Hasler’s Bull
The Hasler Ariete bullet stands among the best monolithic hunting bullets on the market. In terms of accuracy it has almost no competitor, and its effect on target ranks among the top. This time we received for testing another Hasler bullet bearing the name Bull. How does it compare to its successful sibling?
Introductory photo: Hasler Bull bullet.
The Italian firm Hasler, which specialises in the manufacture of monolithic bullets for reloading, we have already presented on the pages of our magazine in connection with the top‑of‑the‑line and to a large extent universal Ariete bullet. In the company’s offering you will however also find somewhat more specialised hunting bullets, in particular the “Hunting” model, which deforms more readily and is therefore suited for hunting small/varmint game, and conversely the tougher Bull bullet, intended for hunting harder game. In this article we will focus precisely on the Bull. Before we delve into it, it is appropriate for completeness to mention that since our last article the company has begun producing factory cartridges loaded with the Ariete and Hunting bullets, but for the moment nobody imports them to us and the Bull bullets which we are discussing remain offered only as separate components — so at least for now it is a matter exclusively for hand‑loaders.
„A system of ribs reduces bullet drag while travelling down the barrel, resulting in slightly calmer behaviour at the shot, higher velocity and less stress and heating of the barrel and thus reduced wear!“
Construction
The Hasler Bull bullet, just like the Ariete, is produced by machining from a bar of special copper alloy. Thanks to the manufacturing method the result is extraordinarily consistent, which corresponds not only to perfectly machined surfaces, but also to a negligible weight deviation across individual bullets, which I can confirm from my own measurements. The ogival geometry, noticeably less “pointed” compared to Ariete, is, according to the manufacturer, better balanced between terminal effects in the target and external ballistic properties. In short, it’s a kind of compromise between sharp “spitzer” points and the classical rounded tip. The ballistic coefficient is however still decent. For example, the .308/167 gr variant has a BC of 0.51. The bullet’s base is slightly bevelled; in the front portion we find an expansion cavity covered by a durable polymer aerodynamic tip made of green polymer. Just as with Ariete, on the surface we find a system of ribs which protrude from the bullet body by less than a tenth of a millimetre. It is precisely into these that the rifling grooves cut. This solution reduces drag of the bullet while travelling the barrel, resulting in a slightly calmer behaviour at the shot, higher velocity and lower stress and heating of the barrel, and thus lower wear, compared to a conventionally designed bullet of the same parameters. Moreover, thanks to this feature the Hasler bullets can be satisfactorily stabilised even in slower twist rates.
Unfortunately the bullet range is limited to only five options in two calibres. Specifically (calibre/weight): .284/125, 139 gr; .308/159, 167, 180 gr. Compared to the Ariete with 23 variants in 9 calibres this is a marked difference. I tested the .308/167 gr variant, in cartridges .308 Win and .300 Blackout.
Advantages / Disadvantages
+ top-tier accuracy
+ excellent for tough trophy game
+ non-fragmenting
- high price
- narrower range of use
Example of limited deformation at impact velocity around 520 m/s.
At the range
With the Ariete bullet I achieved a group just under 0.5 MOA, so I went to the range with the Bull with high expectations. And I was not disappointed! I managed to achieve a 0.7 MOA group (firing at 150 m, average from two 6‑shot groups, excluding the worst hit, measured center‑to‑center). As usual, I tried several seating depth and powder charge combinations. The best results from a 457 mm barrel with a 1:10” twist rate were achieved with 38.5 gr of powder D037‑04 and OAL 69 mm (jump 2.3 mm), with a measured and averaged muzzle velocity of 751 m/s. I must point out that among the tested combinations, the differences in target results were not dramatic. The worst group hovered around 1.2 MOA. Tests with .300 BLK yielded poorer accuracy, just under 2 MOA — though this was with a semi‑automatic firearm and only a 254 mm barrel — but again the difference between the best and worst configurations was minimal, with the twist rate this time being 1:7”. From this I cautiously conclude that the Bull belongs among tolerant projectiles that do not require finicky tuning. However, all Hasler bullets, Bull included, are subject to several key rules that must be followed — see the box “reloading tips”.
