.
Lengthening a gas system is like giving an AR Xanax; it mellows it out. Not to get too far into science, but Boyle's Law states that the pressure of gas increases as the volume of the container decreases.
Lengthening a gas system pushes the gas port further down the bore. Since the action doesn't cycle until the bullet passes the gas port and pressurizes the system, the entire operating pressure of a longer system is much less than that of a shorter system. Those extra inches of bore give the gas behind the bullet that much more room to expand (like a bigger container) and drop in pressure.
Savage decided to hang as long of a gas system as would fit on the MSR 10 Long Range we've tested here. It is a couple inches longer than a rifle-length system and drops the port pressure significantly. The gas system on this model measured 15 inches. (That's the distance between the gas port and upper receiver.) It would be impossible to stretch the gas system any more than this.
An argument with which some will be familiar is that lowering the port pressure will also decrease bolt velocity. While it sounds good, the empirical evidence indicates otherwise. Compare Colt's carbinelength gas system's cyclic rate to the cyclic rate on their mid-length gas system. The mid-length should have a slower cyclic rate, but it does not. Both are the same.
Rifles with a low port pressure can still have high cyclic rates if the gas port is big enough. The important rule to remember is Boyle's Law because as the gas system length increases, pressure drops everywhere - including the chamber.
Pressure in the chamber pushes the fired case into the chamber walls. The higher the pressure, the more the case wants to stick. That "stick" is what the extractor, bolt and cam pin must all overcome to pull the fired case out of the rifle and eject it. The shorter the gas system, the smaller the container and the more resistance the rifle has to overcome.
Savage's gas system is as long as they get, and internal pressures are as low as they come. That's how they can keep the bolt carrier weight lighter than everyone else's and still use a three-ounce buffer for reliable operation. It's one of the most elegantly designed gas systems we've tested, and the only other ARs with something similar cost $1,000 more with a waiting list several months long.
Barrel & Gas Block
Just like the MSR 15s that Savage put into production in 2017, the MSR 10 has a barrel and gas block produced in-house. The Long Range has a 22-inch, button-rifled barrel that is finished in Melonite QPQ, a finish that converts the barrel's surface instead of placing a coat over the top of it. The barrel measured .92-inch in diameter under the handguards and then dropped to .75-inch forward of the gas block. There are six heavy flutes that span the barrels length under the handguard.
The Long Range in 6.5 Creedmoor benefits from the SAAMI chamber specifications of the cartridge. The 6.5 Creedmoor was designed from the start for accuracy. One of the secrets of the 6.5 Creedmoor chamber dimensions is the free bore diameter. Since the 6.5 Creedmoor is a relatively young cartridge, its development was aided by the tribal knowledge manufacturers have amassed. The 6.5 Creedmoor chamber was also able to take advantage of the incredibly tight tolerances now commonplace with modern manufacturing techniques.
The free bore of any chamber is the part of the barrel where the bullet sits once the cartridge is chambered. Free bore is a smooth round hole that guides the bullet into the leade and rifling. The 6.5 Creedmoor has a bullet diameter of .264 inch and a free bore diameter of .2465 inch. That means there's .00025-inch clearance on either side of the bullet once the round gets shoved into the chamber (provided the manufacturer stays on top of their tooling).
The 6.5 Creedmoor wants to shoot very accurately because the chamber dimensions are so well thought out. There is very little room for the long projectile to yaw prior to engaging the rifling, so it enters straight and exits the muzzle straight.
The twist rate on the 6.5 Creedmoor Long Range is the standard 1:8 inches that does so well with the long and heavy bullets common for this cartridge. Most 6.5 Creedmoor loads use bullets weighing anywhere from 120 to 147 grains, and the 1:8-inch twist can easily handle them all.
As soundly designed as the gas system and barrel are, the adjustable gas block is no less elegant. It is a simple screw held in place with a ball and detent that can be adjusted in quarter-turn increments. The screw threads into the gas block parallel to the barrel from the muzzle end. The screw head is cylinder-shaped and passes into the gas block. It has depressions in it that allow a spring-loaded ball to hold it securely in place under recoil. The very top of the screw head has holes where a bullet nose or paper clip can pass through to make adjustments. It is a simple and rugged design.
A small but thorough design improvement that Savage made involves the gas key that sits atop the bolt carrier. Most direct-impingement rifles have the standard key that dovetails into the carrier with two large screws holding it in place. Those screws have to be staked well or they will loosen and allow gas to leak over time, which causes malfunctions.
The MSR 10 gas key is integral to the carrier so it can never leak. Savage accounted for wear on the portion of the key that slips over the gas tube where it enters the upper receiver. The gas key can wear at this spot over time, develop a knife edge and leak. This also causes malfunctions, so the gas key occasionally needs to be replaced.
Savage has a short tube at the end of their gas key that is held in place with a roll pin. Should the gas key start to wear, push out the roll pin and install in a new tube to make it as good as it the day it left the factory.
The Long Range also has a stubby, nonreciprocating, side-charging handle that's perfect for this rifle. It allows the shooter to comfortably cycle the rifle while in the prone without disturbing one's shooting position.
Accuracy testing of the MSR 10 went even better than we expected with the Long Range. It provided nothing short of a luxurious shooting experience. The lightened bolt carrier group and buffer, when combined with the adjustable gas block, extra-long gas system, and outstanding trigger made shooting accurately as effortless as possible. The rifle has so little recoil, it's hard to believe this is a long-range rifle capable of shooting consistently out to 1,200 yards when chambered in 6.5 Creedmoor.
The Long Range comes with Blackhawk's Blaze two-stage trigger. While we were not impressed with the Blackhawk Blaze trigger installed in the Long Range's little brothers - the MSR 15 Patrol and Recon - the two-stage variant in this rifle performed very well. We are trigger snobs and would not replace this one. It's good.
The rifle proved capable of excellent accuracy. Group sizes are all five shots at 100 yards. The MSR 10 is definitely a sub-MOA rifle.
We didn't think Savage would be able to outdo themselves after the MSR 15s we tested in 2017. Those were a lot of rifles for the money. Still, the MSR 10 Long Range is better. It has features found on rifles costing a $1,000 more and wraps them in a package so user-friendly it has to be experienced. Our advice on chambering? We suggest 6.5 Creedmoor.
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