First Look: Savage B.Mag .17 Win. Super Mag Rifle
By the Guns and Shooting Online Staff
The B.Mag, chambered exclusively for the new .17 Winchester Super Mag (WSM) cartridge, is the first rifle introduced since ATK purchased Savage Arms. It is reported to have been in development for 18 months. We have seen quite a bit of incorrect information published about this rifle, apparently based on pre-production samples released to certain favored media outlets. The rifle reviewed here is the standard production version sold over the counter by Savage dealers at the time of this review. Our B.Mag rifle came with a 100 yard, three shot test group that measured 0.6" center to center.
Savage Arms (www.savagearms.com) and Winchester Ammunition (www.winchester.com) cooperated on the .17 Win. Super Mag project, with Winchester developing the cartridge and Savage developing the first rifle to shoot it. Winchester reports that practically every major rifle manufacturer has requested and received the specifications for chambering the new cartridge.
The B.Mag rifle is based on an entirely new bolt action designed and sized specifically for the .17 Win. Super Mag cartridge. The barreled action is supplied with a matte black finish. The round receiver measures 5.8" long and 0.95" wide. The B.Mag action is unusual in that it uses dual, opposed, rear locking lugs and cocks on closing. Savage claims the latter was done to give the shooter better cocking leverage against the strong firing pin spring required for reliable ignition.
Only the bolt's cast aluminum alloy rear shroud, cast steel handle and locking lugs (all at the rear of the bolt assembly) rotate when the bolt is locked or unlocked; the silver bolt body does not rotate. Unlike most rimfire rifles, the firing pin is round. The extractor is a small, sharp hook at the front of the recessed bolt face. A receiver mounted ejector kicks fired cases out to the right through the receiver's oval ejection port. A heavy spring is required to drive the firing pin forward with sufficient force to reliably crush the rim of the strong .17 WSM case, which means that plenty of force is required to compress the spring when the cock on closing bolt is locked.
We found it easy to inadvertently short stroke the action when closing the bolt. Once the bolt lugs (located in front of the bolt handle) reach the slot molded into the stock for the bolt handle, the bolt handle can be rotated downward with the action open. Cycle the action rapidly for best results, making sure to shove the bolt all the way forward before applying any downward pressure on the bolt handle.
The bolt handle and bolt knob are cast as one piece. This piece is kept in place around the rear of the bolt body by a small set screw and the bolt shroud. The bolt shroud is cast aluminum (not steel) and located immediately behind (pressed tight against) the bolt handle. It is fastened by a larger machine screw through its rear end. The shroud prevents the bolt handle from slipping rearward.
The bolt knob is an unusual tubular shape that tapers toward the rear. We found the shape of the bolt knob satisfactory when opening the bolt, but somewhat uncomfortable for closing. Aesthetically, this semi-cylindrical bolt knob is not particularly attractive. We would prefer a more conventional, flattened oval, bolt knob. A longer bolt handle would increase the shooter's mechanical leverage and make closing the bolt easier.
The B.Mag uses an adjustable, thread-in barrel headspacing system similar to Savage centerfire rifles. Unlike a Savage Centerfire rifle, however, there is no external locking collar. The barrel is held in place in the receiver by two set screws concealed by the stock. A wide groove is machined into the barrel where the barrel meets the receiver; this hides the unavoidable (small) gap between receiver and barrel inherent with this type of headspacing system and two more rings of similar width and depth are machined in front of the first groove to further disguise the system.
The light contour, tapered, sporter type barrel is button rifled and 22" in length with a radius (hunting) crown. It is free floated in the stock. We would have preferred a heavier contour barrel, since the .17 WSM is primarily a varmint cartridge. The breech end of the barrel is cone shaped, allowing the rim of a chambered cartridge to protrude slightly beyond the diameter of the chamber end of the barrel.
The excellent Savage AccuTrigger is user adjustable from about 2.5 to 6.0 pounds. The trigger housing is cast of some non-ferrous metal, although the trigger itself is steel. There is a rocker type bolt release at the left rear of the receiver. The two position, steel safety slider is located just behind and beneath the bolt shroud, which is cut away on its underside to allow thumb access to the safety. A red plastic dot appears when the safety is moved forward to the "fire" position.
The black, one-piece, pistol grip, synthetic stock is commendably slender and generally well shaped. It is said to be made of some sort of Nylon plastic. The fluted comb is straight with very little drop at heel. Instead of checkering, there are four-panel, molded-in gripping areas at that we found non-functional. The grip cap is plastic with an embossed Savage Indian head design. The black rubber butt pad assembly snaps into the butt stock; it is not secured with screws in the conventional manner. Instead, there is an unsightly square hole in the top rear of the butt that serves as a mortise into which fits a plastic catch that secures the butt pad in place. Steel sling swivel studs are provided.
