Straight Pull Bolt Action from Savage: Impulse Mountain Hunter Reviewed

in Authors, Bolt-Action, Gun Reviews, Rifles, Riley Baxter

Updated: May 14, 2023 BY Riley Baxter

In 2022, Savage Arms caused quite a stir in the firearms community with the release of their Impulse line of rifles that are easily identified by their new straight pull bolt action. The straight-pull bolt action has been around for a long time but has been primarily underutilized by the most popular firearm manufacturers. Savage has developed a simple, modern mechanism that utilizes a plunger and six ball bearings which produce an incredibly strong lock-up able to withstand the extreme pressures generated by today’s magnum cartridges. In this review I put one of these new straight pull bolt action rifles, the Impulse Mountain Hunter chambered in 7mm PRC, through a series of tests. Does it flop, or fly?

A rifle sits on shooting bags at the gun range. — The Savage Impulse Mountain Hunter is a lightweight, straight pull bolt action rifle.

About the Impulse Mountain Hunter

The Impulse Mountain Hunter is a lightweight hunting rifle that features Savage’s Impulse action which is a straight pull bolt design on an aluminum receiver, AccuStock Technology, and a Savage designed, Proof Research barrel. These particular features quickly bring the value of this rifle up to the $2,437.00 MSRP that you would pay if you purchase it. The rifle that I have is chambered in the new 7mm PRC, but it is also offered in 6 other calibers ranging from 6.5 Creedmoor to 300 Win Mag. This price stays the same regardless of which caliber you purchase. The full list of calibers offered can be found under the specifications heading in this article.

The Impulse action is lightweight and strong, thanks to its mostly aluminum construction and heat-treated steel barrel extension. The 20 MOA Picatinny optic mount is machined into the receiver itself and is also of aluminum construction. The bolt release is located on the rear left side of the receiver and functions a little differently than what I’ve seen on other rifles. This bolt release must be slid forward for operation, not pressed inward like a button.

Another cool feature of the action/bolt is the ability to change the angle of the bolt handle to fit your preference as well as swap sides for left-handed or right-handed operation.

Inside the rifle's action. — The bore of my rifle is covered in brass from the many rounds I fired and the action is filmed with dust, but what I’m really showing here is the heat-treated steel barrel extension inside of the aluminum action that captures the ball bearings which lock the bolt into place.

The next important feature is the AccuStock that the action comes nestled in. This is not a cheap, plastic stock. Yes, it is polymer, but there is an aluminum bedding block hidden inside that fits perfectly to the action, squeezing every bit of accuracy potential out of the system. Because the aluminum bedding block extends internally down the forend, things are very stiff and a bipod can be mounted without causing verticle stringing of your groups down range. On top of being conducive for accuracy, the ergonomics of the AccuStock are great. These ergonomics can be customized to the shooter due to the AccuFit system which allows the length of pull to be changed with different inserts. Cheek height can also be adjusted in a similar manner.

a rifle stock lays on the ground, taken apart. — An example of a few different cheek pieces and butt pad extensions, allowing for ultimate customizability for fitment with the AccuFit system.

The third major component that distinguishes the Impulse Mountain Hunter from the competition is the Proof Research carbon fiber barrel that is used. Depending on the chambering of this rifle, this barrel varies from 22 to 24 inches in length and my 7mm PRC has a 22-inch barrel. The profile of this barrel is of Savage’s design, meant to be a happy medium between a Sendero and a lightweight hunting contour, creating a stiff and accurate system. The Proof Research barrel on this rifle costs around $900 if purchased as a blank. Nearly $1,000 of this rifle’s MSRP is tied up in this component alone, which I am ok with because of my good experience with these barrels.

The carbon fiber wrap keeps things stiff and lightweight while the single-point cut rifling and lead-lapped bore throw bullets downrange extremely accurately. I’ve used many carbon fiber barrels over the years and I’ve noted that some twill weave designs are porous and absorb water, causing the fibers to be raised up if subsequently left in a cold environment. This makes the barrel uncomfortable to touch and can’t be good for longevity. That said, I have never had this issue with my Proof Research barrels and they are one of my top picks for a carbon fiber barrel.

A carbon fiber barrel. — A Proof Research carbon fiber barrel is both functional and attractive.

All Impulse Mountain hunters come with a 5/8×24 TPI threaded muzzle and a radially drilled muzzle brake. This brake that comes standard is one of my least favorites and is well-known to be a pretty inefficient design in general. I think Savage missed the mark on this one feature. Because of this, I did most of my shooting of this rifle with a suppressor attached. Removing the brake and installing a suppressor, or another muzzle device is incredibly simple. With my lightweight suppressor, this system really shines. The suppressor I used is an AB Suppressor Raptor 8 with a 5″ reflex. The 22-inch barrel keeps things from being too long with this can attached, the 7 PRC suppressed nicely without too much recoil which made it a pleasant shooting experience.

The muzzle brake attaches via 5/8×24 TPI muzzle threads.

Operation of the Impulse Action

To beat a dead horse, the Impulse action is a straight pull bolt action. During operation, the bolt handle pivots forward and backward in order to cock the firing pin and operate an internal plunger. When the bolt is pulled rearward to eject a spent case, the bolt handle pivots, cocking the firing pin and pulling the internal plunger rearward. This movement of the plunger allows the six ball bearings near the bolt face to unlock from a groove in the action and move into the bolt itself.

Now, when the bolt is driven forward, it strips a cartridge out of the magazine. At the end of its travel, the bolt handle pivots forward, pushing the plunger forward as well. This plunger shoves the ball bearings outward radially, locking them into the groove in the action. When the cartridge is fired, the rearward pressure on the bolt further increases the strength of the lock-up between the bolt and action because of the interaction of the ball bearings with the groove in the action that they lay in.

