.376 Steyr

History

The .376 Steyr was officially introduced in 1999, the result of a joint venture between Hornady Manufacturing, Steyr-Mannlicher and the design philosophies of Lt. Colonel Jeff Cooper. The .376 was developed specifically as an African game legal cartridge for the Steyr scout rifle. For a short time the .376 was also chambered in the Steyr Prohunter rifle but this combination has been discontinued.

The Scout rifle concept was the brainchild of Lt. Colonel John Dean “Jeff” Cooper (USA 1920-2006). Jeff Cooper served in Both WWII and Korea, later he formed the American Pistol Institute which, as his interest became equally involved in rifle and shotgun, was re-named the Gunsite Training Center. Cooper trained military, law enforcement and private citizens how to shoot. His interests were primarily centered around combat training however Cooper was also immensely interested in hunting rifles. Cooper’s expertise in the field of Combat arms training inevitably influenced his thoughts about hunting rifle design. To Cooper, the hunting rifle was considered a tool with very basic, clearly defined functions. Artistic creativity and game/application specific cartridges had no place in Cooper’s mind

In the early 1980’s Jeff Cooper published an article describing what he considered to be the ideal rifle which he called the “Scout rifle”. These ideas were partly influenced by earlier rifle designs and Cooper's own ideas. Some of the carbines that influenced Cooper included the Steyr-Mannlicher Schoenouer, various Mauser carbines and the Lee-Enfield Jungle carbine. Cooper was also highly inspired by Remington’s 1965 release of the M600 carbine in .350 Remington magnum. Cooper also spoke of the Sako Battue.

As for cartridges, the colonel had always been a fan of the .30-06 Springfield. But after the introduction of the U.S military replacement 7.62 NATO (.308 Winchester), Cooper was quick to see the advantages of this highly efficient cartridge and its ability to produce high velocities from a short carbine length barrel. The specifications for Cooper’s ultimate rifle included:

• Weight with Scope and sling of 3kg (6.6lb), up to a max weight of 3.5kg or 7.7lb, magazine unloaded.
• Rifle overall length of 1 meter (39”) or less.
• Magazine fed bolt action.
• A low power scope (2-3x), mounted forwards of the breech to keep the action clear and accessible, to keep vision unhindered and to alleviate recoil / scope eye relief related flinching.
• Auxiliary aperture sights.
• A sling to be used as a shooting aid.
• A standard short action chambering to ensure ammunition availability and maximize magazine capacity.

Calibers to be: .308 Winchester as the optimum Scout rifle cartridge, 7mm08 Remington for localities that prohibited the use of military cartridges and lastly the .243 Winchester for youths and recoil sensitive shooters.

Accuracy was to be 4” or less at 200 yards.

Cooper described the Scout essentially as a “general purpose” rifle able to cleanly kill game up to 200kg (440lb) out to the limit of the shooter’s ability, nominally 300 yards.

More than just a hunting tool, Cooper envisaged the Scout as a civilian weapon capable of defending good citizens against corrupt tyrannical governments and criminals. To Cooper, the Assault rifle was the principle specialist tool of the infantry soldier while his bolt action Scout could be classed as the general-purpose tool of the civilian.

During 1990 Jeff Cooper was introduced to Steyr-Mannlicher's head honchos, giving him the opportunity to discuss the possibility of designing a Steyr rifle to Cooper’s Scout specifications. Following this Steyr began design and prototype development which would last through until 1996. In 1997 Cooper’s long awaited and much anticipated Scout rifle became a reality. Using modern materials the Steyr-Mannlicher Scout (more simply known as the Steyr Scout) was a radically new rifle for the Austrian firm. The Scout featured a synthetic stock, used aluminum throughout the action and plastic where ever possible, an integral bipod was included as were the Auxiliary aperture sights and forward mounted scope. The Scout was sold as a package to ensure that the rifle was fully optimized.

Following the release of the .308 Win chambering, Steyr introduced both the planned 7mm08 Remington and .243 Winchester chamberings, introducing a .223 Remington chambering a little while later.

Although Cooper maintained that the Scout should be chambered for readily available standardized cartridges, Cooper himself became interested in a heavy game version of the Scout. To this end Cooper built a .350 Remington magnum Scout rifle on a Brno short action rifle. After shooting and successfully stopping a lion dead in its tracks at only a few paces, Cooper dubbed this rifle his Lion Scout. The Lion Scout was built some time before Cooper’s involvement with Steyr-Mannlicher and it is unlikely that Steyr would have adopted it, even if Cooper had recommended it due to poor market acceptance of the .350 Remington Magnum cartridge. Nevertheless, caliber restrictions in some African countries inspired both Cooper and Steyr towards the creation of a .375 caliber Scout. Once again, Cooper became closely involved in research and development, this time focusing on an appropriate cartridge for the new rifle. To Cooper's thinking, the .375 caliber would be specifically suited to heavy game. A short action .375 cartridge would be preferable but a medium or long action .375 cartridge would be acceptable if this was the only way to drive heavy .375 caliber bullets at adequate velocities. That said, Cooper feared that this would be a large departure from his original concept.

