Test: Mauser M18 Fenris in 6.5 Creedmoor, the heavier hunting rifle option

The Fenris has a 22-mm diameter, cold hammer-forged barrel which is screwcut 18x1 for a moderator or muzzle brake. The barrel shows deep blue/black finish that contrasts the matt black finished steel action. It’s parallel in profile until meeting the action where the reinforce swells out, completing 24”/610 mm overall length. Mauser’s M18 action uses a three-lug, push feed bolt with twin plunger ejectors that automatically throw spent cases free with great vigour after the single extractor claw recessed into the right lower lug draws cases from the chamber. There is a single raceway cut into the bolt which runs along the bolt’s anti-rotation pin that also acts as the bolt stop. A serrated bolt release catch is on the left side of the rear action bridge. 

Mauser M18 Fenris: the action

This three-lug bolt requires 60-degree lift to open and cock the action. Overall travel is 113 mm on this single length action available from .223 up to .300 Win.Mag. The bolt handle projects 90-degrees straight out, it’s 75 mm overall length is capped with a 19-mm diameter teardrop handle for secure grip and fast operation of an action that’s hard to jam even deliberately. 

Mauser M18 Fenris in 6.5 Creedmoor: we tested it.

This 6.5 Creedmoor rifle has a ten round polymer magazine plus one in the chamber if desired (magnum chamberings are 4+1). It’s a twin column unit so can be loaded quickly with minimal effort; cartridges simply clip into the top and this can be done with the mag in or out of the gun. It’s also worth noting that in the Creedmoor, single rounds dropped through the ejection port onto the polymer follower will feed directly into the chamber as the bolt closes. There is a recessed release catch in front of the magazine and a three-position safety catch completes the action’s controls. This is forward for fire; middle is safe with bolt operation and rearmost also locks the bolt. It’s silent in operation when rolled carefully under the thumb. Trigger pull is adjustable from 1,000-2,000 g using an Allen key, there is 2 mm of overtravel measured at the blade’s tip after break and this rifle had an average breaking weight of 41 oz/1,163g.

The stock features an aluminium bedding block to retain the action and recoil forces without any bedding stresses apparent.

The action is fastened into the GRS stock with two 5-mm Allen headed nuts either side of the magazine well which is part of the stock’s injection moulding, the bottom metal is a separate aluminium trigger guard which is internally bolted to the stock. The underside nuts have sprung washers to remain locked in position and screw onto the M6 studs that are attached to the underside of the cylindrical action. There is an aluminium bedding block within the polymer stock that interlocks with the recoil lug and action for a stress-free fit between both key components. Scope mounting is straightforward with a 20 MOA (Minutes Of Angle) inclination Picatinny rail screwed to the action in four places enabling greater long range dialling capability.

Mauser M18 Fenris: the stock

GRS’s Fenris stock is an asymmetric delight with masses of grip from the honeycomb like chequering pattern with stock adjustability for a great fit.

GRS’s Fenris stock is an asymmetric design whose mid-green colour contrasts nicely with the black of the rifle. The forend is stiff and allows the barrel to fully free float in all scenarios without any intermittent barrel contact affecting harmonics or zero. The beavertail forend is 57-mm wide to offer plenty of hand filling grip without excessive need for force. The grip and forend use a honeycomb-like pattern instead of checkering or stippling. This is a nice style as it’s got real visual character with assured grip in all conditions with no muscle effort.

The characteristic long straight bolt handle has 60-degree lift and is easy to access quickly with plentiful leverage for fast reloads.

From the action rearward, the Fenris stock becomes asymmetric with a right-hand angled grip that’s very comfortable in prone and well supported positions. Sadly, you can’t have a left hander and although possible, it’s not particularly comfortable to shoot left-handed in anything but a backup scenario. 

The honeycomb texture swells into your palm on the lower right section of the grip and reach to the trigger blade from the throat is 80 mm which for my medium/large hands, is incredibly comfortable with immediate index finger pad contact on the trigger blade. 

There are also finger grooves on the grip’s front surface.

Quick release anchor points for a biathlon style carry are fitted front and rear of the stock

The adjustable cheekpiece has 25 mm of vertical travel, it’s also asymmetric suited to the right-handed shooter, fitting under your cheekbone without undue jaw displacement. Height adjustment is controlled in detented stages with a sprung button on the right side of the stock with similar controls for length of pull adjustment from 343-375 mm. All the mechanics are rigid without any rattles in position with a medium/soft LimbSaver recoil pad that’s 23 mm thick. 

This moulds precisely to your shoulder pocket without feeling spongey, it’s 44-mm wide and 132-mm tall so spreads the recoil loads evenly which will be appreciated in the larger calibres like .30-06 and .300 Win, a Creedmoor is very gentle in comparison. Recoil transit is linear with very little point of aim disturbance and similarly, the weight and balance of the gun allows effective bolt operation without point of aim disturbance, and you can easily keep your head in position without any bolt interaction towards your nose (and I have a big nose).

