The 307 Winchester cartridge was introduced in 1982 for a lever-action rifle equipped with a tubular magazine. It was designed by its makers, Winchester, to shoot flatter with superior shot placements when coupled with the slick and handy model 94 lever action rifle.
The 307 Win’s design was based on the .308 Winchester, with a semi rim added to aid extraction, and more thickness to the case walls than its parent case. Its main purpose was to become the most popular short-action, big-game hunting cartridge worldwide, taking over from its predecessor and parent, the .308 Win.
Case
With a rimmed bottle-neck, the case has an overall length of 2.56 inches, and a base diameter of 0.506. Because of its thicker walls, although the design is akin to the .308 Win, the .307 offers slightly less case capacity than its parent case.
Bullet
The bullet diameter for the 307 Win is 0.308 inches, meaning it is a .30 caliber round. 180 grains can be fired at a muzzle velocity of 2510 fps to generate 2519 ft lb of muzzle energy.
130 and 150 grain loads can also be used, with a 150-grain factory load churning up to 2760fps. It is also quite rare, but a 170-grain load can be used as well, such as the 170 grain Speer flat point. It is suitable for light-bodied games, but at full .307 velocities, it is too soft for use on larger-bodied medium games, making them unable to cope with taking shots and unable to produce exit wounds. Winchester recommends that only flat-nosed bullets be used in the .307. Round-nose bullets may be dangerous due to the extra recoil inertia which could result in cartridge detonation within tubular magazines of the 94. Because of such safety concerns, flat-nosed bullets are always used.
Rifle chambering the 307 Win
The Winchester Big Bore Model 94 Angle Eject rifle, modified to eject fired cases to the side instead of straight up to give allowance for a scope, was the only rifle produced to fire the cartridge, though the competitor, Marlin Firearms, created some prototype model 336 rifles chambered in .307 Win. It is still commercially loaded today, but many handload it to gain better performance and accuracy.
An adequate 200-yard deer rifle is also capable of unleashing the potential of the 307 Winchester. Unfortunately, neither that (nor its other top features) wasn’t enough to capture the hearts and imaginations of hunters, and today, the .307 Winchester is nearly obsolete.
The .308 Marlin Express cartridge was designed by Marlin Firearms and Hornady in 2007. It is based on the .307 Winchester with the intention of matching the performance of the .308 Winchester. To work in lever-action rifles, the cartridge has a slightly shorter, semi-rimmed case similar to that of the .220 Swift, as introduced in Hornady's LEVERevolution family of cartridges, the highest velocity production cartridge developed for lever-action rifles with tubular magazines. It's chambered in Marlin's Model 308MX and 308MXLR rifles, and it's fired from a Marlin Model 336 action.
The .308 Marlin Express is built on a new case, not a necked-down version of any prior case, albeit it looks very similar to a.307 Winchester case with a shoulder setback of.0998 inches. It is a rimmed cartridge with somewhat better performance than the .307 Winchester and comes close to the .300 Savage. Its claimed ballistics fall somewhere in the middle of those cartridges.
Hornady's LEVERevolution flex-tip spitzer bullet idea was used in the creation of the .308 Marlin Express. This has been re-optimized, particularly for the .308 Marlin Express, resulting in a flatter trajectory with more maintained velocity and energy downrange. The new 160 grain .308 Marlin Evolution bullet features a larger ogive and a greater ballistic coefficient (BC.400) than the .30-30 Evolution bullet from last year. The BC of the 160 grain .30-30 Evolution bullet is .330..
On a number of large game species, the newly redesigned 160-grain Evolution bullet has already been shown to be quite successful. As a result, the .308 Marlin Express became the newest, quickest, flattest-shooting, and most adaptable of the rimmed hunting cartridges designed for use in lever-action rifles as a result. It transforms the Marlin 336 rifle into a real "all-around" weapon for hunting CXP2 (deer) and CXP3 (elk) animals.