A compromise was reached when Steyr formed a joint collaboration with Hornady ammunition. Hornady developed a short fat unbelted case based on the 9.3x64 Brenneke shortened 4mm (100 thou). The new case was designed to operate at 58,000psi with a maximum average pressure of 62,000psi. The new cartridge was introduced in 1999; Cooper also suggested that the cartridge be named the .376 rather than a name featuring it’s true .375 designation in order to save confusion amongst hunters. Various names were proposed, Cooper favoring the .376 Dragoon however Hornady and Steyr settled on the .376 Steyr.

The .376 Steyr is very long for a short action cartridge and can only be housed in short action rifles with long (modified) magazines. Hornady seat their projectiles to a length of 3.085” (78.4mm) while the Steyr Scout rifle has a magazine length of 3.150” (80mm). Hornady factory ammunition was and continues to be loaded with the 225 and 270 grain Interlock spire point bullets (though it is hard to say how long the 225 grain load will remain in stock). Current factory specs list both loads at 2600fps from a 24” barrel. In the 19” Scout, velocities fall around 25fps per inch, resulting in true velocities of around 2475fps. Both loads were kept to the same velocity to ensure minimal shift in points of impact when using the rifle abroad on a wide range of game with one sight setting.

Since 1997, the Steyr Scout has developed a small following.
 

Performance

Where velocity is low in a medium bore, the window of performance can be somewhat narrow. Most medium bore bullets work exceptionally well down to impact velocities of 2200fps. Between 2200fps and 1800fps, shot placement becomes ever more important. Below 1800fps, bullet expansion can be very poor.

To increase this window of performance, the medium bore user can, where applicable, decrease bullet weight as a means to increase velocity. Loads of this type can be very useful for hunting medium game in bush / woods conditions, producing very fast killing.

A second method of enhancing performance is to employ a bullet that is somewhat light for caliber, but very tough. Loads of this type can prove useful on large bodied deer out to moderate ranges.

A third means to maximize performance is to use a medium to heavy weight bullet, but of conventional construction such as the Sierra Gameking or Speer BTSP. Driven slowly, a conventional bullet can produce deep penetration while shedding some weight as a means to render a wide internal wound on large thin skinned game. Used in this manner, the Steyr and kin can prove exceptionally effective.

Unfortunately, the Steyr has limitations when hunting truly heavy game. A tough medium weight (250 grain) bullet can prove to be the most effective killer on heavy game however the hunter should not expect fast killing. Unless the hunter takes deliberate CNS shots, kills may take longer than 1 minute (sometimes much longer), allowing heavy game to cover considerable ground before collapsing from blood loss.

The .376 case holds around 80 grains water while the .375 H&H holds around 90 grains water. When both are utilized in a 25” barrel, the Steyr is around 150fps slower than the H&H. From a 19” barrel, the Steyr can fall below the 25” barreled H&H by up to 300fps.

Compared to the .35 Whelen, the .35 Whelen AI and the .350 Remington Magnum and taking various brands of brass into consideration, the Steyr holds around 5 grains more water, a very minor difference. The .376 Steyr is comparable to the .375-06 and especially the .375-06 improved and although the Steyr holds can hold a few more grains within its case, a 24” barreled 375-06 will normally generate identical velocities.

Unfortunately, the power of this cartridge or comparisons to other cartridges are irrelevant. The greater issue is the Steyr Scout rifle; cursed with weak plastic in the same manner as other rifles from this manufacturer. The result is very poor accuracy potential along with various malfunctions. Light weight rifles can be very handy, but there are some rules to physics and engineering that cannot be broken. The materials used also affect the velocity potential of this cartridge.

A further problem occurred during the initial release of the .376 when Hornady unfortunately produced a large batch of poorly formed brass (very high wall run out). This brass was not dangerous in any way, however it was incapable of producing concentric ammunition.

The Scout rifle concept is certainly interesting. However, I believe that such rifles must be extremely robust if they are to fit the bill.
 

 

Factory ammunition

As previously stated, Hornady produce two loads for the .376 Steyr. Both the 225 and 270 grain Recoil Proof Interlock loads have an advertised velocity of 2600fps and yield between 2400 and 2475fps in the 19” Scout.