Accuracy was satisfactory even in the case of “slow” .300 BLK rounds with fast twist. Their velocity, however, is insufficient for proper bullet expansion.
Example group at 150 meters.
The manufacturer states that the Bull can achieve exceptional expansion — from an initial 7.62 mm up to almost 25 mm without fragmenting. Based on my good experience with Hasler, I believe this is possible, but based on testing I am convinced that this depends on high impact velocity and dense tissue. Unfortunately, neither the manufacturer nor other sources define the exact velocity threshold, but it will certainly be higher than the usual minimum of 500 m/s. At that speed the bullet’s front deforms, but the diameter increases only slightly, as you can see in one of the photos. At higher velocities it proved nearly impossible to capture the bullet. I use a tried‑and‑true test setup with a layer of leather, followed by 50 cm of modeling clay and a paper catch layer, but the Bull bullet, at over 600 m/s, passed through all layers like butter and disappeared somewhere into the range backstop.
Reloading tips
The ribbing presents several challenges in reloading. First of all, all Hasler bullets perform better with sufficient jump — the distance between the bullet’s bearing surface and the rifling. The manufacturer recommends a minimum of 1 mm. Due to the ribs, this is hard to measure precisely, so I suggest taking the standard max SAAMI OAL and subtracting 2 mm, then starting your load development from that point. The manufacturer also recommends using a slightly faster-burning powder than would normally be ideal per reloading software, since the bullet creates less bore resistance. Finally, there is a rule that for bullets with three rear ribs, at least two should be seated inside the neck of the brass case. The case neck must be properly resized, and light crimping to help hold the bullet in place is also beneficial.
All Hasler bullets perform better with a sufficient jump — the distance between the bullet and the rifling.
Hasler Bull is an ideal choice for hunting tough, trophy-class game.Hunting Use
Based on the condition of the bullet channel in the clay, I estimate the minimum impact velocity for reliable terminal effect starts around 600 m/s. I wouldn’t worry at all about a maximum. The Ariete, made from the same material known for its exceptional cohesion, did not fragment even at a measured impact velocity of around 830 m/s — and the Bull, based on the absence of fragments in the clay, performs similarly.
Therefore, the Bull is best suited for hunting heavier, tougher game. In our conditions that usually means trophy-class European red deer and mature wild boar. For hunters traveling abroad on guided hunts, its applications will be significantly broader. It is definitely not a “do-it-all” projectile — for small game/varmint, female or juvenile animals, and most medium game I would choose a different option. Unfortunately, this limited my practical testing to a single large wild boar, but the result was textbook. A shoulder shot to the vital area at just under 100 meters. Complete pass-through — no fragments or traces of them were found in the meat or under the hide. Entry wound damage was negligible, and the exit wound was about the size of a coin with irregular edges. Meat destruction was minimal, but vital organs showed significant damage. The animal dropped 10–20 meters from the point of impact. Of course, a single successful hunt is limited in its evidential value, but when viewed together with range test results and reports from other hunters who’ve used the Bull longer-term, you can get a fairly clear picture of what to expect. In short: a specialty bullet for tough game, especially in combination with high-velocity cartridges.
The manufacturing quality — truly top-tier — is, understandably, reflected in the high price. Depending on variant, the Bull will cost 37.2 to 39 CZK per round, with the tested one priced at 38.5 CZK (sold in boxes of 50).
Hasler bullets including the Bull variant are available for purchase at STROBL.CZ s.r.o. More information can be found at strobl.cz or on the manufacturer’s website: haslerbullets.com
Photo credit: Author’s archive
Author: Tomáš Ježek
Originally published in Lovec magazine by Extra Publishing