When the firing pin is cocked, the bolt is locked into the closed position. There is a button on the back of the bolt shroud that allows the bolt to be unlocked if pressed. This feature keeps the bolt from falling open, either losing your bullets or coming out of battery and causing you a missed opportunity in the field.

the Impulse action in the open position. Notice the ball bearings that lock up when closed.

Impulse action with the bolt closed. — The impulse action when closed.

Accuracy

Typically, I use a variety of ammunition for my accuracy testing, but due to the new nature of this cartridge, I was only able to get Hornady ammunition for this review. In my testing, I shot both the 175 gr ELD-X Precision Hunter and 180 gr ELD Match. Since I shot this rifle suppressed for most of my testing, I chose to shoot this accuracy test suppressed as well as with the factory muzzle brake installed. In both configurations, I shot prone using a front and rear bag for support and the target distance was exactly 100 yards as ranged by a SIG Kilo 8K ABS rangefinder. The optic mounted on the rifle was a Vortex Razor HD LHT 4.5-22×50, keeping the rifle lightweight, but providing all of the features I desire for a long-range capable system.

The Hornady 175 gr ELD-X averaged 1.194 MOA between suppressed and unsuppressed 5-shot groups, with both being very similar in size and point of impact. However, the 180 gr ELD Match averaged 2.03 MOA between suppressed and unsuppressed 5-shot groups while the suppressed groups were consistently smaller than the unsuppressed groups using this ammo. With a suppressor, the 180 gr ELD repeatedly shot groups such as this one shown which measures 1.57 MOA.

Suppressed with the AB Suppressor Raptor 8 with 5″ reflex, I shot a 1.26 MOA (1.32″) 5-round group with the 175 gr ELD-X and a 1.57 MOA (1.65″) 5-round group with the 180 gr ELD-M ammunition. Both groups were shot at a distance of 100 yards.

Using the factory muzzle brake, I shot a 1.12 MOA (1.18″) 5-round group with the 175 gr ELD-X and a 2.49 MOA (2.61″) 5-round group with the 180 gr ELD-M ammunition. Both groups were shot at a distance of 100 yards.

This rifle was shot by Savage before it was sent to me for review, and I’m assured that they shot groups that were 1 MOA or better using a Lead Sled-type apparatus and the Hornady ELD-X ammo. I’m not too proud to admit that savage’s paid shooters printed a group downrange that shaves at least 0.13 MOA off of my best-pictured group.

Specifications

MSRP: $2,437.00
Action: Bolt
Ejection Port: Right
Barrel Color: Black Carbon Fiber
Barrel Finish: Matte
Barrel Length (in)/(cm): 22 / 55.880
Barrel Material: Carbon Fiber Wrapped Stainless
Caliber: 7mm PRC (also 6.5 PRC, 6.5 Creedmoor, .308 Winchester, 300 WSM, 300 Win. Mag, 28 Nosler)
Magazine Quantity: 1
Magazine Capacity: 2 (4 for non-magnum calibers and 3 for 300 Win. Mag)
Hand: Right
Length of Pull (in)/(cm): 12.75 – 13.75 / 32.385
Magazine: Detachable Box Magazine
Overall Length (in)/(cm): 44.75 / 113.665 (7 PRC only)
Rate of Twist (in): 1 in 8 (7 PRC only)
Receiver Color: Black
Receiver Finish: Matte
Receiver Material: Aluminum
Type: Centerfire
Stock Color: Grey
Stock Finish: Matte
Stock Material: Synthetic
Stock Type: Adj. LOP & Comb Height
Weight (lb)/(kg): 7.34 / 3.33

A suppressed rifle on shooting bags. — The Impulse Mountain hunter suppressed with an AB Suppressor Raptor 8 with 5″ reflex being shot at the range.

Final Thoughts

The Impulse action is very new, which gave me some apprehension going into this rifle review. Even still, after spending a ton of time behind my Impulse Mountain Hunter chambered in 7mm PRC, all of my worries are gone. This rifle is not a typical bolt action, so the user cannot expect it to operate like one. After getting used to the pivoting, straight back, and straight forward motion to work the bolt, I can work this action much faster than a traditional bolt action. The Impulse is one of few straight pull bolt action rifles that are available and is a great option for consumers.

A close up of the Impulse mountain rifle. — The off-hand side of the Impulse Mountain Hunter.

The components used in the Impulse Mountain hunter are top-tier; keeping the weight of the system low and the toughness high. With a Vortex Razor HD LHT 4.5-22×50 mounted up, the rifle comes in at 8 lbs, 11 oz while it’s 7.34 lbs bare. The AccuStock feels fantastic, being lightweight and stiff. It has rubber grip zones in useful locations on the grip and forend. The detachable magazine box fits flush with the bottom of the gun, feeds well, and locks securely in place and the Savage AccuTrigger breaks cleanly at 3 lbs, as measured with a Wheeler Trigger Pull Gauge.

Even though the accuracy test left a bit to be desired in my mind, 1 MOA is still no slouch with a lightweight hunting rifle and 5-round groups. At the least, this rifle was very consistent and these group sizes were repeatable. Due to the large difference in performance between just the ELD-M and ELD-X offerings in 7mm PRC, I imagine that as other factory ammunition options come out I could find other offerings that shoot even better. All of these things add up to produce a great, lightweight hunting rifle with a lightning-fast straight pull bolt design, chambered in a hard-hitting caliber.

learn more about the Impulse Mountain Hunter HERE.

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