Browning’s X-Bolt Mountain Pro Tungsten

Not a mango amongst the pears.

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03/27/2022 – Lately, I have been doing a good deal of “order and pick up” grocery shopping. It is not that I am lazy, as much I would rather keep a young person in a job, than have them unemployed and drifting off into the world of political activism and attempting to mold the world into their own image. Which is how Maine legislated a $15/hour minimum wage and McDonald’s statewide price for a Quarter Pounder with cheese is $137.36.

So I got home and began to put groceries away, when I discovered my order for three Bartlett pears, was filled with two pears and a mango. An accident filling the order? I doubt it. Who in the world could mistake a mango for a pear? No, I think this is part of a bigger federal government overreach, or Joe Biden’s plan to mitigate supply chain problems; satisfy pear shortages by substituting one mango in place of a third pear requirement. But what about mango shortages? Are you kidding? No one eats those things!

Is there a point in all of this? You bet. The reason someone attempted to sneak a mango into a pear delivery is because they know that society has grown numb to details. If the difference is not obvious in a picture, it just does not exist. No time to examine further, AKA “I’m late, I’m late! For a very important date! No time to say ‘hello, goodbye,’ I’m late, I’m late, I’m late!”.

Unfortunately, a good number of firearm manufacturers have tapped into the mango – pear phenomena. They make products that look similar to competitors on the outside, lack most of the substantial qualities on the inside, and hope this deficiency slips by… insulated consumers.

Details that define the X-Bolt Mountain Pro Tungsten Browning

Browning achieves mechanical accuracy using techniques that were once reserved for expensive custom firearms. The action is glass bedded at both ends, the recoil lug receives the same and the barrel is allow to free float. The result is the barrel returning to the same position after each shot with less exposure to non-uniform pressures.

Browning also took into consideration the shooter at the back end of a 6 pound, 300 mag, by installing a Browning Recoil Hawg muzzle brake. The Hawg reduces felt recoil by up to 76%, rendering the Mountain Pro a soft shooting rifle. Yes, muzzle blast is increased and some folks my not want that tradeoff. For them, the brake can be removed and a thread protector screwed on in its place. The third option regarding muzzle devices would be to remove the brake, install a silencer…. suppressor as referenced in the manual, and get recoil and report suppression.

Recoil pads are often taken for granted, which is unfortunate, because at times a rifle thought to be an unpleasantly hard kicker, just has a… what’s the word I am looking for here? Oh yeah, “crappy”, a crappy recoil pad.

The Browning Inflex recoil pad is a good one, as it is recoil absorbing and it directs the stock’s comb downward and away from the shooter’s face. So for those who do not want the trials and tribulation of a brake or a silencer, Browning has taken felt recoil down to a moderate level.

rowning X-Bolt Mountain Pro Tungsten
Manufacturer Miroku, Japan
Item # 035540246
Type Bolt Action Tri-Lug 60º Lift
Caliber 300 WSM
Mag Capacity 3
Barrel 23″ Stainless Steel – Cerakote
Receiver
Stainless Steel – Cerakote
Rifling 1:10″
Weight 6 Lbs 1 Oz
Overall Length 43″
Stock  Carbon Fiber
Length of Pull 13 5/8″
Drop at comb 11/16″
Drop at heel 1/2″
Sights Clean
Scope Mount
X-Lock
Trigger Feather Trigger – Adjustable
Safety Tang
MSRP $2,499.99

Browning’s Feather Trigger is an advancement over a conventional two lever trigger in a number of ways. The addition of an interim trigger sear connecting the trigger to main sear adds mechanical advantage, which reduces effort required to release the main sear. The trigger is in constant contact with the trigger sear, so take up is essentially non existent.

The sear release is vertical, which results in a clean release of the rifle’s firing pin, reduced lock time and consistent primer strikes. Internal contact parts are polished and hard chrome finished, which reduces friction and pull effort and eliminates creep. The Feather Trigger is preset at the factory for a 3.5 lb pull, but is pull adjustable between 3 and 5 pounds.

While a rotary type by design, the polymer magazine centers ti top round for optimal feed alignment. The magazine holds the ammo and provides a flush stock bottom. Latching is positive. There is room in the magazine for the handloader to have more leeway in setting cartridge overall length. In this case, where max length spec for the 300 WSM is 2.860″, some ELD bullets were loaded to 2.920″ and cleared the magazine and fed without a problem.

The X-Bolt tang safety blocks both the trigger sear and the firing pin when engaged. The unlock button at the root of the bolt handle allows the bolt to be opened with the safety fully engaged. In this case, the rifle is not cocked, so the tang safety cannot be engaged and the unlock button is flush with the bolt handle and cannot be depressed.

The bolt body and bolt handle are fluted, the former to prevent gunk from accumulating and impeding bolt movement, the latter to provide a nonslip surface. The three locking lug indexing results in a 60° lift. The recessed bolt face provides improved case head support and better gas management in the event of a case head fracture or popped primer. Cerakote provides a substantial layer of protection.

Last, but not lease, the Browning X-Lock feature secures scope mount bases at four corners rather than just two aligned with bore centerline. For lightweight scopes, this may not be a a huge benefit. However, when large, heavy optics and lightweight magnums are combined, the enhanced mount strength increases structural reliability.

The 300 WSM

Introduced in 2000, 22 years old. For some reason, it still has that new cartridge smell.

The original factory load for the 300 WSM pushed a 150 grain bullet to a muzzle velocity of 3,200 fps and a 180 grain to 2,970 fps. By comparison, the short action 308 Winchester which shares a common case length and cartridge length, has a muzzle velocity of 2,820 fps for the 150 grain and 2,620 fps for the 180 grain.