Test firing the Mauser M18 Fenris 

The Fenris stayed sub MOA with all ammunition tested. I found the 93-gr RWS Evolution Green superb for foxes with flattest trajectory to 300 m.

I used a broad selection of ammunition using bullet weights between 93 and 156 grains to trial the versatility of the long, heavy barrel with 1 in 8” twist rate. All the ammunition used beat the common MOA standard for three rounds, here it did it with five rounds which is an added benefit. I found the heavy barrel was temperature stable and although groups opened slightly when it got very hot (20 rounds), this is not at all unusual for any barrel after long continuous fire. 

There was no mean point of impact/zero shift. Magazine feed and ejection were totally reliable, and I found the trigger consistent for weight and delightfully positioned for the best tactile operation. Its curved blade allowed my index finger to consistently fit in position every shot and because very little grip tension is needed for a secure hold, you could totally concentrate on trigger pressure with such a relaxed, yet well supported firing hand.

Bullet Weight/gr
Stated Velocity on Box /fps
Average Velocity Recorded /fps
Muzzle Energy ft-lb
100 m 5-Shot Group mm/inches
RWS Evo Green
Hornady V-max
Hornady Outfitter GMX
Norma Match
Hornady TAP GMX
RWS Speed Tip Professional
Norma ORYX
The butt hook allows you to keep the gun locked into your shoulder and with solid underside support from your hand or a rear bag.

I have used quite a few laminated GRS stocks in the past and am familiar with the inherent geometry, yet I feel the Fenris seems more comfortable due to the tactile grip and recoil dampening character of a well-structured polymer compared to laminated birch. It is rotationally stiff so any torque you apply to it is transferred directly to the supporting rest without any perceptible twist or instability in the forend and I am also pleased to report the forend resists compression when clamped in a shooting tripod’s jaws, also without any point of impact changes. The butt hook enables good grip of the stock into your shoulder which is helpful because the bolt appreciates forward pressure as you close the handle and a gun without a butt hook would easily push out of your shoulder if unrestrained. The barrel’s length and weight maintain good velocity appropriate for maximising long-range potential, as does the inclined Picatinny rail. The barrel’s ultra stiff at 22-mm diameter and has the mass to evenly distribute the heat generated by multiple shots, it took about 50 rounds through the bore to become fully run in and has since been consistent and easy to clean. Borescope inspection illustrates smooth steel consistency and when cleaning, the wrapped solvent-soaked patches never illustrate any tight spots or inconsistent friction through its transit. 

Mauser M18 Fenris: conclusion

The rifle is most comfortable shot from a bipod where its long-range capability is most apparent.

Mauser’s M18 action has already proven itself to me in previous chassis and sporting stocked formats. Seeing it fitted with a heavy barrel in the Fenris stock with an inclined Picatinny rail for long range use illustrates the versatility of the foundation action and its inherently capable twin column magazine system. Mauser make great sporting rifles so it’s great to see them adding to the portfolio with what I feel is ergonomically the ultimate GRS stock which I have found superb in use, so much tactile assurance from the honeycomb grip sections without any need for undue effort regardless of atmospheric conditions. I like the fact Mauser have focussed their design ethos correctly and delivered what they promise because although not a hunting rifle for everyman, this is perhaps a larger, heavier option for those who do like to hunt with a bigger heavier rifle although I don’t personally want to carry it for long distances and I also feel the more conventional sporters like the M18 Stainless offer faster handling in more dynamic situations.

Mauser M18 Fenris specs and price

6.5 Creedmoor (test rifle), .223 Rem., .243 Win., .270 Win., 6,5x55 SE, 6.5 PRC, .308 Win., .30-06 Spring., 7x57, 8x57 IS, 7mm Rem. Mag., .300 Win. Mag.
Magazine Capacity:  
10+1, Magnum 4+1 

Barrel Length:

24”/610 mm, 22-mm diameter, threaded 18x1

Length of Pull:
13.5”-14.75” (343-373 mm)
Single stage, adjustable from 1,000-2,000 g
GRS stock made of fiberglass reinforced high tech polymer
Overall Length: 
1110 mm/43.25”
Total Weight:

9 lb 12.4 oz/4,435 g

Price (in U.K.):



Ammunition used:

Hornady, www.edgarbrothers.com

RWS/Norma, www.ruag.co.uk

Also used:

Minox 5-25x56 Long Range Riflescope, www.blaser-group.com

Tier One Scope rings, www.tier-one.eu

PARD DS 35-70 and BOG Death Grip Tripod, www.sportsmanguncentre.co.uk

Wildcat Evolution Sound Moderator, www.wildcatmoderators.co.uk

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