The 225 grain bullet is a fast killer when used on medium game at close to moderate ranges. Unfortunately, I do not know if this load will continue to remain in production. The current load features a recoil proof version of the original Interlock bullet, being much the same as the original but without exposed lead at its tip. Apart from this both are much the same. The 225 grain bullet is designed to impart energy within medium game as opposed the hunter being stuck with a heavier premium bullet which can cleave to its momentum, produce a narrow wound and allow medium game to cover great distances before finally succumbing to blood loss. The 270 grain Interlock is adequate for non-dangerous game weighing up to and around 320kg (700lb). Like the 225 grain load, the 270 bullet does its best work at close to moderate ranges. From a muzzle velocity of 2450fps performance begins to taper off after 90 yards or 2200fps. Between 90 and 300 yards (1800fps) shots should be kept well forwards as a means to ensure fast killing. Neither load is ideally suited for shooting past 300 yards.

 

Hand loading

At this time of writing (2017), Hornady still manufacture brass for the .376 Steyr. Varget (ADI 2208) or IMR 4064 burning rates are about as slow a burning rate as the hand loader can go without sacrificing velocity from a 19” barrel. Varget is extremely good with heavier 250 to 300 grain bullets and the .376 case will handle slightly compressed loads of up to 70 grains of this powder type. Slightly faster powders in the Benchmark to H4895 range produce optimum velocities with all bullet weights along with pressures in the 58 to 60,000psi range.

Working velocities for the 19” Scout include 2650 to 2700fps with 200 grain bullets, 2600fps with 225 grain bullets, 2550fps with 235 grain bullets, 2500fps with 250 grain bullets, 2450 for the 260 grain Nosler, 2400 to 2450fps with 270 grain bullets and 2300 to 2350fps for the heavy weight 300 grain bullets. The .376, like other medium bores develops on average 25fps per inch of barrel length within the barrel length parameters of 16 to 26”.

One of the main considerations when reloading for the .376 Steyr is that while the brass may be capable of fairly potent loads (up to above 100fps faster than listed here), accuracy can be poor. The velocities above are in keeping with the common accuracy sweet spots of the Steyr Scout rifle.

In the following paragraphs I will discuss a small number of useful bullet designs pertaining to the .376 Steyr. Those who wish to explore the .375 bullet options in more detail are advised to study my .375 H&H text which serves as the parent document for the .375” family. Please also take note that the following information should be taken into consideration for both the .375-08 and .375-06, all of which fall into this same general velocity category depending on the barrel length used and individual bore tolerances.

To begin with, those wanting a true light to medium game bullet, may wish to consider the 200 grain Sierra Flat point designed for the .375 Winchester. Which when loaded to 2650fps can make for a very useful bush / woods bullet. The Sierra may not penetrate game end to end, but its ability to produce high trauma at close ranges results in immediate anchoring of game. Fully utilizing the energy of this medium bore on targets offering very poor resistance from certain angles. From a muzzle velocity of 2650fps the Sierra breaks 2200fps (muzzle velocity of the .375 Win) at 100 yards. It then breaks 1800fps at around 200 yards. The Sierra can be used a little way further but generally speaking, this is a very good 200 yard load.

The 225 grain Hornady Interlock may now be obsolete but I will include the following notes for posterity. This bullet was very useful when used in bush to semi open country on wild Boar and deer. Loaded to velocities of around 2550 to 2600fps this bullet produced very fast kills with rear lung shots out to 150 yards and clean killing out to ranges of 200 to 250 yards, useful to a maximum range of around 300 yards or 1800fps.

The 235 grain Speer bullet works well, though its bonding can inhibit energy transfer depending on how it is used. When used on very lean game this bullet works best at impact velocities above 2400fps though wounding is vivid at 2200fps. Shot placement is critical at 1800fps. On larger bodied deer, where it meets plenty of resistance, the Speer is useful down to impact velocities of 1800fps. Some would accuse this projectile of being too soft as if it should be capable of slaying heavy game simply due to its bore diameter. Yet to say such a thing is to miss the point. This bullet was and is designed for medium game and can tackle fairly hefty body weights when driven at mild velocities which do not place excessive strain on its bonding.

The 235 grain Woodleigh protected point Weldcore is tougher than the Speer Hotcor and therefore can display narrower wounding when launched at slower velocities if it does not meet enough resistance. In the .376 Steyr this bullet does its best work when used on very large bodied deer and antelope at close to moderate ranges. At impact velocities above 2400fps the Woodleigh is an emphatic killer. Below 2200fps shot placement is the key to ensuring fast kills.

