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.375 Winchester


The .375 Winchester was released in 1978 as the initial chambering for Winchester’s Big Bore 94 lever action rifle. The .375 was a revised high power version of the .38-55 Winchester-Ballard black powder cartridge which, in 1894, was one of the initial chamberings of the then new Winchester M94 lever action rifle.

Designed by U.S gunmaker Charles H Ballard; historical authorities generally agree that the .38-55 Ballard was first introduced in 1884. Ballard’s first major innovation was the creation of an extremely well designed single shot rifle action. After patenting his action in 1861 Ballard sold the rights to use his design to various gun makers. In 1875 John M Marlin adopted the Ballard action which was used as a basis to build accurate rifles. In 1881 Marlin formed the Marlin Firearms company and it is around this time period that the first references can be found of the .38-55 Ballard proprietary cartridge being offered in the Marlin single shot No.4 Perfection.

The .38-55 Ballard earned a reputation as an extremely good cartridge for target shooting out to 300 yards. It was smaller than some of the more common bores in use at that time but produced a good trajectory and low recoil. The most common load consisted of a 255 grain .375 caliber bullet at 1200fps.

With the continued popularity of the .38-55 Ballard, Winchester adopted it as one of the two initial chamberings for their new M1894 Winchester rifle. This rifle is now most famous for its .30-30WCF chambering. After its adoption by Winchester the .38-55 cartridge later came to be called the .38-55 Winchester-Ballard but was also sometimes referred to as the .38-55 Winchester or simply the .38-55 as it was not usually confused with other chamberings. After the turn of the century many of the old black powder cartridges lost popularity as hunters switched to bolt action rifles and bottle necked rimless cartridges. Winchester eventually dropped the .38-55 chambering. Even though its popularity was limited, it continued to maintain a small following among black powder cartridge fans which still exists today.

The 1960’s was a time of great creativity, though it was also at this time that Winchester began to instigate cost cutting changes. Nevertheless in 1963, in an attempt to modernize the lever action rifle, Winchester released the Model 88 lever action rifle chambered for the .284 Winchester cartridge. The .284 cartridge was a flat shooting and hard hitting 7mm - a great all round cartridge, however sales of this rifle were poor and the M88 was soon dropped from production.

From the poor reception of the M88, Winchester designers came to the conclusion that the success of lever action rifle sales depended on classic designs. In 1978 Winchester released a new rifle and cartridge based on these principles. The new rifle was simply a beefed up stronger version of the original M94 lever action rifle and was named the Big Bore 94. Along with the revised rifle came a revised version of Winchester’s original M94 .38-55 chambering, the .375 Winchester.

Winchester factory loads for the .375 featured a 200 grain flat nose Powerpoint bullet at an advertised 2200fps and a 250 grain Powerpoint bullet at 1900fps. These velocities were recorded in a 24” test barrel and true velocities from 20” barrels were more in the region of 2100 and 1800fps respectively.

In 1981 the Winchester company was sold and renamed as the U.S Repeating Arms Company (U.S.R.A.C). Along with this change of hands came modifications to the Big Bore rifle (1982) incorporating side ejection to facilitate the mounting of a scope. The modified rifle was named the Big Bore XTR AE (angle eject). Two new Big Bore cartridges were also introduced at this time, the .307 and .356 Winchester, these were part of Winchester’s original intention to create a family of potent, high pressure cartridges for the Winchester lever action rifle.

Also at this time a fourth .400 caliber cartridge waited in the wings. But contrary to the hopes of the designers all three Winchester cartridges (.307, .356, .375) failed to obtain any lasting popularity. The .375 caliber rifle was the first to fall from production and by the mid 1990’s the .307 and .356 caliber rifles were also discontinued. Today these cartridges enjoy a small and quiet following among fans of unique lever action cartridges. Winchester continue to produce one of the two original factory loads for the .375, the 200 grain Powerpoint.

In comparison to the original .38-55 cartridge case, the .375 has thicker case walls and a stronger head. The case is .65” shorter than the .38-55, an odd decision as this potentially allows the .375 rated at 50,000CUP to be accidentally chambered in a .38-55 caliber rifle, the .38-55 being rated at 30,000CUP. Due to the fact that the .38-55 case is longer than the .375, it is unsafe to fire .38-55 ammunition in the big bore rifle. That said, a small number of Big Bore rifles were reamed to .38-55 and stamped 38-55/ .375 Winchester. These rifles, of which I have owned one, can fire both ammunition's safely.



Unfortunately, it is much easier to find fault with the .375 than it is to find inherent good qualities. Both factory and hand loads produce very poor muzzle velocities. Impact velocities are generally so low that the .375 struggles to produce disproportionate to caliber wounding. Where shot placement is not sound, the .375 can be a slow killer. Readers must understand that most conventional bullet designs struggle to expand at impact velocities below 1800fps, even though .375 Winchester bullets are designed to expand down to impact velocities of 1600fps. From a muzzle velocity of 2200fps, this leaves only a very small performance window. Were this cartridge loaded with a heavy Hornady XTP things may have been a lot different, but alas, there is no such bullet.

