Browning BXR .308 Win - ammo test
PUBLISHED: 18:32 18 July 2019
Broadsword takes a detailed look at Browning’s new bullet - the BXR in .308 Win - and puts it though its paces to see how it performs in a field test
Browning have now entered the ammunition market with factory ammunition, made under licence by Winchester with Browning's specifications.
There are two main categories of bullet type within the centrefire bullet calibres: a rapid-expanding bullet called the BXR, which uses a nickel-washed bullet with flat-base construction and large matrix tip with extended width and length; and the BXC bullet, designed for a more controlled and deeper penetration on bigger species and uses an aluminium cap.
I was looking at the BXR version, which is more relevant here in Britain. Ballistically, the Browning data shows that the .308 Win 155gr load on test has a muzzle velocity of 2,820 fps for 2,737 ft/lbs energy, with a ballistic coefficient (BC) of 0.405 and sectional density of 0.233. Let's see!
The BXR enlarged tip is designed specifically to aid in two ballistic areas of concern to a shooter - trajectory down-range ballistics and terminal energy transfer. Accuracy is obviously the most important, but as the bullet is the only part of your rifle kit that actually hits the target, it is this that is the critical item.
The enlarged tip is made from a proprietary mix of both copper and polymer in a ratio of 85% copper and 15% polymer. This solves two problems to any bullet design: one of which is creating the best BC for the weight and length of bullet, and the other providing the correct amount of bullet expansion at the terminal velocity.
Keep the bullet's tip or meplat perfect, and the better the BC value, and hence the better retained down-range ballistics culminating in superior energy transfer and less drop and wind drift.
This matrix tip has a beige/bronze colour and is secured to the rest of the bullet via a uniform crimp, but some were a little loose and were set aside.
The matrix tip weighs 7.8gr and is 0.390" in length and 0.217" in width at its widest point. This equates on this .308 Win bullet to a surface area of 70% of the total width of a .308 Win bullet profile, when viewed from the top. A normal polymer ballistic-tip-type bullet has a typical width of 0.146", so 47% of the total width.
Also, the BXR tip is a lot longer/deeper and so, compared to a ballistic-tip-type, it has a 48% impact area compared to that of 22%; a semi-pointed bullet has less than 10% impact area to initiate the bullet expansion.
What this means is that the initial expansion of the bullet is started quicker and more uniformly, so the bullet's jacket starts to retreat and peel back, followed by the softer lead core to form the characteristic mushroom shape of a lead cored bullet. The tip is usually disintegrated or pushed within the front half of the bullet, expanding to twice its size to increase the surface area and thus wound channel to create large hydrostatic shock, and hence energy transfer. The rear section of the BXR remains intact to push the bullet forward and continue the penetration.
Designing a bullet that penetrates sufficiently into the vitals and then expands enough for lethality is always tricky, dependent on the species of game you are shooting. The BXR, as the name suggests, is for rapid expansion of the bullet and those thinner skinned game. The Browning BXC is a more controlled expansion from the same Browning stable, and will be tested next time.
The bullet has a nickel-washed finish and cannelure at 0.370" from its base. It weighs 155gr and has a variation of less than 0.25gr for 20 weighed bullets, but the average weight was actually 156.2gr. Using the uniformity OAL gauge, the length from base to ogive was 0.6860", with a variation of less than 1%.
The case is nickel-coated. It not only looks nice but is supposed to tarnish less and offer a smoother cycling through the magazine of your rifle. I use nickelled case to denote differing reloads, and these cases are good quality and only have a variation of the 160gr weight of 2.25gr. When you deburr the neck, it will expose the brass below, so make sure the edge is uniform and smooth for correct bullet release if using the case for reloading.
Powder capacity was measured at 48.2gr of a small semi-flattened grey powder.
The cases are head stamped with the calibre and Browning's buck head logo.
The .308 Win is a very versatile round and as such can be shot in rifles with varying lengths of barrel, with good results in accuracy and velocity. I used a Merkel K3 with 20.5" barrel, a Tikka LSA55 with 21" barrel, and a Sauer 100 with 20" barrel to determine velocities and energy figures.
Accuracy wise, I was surprised, I'm not sure why, by how accurate this factory load was. The Merkel at 100 yards shot consistent 1.0-1.25" three-shot groups for 2,648 fps and 2,414ft/lb. The Sauer 100 with its 20" barrel shot really high velocities of 2,756 fps and 2,615 ft/lbs for their 155gr weight. Accuracy was amazing at 0.75 to 0.95" at 100 yards.
The old Tikka LSA55, some 40 years their senior, shot sub-0.75" groups with a velocity of 2,723 fps and 2,552ft/lbs. I would trade the slight reduction in velocity from the Tikka despite its longer 21" barrel (obviously worn) due to the better accuracy offered.
I used the Tikka for the penetration tests as it was so accurate with those BXRs. For the penetration tests, I used my trusty ballistic wax, which is the stickiest, most horrible gloop you can imagine, but it consistently shows down-range performance of a bullet and wound channel. So, when compared to other bullets shot the same way, you can build up a good library of bullet performance to make a more informed choice for your own needs.
I set up the wax at 50 yards, the recommended distance for the size, and shot a target first to check the zero and then one for the wax. Behind the test tube is a catcher wax tube in the event that the entirety of the 9.5" wax tube is penetrated. When I went to look at the result, I separated the two tubes and there was the bullet. It had exited the first tube and was not able to penetrate the second.
Now the messy bit! Halving the wax tube reveals the wound channel which can be measured by filling with water and the result doubled to get a wound channel volume.
This BXR penetrated a total of 9.5", just. The bullet started to expand after 0.5", and then created a 1.5" wide wound channel at its widest point with tapered front and rear portions. A total of 74.5ml volume for the wound channel, and after 6.5" it was just a straight bullet path. So, maximum energy was dumped within that 6.5" with frontal core lead and jacket fragments radiating out from the centre axis consistently. The Matrix tip disintegrated.
The retrieved bullet had a retained weight of 96.2gr with an expanded width of 0.6415". That's over twice the width of the original .308 cal bullet in a very classic and uniform mushroom shape, and the inner lead core was very uniformly spread and had not slipped at all in the rear portion of the jacketed bullet.
On real game, the Merkel K3 accounted for a lovely muntjac with energy transfer resulting in an instant humane shot, without too much venison spoilage from a classic heart shot. The Tikka was taken on a sika deer stalk down in Dorset and accounted for an immature sika male. Again, it showed a one-shot kill and dropped the sika on the spot; again, good energy transfer and little venison spoilage.
Bullet Weight (gr) Actual weight (gr) OAL" Penetration Total (inch) Depth before expansion (inch) Wound channel (ml) Retained weight (gr) Maximum width (inch)
BXR 155 156.2 2.7795 9.5 0.5 74.5 96.2 0.6415
Results from the Tikka
Muzzle fps/ft/lbs 100yds 200yds 300yds 400yds 500yds
Velocity 2,723 2,495 2,278 2,072 1,877 1,684
Energy 2,552 2,073 1,728 1,430 1,173 944
Bullet Drop (inch)
100yd zero 0 -3.6 -13.9 -32.1 -60.7
200yd zero +1.8 0 -8.6 -24.9 -51.8
Wind drift" at 10mph 0.9 3.6 8.5 15.7 26.3
I am a big reloader and enjoy the process, but sometimes it's nice to just pick up a box of factory and go, or even have it in reserve in case you forget your reloads or are travelling abroad. I was pleasantly surprised, not only by the accuracy in the test rifles, but by the real life performance on game where good penetration and expansion meant one-shot humane kills. What more do you need?
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