The Barnes 235 grain TSX projectile can prove to be very useful in the .376. I am personally inclined to use this (and like bullets from smaller manufacturers) as a means to increase velocity (for the sake of nervous trauma) without any sacrifice in penetration when hunting very large animals. Again, personally speaking, this is where I believe such a bullet design comes into its own, driven as fast as the rifle will accurately allow and used at close ranges to tackle large body weights of up to 450kg (990lb) and in some cases heavier.

Readers will see that thus far, I have listed bullets from those that are the softest (for light game) through to those that are very tough (for large and in some cases, somewhat heavy game). Of the heavier weight bullets, the hunter must take impact velocities and body weights into consideration. When driven slowly, a heavy bullet can afford to gradually lose weight (resulting in wide wounding) without losing its ability to penetrate. This can be very useful on game weighing between 300 and 500kg (660 to 1100lb). One bullet that can work very well, whether loaded in the .375-08 or .376 Steyr, is the 250 grain Sierra Gameking. Loaded to a muzzle velocity of 2500fps in the .376 Steyr, the extra tough 250 grain Gameking breaks 2200fps at around 130 yards and 1800fps at around 330 yards. In the .375-08 wildcat from a velocity of 2300fps the Gameking breaks 2200fps at around 70 yards and 1800fps at around 260 yards. These loads may not boast the spectacular and emphatic performance of a high magnum but can be put to great use on large bodied game at close to moderate ranges and from varying angles without bullet construction issues. The 250 grain Gameking is exceptionally well suited to this application.

The Speer 270 grain BTSP can also be put to good use in the .376 Steyr for hunting large bodied game weighing up to 450kg (1000lb). This bullet is softer than the Gameking, working very well at lower impact velocities. Loaded to 2400fps the Speer breaks 2200fps at around 100 yards and 1800fps at around 330 yards. This can be a very good bullet to work with provided it meets enough body resistance (at least 150kg / 330lb) to ensure full expansion across the velocity spectrum.

When it comes to truly dangerous game we need tough bullets. In the .376 Steyr, both the 250 grain Barnes TTSX and Hornady GMX bullets can prove useful for challenging body weights. Many Scout rifles simply will not shoot these bullets at high velocities and killing can be quite slow when tackling heavy game weights. But if used with due care towards shot placement (including follow up shots), they get the job done. On the other hand, neck or head shots will achieve a very quick result without so much reliance on impact velocities.
 

Closing comments

The .376 Steyr has some merit as a utility cartridge for those who work in locations such as Alaska where dangerous animals may be encountered. But alas, this rifle and cartridge never fully took flight. The 376 cartridge simply did not offer anything vastly new in comparison to the likes of the 9.3x62 or .35 Whelen which both launch relatively heavy bullets at similar velocities. As things stand, Ruger have in recent years cornered the survival rifle market with their own .308 caliber scout rifle. Ruger now also produce the very potent .375 Ruger which may not be a scout cartridge, but has taken the compact medium bore rifle market by storm.

 

Suggested loads: .376 Steyr					Barrel length: 19”
No	ID		Sectional Density	Ballistic Coefficient	Observed MV Fps	ME Ft-lb’s
1	FL	Hornady 270gr SP-RP	.274	.380	2425	3525
2	HL	235gr Speer, Barnes TSX, Woodleigh.	.239	.301	2550	3393
3	HL	250gr Sierra BTSP	.254	.375	2500	3469
4	HL	250gr TTSX / GMX*	.254	.424	2500	3469
5	HL	270 Speer BTSP	.274	.429	2425	3525

 

Suggested sight settings and bullet paths
1	Yards	100	206	241	275	300
	Bt. path	+3	0	-3	-7.2	-11
2	Yards	100	212	247	275	300
	Bt. path	+3	0	-3	-6.4	-10.1
3	Yards	100	213	248	275	300	325
	Bt. path	+3	0	-3	-6.1	-9.5	-13.6
4	Yards	100	216	252	275	300
	Bt. path	+3	0	-3	-5.5	-8.8
5	Yards	100	209	244	275	300	325
	Bt. path	+3	0	-3	-6.6	-10.1	-14.3

Sight height 1.6” (Scope).
 

No	At yards	10mphXwind	Velocity	Ft-lb’s
1	300	10.5	1803	1950
2	300	12.8	1759	1614
3	300	10.2	1857	1913
4	300	8.7	1935	2078
5	300	9.1	1869	2094

 

Please pay close attention to retained velocities.

 

*TTSX / GMX: Be mindful of potential for narrow wounding on large animals at and beyond 150 yards (2200fps). Shot placement critical.

.376 Steyr	Imperial	Metric
A	.494	12.55
B	.501	12.73
C	15 deg
D	.473	12.01
E	.398	10.1
F	1.860	47.24
G	.350	8.89
H	2.350	59.7
Max Case	2.350	59.7
Trim length	2.340	59.5

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