The one saving grace of this cartridge is that it the .375” bore is fairly wide to begin with while its heavy bullets are capable of delivering relatively deep penetration. Were it not for these factors, I am sure many game animals would not be recovered. But with the combination of a large bullet diameter and heavy flat pointed bullets, the .375 is able to produce reliable results.

As a lean game cartridge (such as hunting Black Tail in Oregon pines) the .375 bullets work acceptably well. But in truth wounds are not generally wider than that achieved with the .30-30 loaded with 150 grain bullets. There are certainly many stories as to how well this cartridge ‘flattens’ game but all too often we find that such things came about as a result of a spine shots which tells very little of what a cartridge is capable of when the chips are down. These matters aside, the .375 Winchester can be put to use on lean game, producing clean kills from pretty much any angle.

The .375 Winchester has some merit as a cartridge for use on larger bodied deer in heavy timber. Any velocity gains made via hand loading (safely) can be put to meaningful use. This is where this cartridge really comes into its own, fulfilling a role where the .30-30 is very much lacking.

It is extremely unwise to utilize the .375 as a ‘big game stopper’ as some seem to believe this cartridge is capable of achieving. At best the .375 can be considered a humble, clean killer of medium weight non-dangerous game. I am sure many would disagree with this but the truth is, were it any other way, this would be a much more popular cartridge. Sometimes being able to ‘eat up to the bullet hole’ is a good thing. Other times this description simply alludes to the fact that you might just get eaten yourself one day.

In order to optimize performance, hunters should strive to place shots into the forwards portion of game chest cavities (see .30-30 and also Game Killing section) to destroy the autonomic plexus along with the major locomotive muscles and bones. Those who are fans of the traditional .30-30WCF can view the .375 as being of a similar nature but with the ability to produce deeper penetration. Thoughts of wider wounding should be put aside.

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Factory ammunition

As previously stated, Winchester are the only manufacturer to produce a .375 loading, the 200 grain Powerpoint at a realistic 2100fps. From this velocity, the Powerpoint bullet breaks 1800fps at just 80 yards, beyond which this bullet design struggles to expand. Those who are serious about accuracy may be able to use the Powerpoint out to greater ranges (as I have done). The key is to keep shots well forwards towards the CNS ganglia at the front of the chest.


Hand loading

Using hand loads it is possible to supersede factory loads by up to 100fps. However results in the field usually show no improvement in performance on game. Best results in the 20” barreled Big Bore come from fast burning powders in the IMR/ H4198 range achieving velocities of 2200fps with 200 grain bullets, 2000fps with 220 grain bullets and 1850fps with 250-255 grain bullets.

At the time of writing, only two manufacturers produce .375 caliber flat nose bullets suitable for the Big Bore 94’s tube loading magazine. Sierra produce a 200 grain bullet, while Barnes produce their original 255 grain bullet. Both are flat nose soft point conventional bullet designs. Hornady no longer produce their 220 grain flat point due to poor sales. This was a relatively tough bullet that struggled to produce good results at and below 1800fps.

The 200 grain Sierra flat point is best suited to medium to larger bodied deer weighing up to 320kg (700lb), doing its best work inside 100 yards. Sierra have done their very best to make this bullet design work at low impact velocities by cutting deep notches into the bullet jacket while also ensuring the flat point has plenty of exposed lead. Nevertheless, one should consider 170 to 175 yards or 1600fps as the maximum effective range for the Sierra, taking wind drift and other accuracy issues into account. The Sierra does not have a high SD, therefore hunters need to maintain realistic expectations as to just how far it will penetrate. On light to medium sized deer this bullet can be used from all angles, but on large bodied deer expect some limitations. It is very hard for a bullet maker to create a bullet that will produce both full expansion on lean game and deep penetration on larger bodied animals with such a small operating (velocity) window.

The 255 grain Barnes Original has a very thin jacket to aid expansion but like most other bullet designs of this type, struggles to produce optimal performance below 1800fps. Like the Sierra flat point, an impact velocity of 1600fps (100 yards) should be considered the absolute cut off point for this bullet. Were Barnes to offer a 200 grain soft jacketed bullet we may have had a winner. But on the other hand, there would no doubt be complaints from the milk jug hunters. In any case the 255 grain Barnes Original is better suited where deep penetration is required above other factors. The Barnes bullet cannot be expected to produce a wide wound channel due to low velocity and low hydraulic forces.


Closing comments

It is sometimes all to easy to hold a large cartridge in one’s hand and assume great expectations. I have loaded the .375 Winchester every which way but loose in an attempt to enhance its killing performance but unfortunately the .375 Winchester simply is what it is.

The .375 Winchester is a humble, clean killing cartridge, capable of relatively deep penetration on medium game out to moderate ranges chambered in a lightweight handy carbine. By using the right bullet at the right ranges combined with the right shot placement the .375 can be put to good use.

Suggested loads: .375 Winchester

Barrel length: 20”




Sectional Density

Ballistic Coefficient

Observed MV Fps




Winchester 200gr FP







Sierra 200gr FP






Suggested sight settings and bullet paths













Bt. path
















Bt. path







Sight height 1.6” (Scoped XTR AE rifle).


At yards














375 winchester final

.375 Win















Max Case



Trim length



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