This stock is very light and so flexible that the forend can easily be twisted or warped by hand to contact the barrel. We found the source of the flex in the stock was not the forend itself, but the very thin area of the stock where the action is bedded. It is like there is a hinge in the middle of the stock.
Flexible stocks are detrimental to accuracy. Any attempt to use a shooting sling on the B.MAG rifle will pull the forend against the barrel and change the point of impact down range.
To remove the barreled action from the stock, which is necessary to adjust the Accu-Trigger, you first remove the magazine. Then remove the one-piece plastic trigger guard / magazine well by putting the rifle muzzle down on a carpet or pad and using the tip of a screwdriver blade to press on an integral plastic catch (marked by a spot of yellow paint) at the forward end of the magazine well; the front of the magazine well will pop up. Pull the trigger guard outward to detach it from the stock. (To replace the trigger guard, insert the tab at its rear into the matching notch in the stock and press the front of the magazine well down until it clicks into place.)
Once the trigger guard housing is removed from the stock, you can remove the two machine screws that hold the stock to the barreled action with a 5/32" Allan wrench. This is a unique and clever design that is obviously intended to minimize manufacturing costs.
Cartridges are fed from a new, detachable, center feed, eight-round rotary magazine that clicks into place in the rifle's magazine well. The magazine release is a plastic latch integral with the front of the magazine. A small "mousetrap" type coil spring is mounted at the top of the metal magazine guide rails at the rear of the magazine well. This spring is partly compressed and bears against a small ramp molded into the magazine's metal rear panel when the magazine in inserted fully into the magazine well. It helps to start the magazine out of its well when the magazine release is pressed.
The magazine body, as well as the rifle's one-piece trigger guard and magazine well, are formed from the same synthetic material as the stock. The rear panel of the magazine is metal to resist wear from the magazine spring and guide rails. The magazine's red plastic rotary cartridge follower is powered by a central, coaxial coil spring that is "wound-up" as cartridges are loaded into the magazine. Two small screws in the rear of the magazine allow disassembly.
Aesthetically speaking, the B.Mag's lines are good, but the matte metal finish and synthetic stock are low-end features. The .17 WSM deserves a polished blue action and a walnut stock. A laminated stock, heavy barrel version for serious varmint shooters would also be nice.
The factory mounted scope bases on the B.Mag are of the cross-slot (Weaver) type. These bases are supplied, because the B.Mag receiver's mounting hole pattern does not match the scope bases use on other Savage rifles.
Mounting a scope and rings on the B.Mag should add about a pound to the rifle's weight, for a total empty weight of about 5 pounds 7 ounces. This is too light for steady holding from unsupported positions, so we suggest attaching a bipod to the front sling swivel stud. This ultra light rifle should be fired from a bipod, shooting sticks or other rest to take advantage of its intrinsic accuracy. A semi-heavy contour varmint barrel and a stiffer stock would certainly be advantageous.
The .17 Winchester Super Mag (WSM) cartridge for which the B.Mag is chambered comes from an unusual source. Winchester (Olin) used their .27" industrial blank case, which was designed to drive concrete nails. Reinforced with a stronger case head and body to operate at higher pressure (33,000 psi), necked-down to accept .172 caliber bullets and given a sharp shoulder, the .17 WSM was born.
The much ballyhooed .17 Winchester Super Mag is the fastest rimfire cartridge ever. It launches a 20 grain bullet (BC .185) at a muzzle velocity of 3000 fps with 400 ft. lbs. of muzzle energy. The 200 yard velocity is 2058 fps and the remaining energy 188 ft. lbs. Compared to the .17 HMR, bullet drop and wind drift are essentially halved.
Winchester Elite Varmint .17 WSM ammo is packaged in 50 round boxes similar to those used for centerfire handgun ammunition. It sells for less than half the per round price of .17 Hornet centerfire cartridges.
Very noticeable to anyone operating a B.Mag rifle for the first time is the excessive force needed to lock the bolt. Rotating the bolt handle down cocks the heavy firing pin spring and requires an unusual amount of effort. The B.Mag action is never going to be smooth or fast to cycle compared to Savage's conventional cock on opening bolt actions.
The B.Mag is a sleek looking rifle and its action is obviously stronger than previous Savage bolt action rimfires. It is economically priced and chambered for the highest velocity and flattest shooting rimfire cartridge ever offered. We found the B.Mag's best features to be its Accu-Trigger, very accurate headspacing, new action properly sized for the cartridge (rather than adopted from an existing action), rotary magazine and dual locking lug bolt. Its worst features include the excessive force required to close/lock the bolt, a flexible plastic stock, very light contour barrel and ultra light weight.
Note: A full shooting review of the Savage B.Mag rifle can be found on the Product Reviews page.
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