Moving to a long action 300 Winchester Magnum, 150 grain velocity is 3,290 fps, 180 grain velocity is 2,960 fps. By comparison, the 30-06 Springfield 150 grain standard is 2,920 fps MV and 2,700 fps MV for the 180 grain bullet. And, yes, factory loads these days are all over the place with some of the specialty 30-06 Springfield loads approaching magnum cartridge velocity.

So does that render the 300 WSM performance edge moot… like a cow with a Dutch accent? Not at all. The 300 WSM delivers its performance from a short action rifle, requires a relatively shorter barrel to attain spec performance, and that performance is delivered across all brands rather than a limited selection. At this time, there are forty factory loads for the 300 WSM.

What about handloads?

There is a listing of 300 WSM loads in the Real Guns handload section, however, the following additional loads were assembled for the subject rifle. Four typical hunting bullets were selected, two lead core, two monolith copper alloy.

Bullet Type Construction Weight
Grains
Length COL
Winchester Power Point Jacked Soft Point Jacketed Lead Core 150 1.050 2.840
Barnes TTSX Poly Tip Boat Tail Solid Copper 168 1.415 2.850
Barnes TTSX Poly Tip Boat Tail Solid Copper 180 1.480 2.860
Hornady ELDX Poly Tip Boat Tail Jacketed Lead Core 212 1.570 2.920

Nothing in particular to note, other than none are compressed loads. Cannelure position was ignored. Once fired cases were full length resized with the die expander ball removed to increase neck tension on bullets.

Handload Data

Warning: Bullet selections are specific, and loads are not valid with substitutions of different bullets of the same weight. Variations in bullet length will alter net case capacity,  pressure and velocity. Primer selection is specific and primer types are not interchangeable. These are maximum loads in my firearms and may be excessive in others. All loads should be reduced by 5% as a starting point for development where cartridges have greater than 40 grains in capacity and 10% for cartridges with less than 40 grain capacity following safe handloading practices as represented in established mainstream reloading manuals. Presentation of these loads does not constitute a solicitation for their use, nor a recommendation.

300 Winchester Short MagnumSI
Firearm Browning X Bolt
Barrel Length 23″
Max Case Length 2.100″ +0.000″/-0.020″
Min – Max COL 2.560″ – 2.860″
Primer CCI 250
Bullet Diameter 0.308″ +0.000″/-0.0020″
Reloading Dies Redding F/L

Bullet Type Bullet
Weight

Grains
Net H2O
Grains
Capacity
COL” Powder Type Powder
Charge

Grains
Muzzle
Velocity

fps
Muzzle
Energy

ft/lbs
3 Shot
100 Yard
Group”
Winchester Power Point
150
 74.9  2.840 Reloder 16
69.0
3293
 3613 0.8
 Winchester Power Point
 150  74.9  2.840 Superformance
74.0
3203
3418
1.1
Barnes TTSX #30878
168 68.9 2.850 Reloder 17 68.0 3261 3968 0.9
Barnes TTSX #30878 168 68.9 2.850 RS Hunter
70.5 3189 3795 1.0
Barnes TTSX #30879 180
68.1
2.860
Reloder 17 66.0 3047 3712 1.2
Barnes TTSX #30879 180 68.1 2.860 Superformance 69.5 3112 3872 0.9
Hornady ELD X 212 67.8 *2.920 Reloder 17 60.5 2862 3857 0.6
Hornady ELD X 212 67.8 *2.920 Superformance 66.0 2790 3665 0.8
* Exceeds SAAMI OAL Spec

Is this good news? Even the 212 grain very low drag load is flat shooting for its weight. With only a 4.5″ max rise above line of sight, it has a 302 yard point blank range and a hold over that is reasonable out to 500 yards.

Best Zero Results 212 Grain Hornady ELD-X
Near-Zero – Yards. 22 Mid Range – Yards. 159
Far-Zero – Yards. 291 Max Ordinate – Inches +4.5
Point Blank – Yards 302
Yards 0 50 100 150 200 250 300 350 400 450 500
Velocity – fps 2862 2791 2722 2654 2586 2520 2455 2390 2327 2265 2204
Energy – ft.-lbs. 3855 3668 3487 3314 3148 2989 2836 2689 2549 2414 2285
Momentum – lbs-sec 87 85 82 80 78 76 74 72 70 69 67
Path – in. -1.50 1.63 3.64 4.48 4.08 2.38 -0.68 -5.18 -11.21 -18.84 -28.17

Three shot groups? I know. If you find yourself shooting 5 shot groups to determine probable field performance, more range time may be in order. It is pointless to shoot 5 shot groups if the rifle will never see that many consecutive rounds in its intended applications.

The Browning’s barrel is thin, 0.615″ at the muzzle and fluted. Not ideal for sustained, long range fire as might exist in a competitive shooting environment, but it is a heck of a configuration for a lightweight hunting rifle.

The stock felt really good. It’s not a fatty, but it is hand filling and balanced. The geometry is excellent, the gripping surfaces are properly placed for field shooting positions. The high comb centers line of sight through the center of a 30mm scope tube.

The X-Bolt Mountain Pro Tungsten is an easy shooter from a recoil standpoint, but a little loud from a report standpoint. After trying it out; a silencer does wonders softening recoil and dampening sound. Yes, it does make the Mountain Pro Tungsten significantly longer than Browning intended. Your choice of compromise; brake, no brake, silencer.

The X-Bolt Mountain Pro Tungsten is what Browning customers have come to expect, a very nice rifle with no trace of mango.

But what about the much maligned mango? It just needed a little more substance to bring out its value. In this case, a little low carb, low calorie vanilla ice cream.

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