.350 Legend: Specs, Ballistics and Origins

.350 Legend is a straight-walled centerfire rifle cartridge from Winchester, launched in 2019 and aimed at deer hunters. Winchester says it was designed for deer hunting out to 250 yards, and SAAMI lists it as a standardized centerfire rifle cartridge.

What .350 Legend is

Winchester describes .350 Legend as a straight-wall cartridge introduced in the context of deer hunting. The company says several states had approved straight-wall cartridges, allowing hunters to use rifles during firearm season, and that Winchester launched the 350 Legend in 2019.

That legal context is important, but it should be handled carefully. Some jurisdictions have rules that refer to straight-walled cartridges, but hunting regulations are state, provincial, and season specific. Before using .350 Legend for deer or any other game, confirm the current regulation language with the wildlife agency for the place you plan to hunt.

At the cartridge level, Winchester lists the basic .350 Legend specifications as a .357-inch bullet diameter, 1.71-inch shellcase length, and 2.26-inch overall cartridge length. SAAMI’s current centerfire rifle standard lists the cartridge in its centerfire rifle specifications and provides the detailed dimensional, pressure, and velocity reference data.

Origins and design rationale

Winchester says .350 Legend ammunition was scheduled to be available in April 2019, and later described the cartridge as launched in 2019. The cartridge was positioned around straight-wall hunting use, especially for deer hunters in places where those rules matter.

Winchester also says the .350 Legend shellcase is a new design. According to Winchester, the cartridge has no parent case, but it uses the same .378 nominal rim diameter as .223 Remington. That is a useful distinction: Winchester identifies the rim diameter relationship, while also saying the .350 Legend case itself is not derived from a parent case.

The cartridge’s straight-walled design is part of its identity. Winchester’s own straight-wall discussion connects the rise of cartridges such as .350 Legend with jurisdictions that approved straight-wall cartridges for rifle use during firearm seasons. The practical takeaway for hunters is simple: the cartridge was built for the straight-wall hunting category, but the law still depends on the exact current rules where you hunt.

Winchester says .350 Legend is not compatible with standard .223 Remington or 5.56mm magazines and requires a slightly different magazine because of its cartridge dimensions. Winchester also says 1:16 twist-rate barrels have stabilized a variety of .350 Legend bullet weights and types.

SAAMI specifications

SAAMI Z299.4-2025 is the current SAAMI centerfire rifle standard, and SAAMI says the standard provides pressure, velocity, and dimensional characteristics for centerfire rifle sporting ammunition. SAAMI lists .350 Legend in that standard.

Key SAAMI .350 Legend specifications include:

Specification	SAAMI .350 Legend value
Standard velocity and pressure test barrel	16.000 inches
Optional rifling data	6 grooves, 16.00-inch right-hand twist

The same SAAMI listing gives the standard velocity and pressure test barrel for .350 Legend as 16.000 inches.

SAAMI’s cartridge and chamber drawing also lists optional rifling data of six grooves with a 16.00-inch right-hand twist. That lines up with Winchester’s FAQ statement that 1:16 twist-rate barrels have shown stabilization with a variety of .350 Legend bullet weights and types.

Published .350 Legend ballistics

Published ballistics vary by load and by the barrel or test standard used. For .350 Legend, the fact pattern from Winchester and SAAMI gives a useful snapshot of common bullet weights and velocities.

SAAMI velocity data

SAAMI’s velocity table for .350 Legend lists these bullet weights and velocities:

Bullet weight	SAAMI listed velocity
145 grain	2,250 fps
155 grain	2,200 fps
180 grain	1,985 fps
255 grain	1,020 fps

These figures are part of SAAMI’s standardized centerfire rifle data, not a full hunting trajectory table. They are best read as reference values from the standard.

Winchester published load data

Winchester publishes several .350 Legend load figures. Its Deer Season XP listing gives the X350DS .350 Legend load as a 150-grain Extreme Point with a .223 ballistic coefficient, 2,325 fps muzzle velocity, and 1,800 ft-lb muzzle energy.

Winchester’s .350 Legend FAQ gives additional load data with barrel lengths included:

Winchester load	Bullet	Barrel data stated by Winchester	Muzzle velocity	Muzzle energy
X3501	180-grain Power Point	20-inch barrel	2,100 fps	1,762 ft-lb
X350DS	150-grain Extreme Point	16-inch barrel	2,225 fps	1,649 ft-lb
USA3501	145-grain FMJ	16-inch barrel	2,250 fps	1,630 ft-lb

For hunters, the most relevant entries here are the hunting bullets Winchester identifies as Deer Season XP Extreme Point and Power Point. The 145-grain FMJ entry is still useful as published velocity and energy data, but Winchester’s listed bullet type for that load is Full Metal Jacket.

.350 Legend vs .450 Bushmaster

A factual comparison between .350 Legend and .450 Bushmaster should stay close to published data. Both appear in SAAMI’s centerfire rifle standard, and Winchester lists Deer Season XP loads for both cartridges.

SAAMI velocity comparison

Cartridge	SAAMI bullet weights and velocities
.350 Legend	145 grain at 2,250 fps, 155 grain at 2,200 fps, 180 grain at 1,985 fps, 255 grain at 1,020 fps

The SAAMI table lists several .350 Legend bullet weights and velocities.

Winchester Deer Season XP comparison

Winchester’s Deer Season XP listing gives a direct product-line comparison:

Winchester Deer Season XP load	Bullet	Ballistic coefficient	Muzzle velocity	Muzzle energy
.350 Legend X350DS	150-grain Extreme Point	.223	2,325 fps	1,800 ft-lb
.450 Bushmaster X450DS	250-grain Extreme Point	.210	2,200 fps	2,686 ft-lb

In that Winchester listing, the .350 Legend load uses a 150-grain bullet at a higher listed muzzle velocity, while the .450 Bushmaster load uses a 250-grain bullet and has higher listed muzzle energy. The listed ballistic coefficients are close, with Winchester listing .223 for the .350 Legend X350DS and .210 for the .450 Bushmaster X450DS.

That does not make one cartridge universally better. It only shows what Winchester and SAAMI publish for those specific loads and standards. A hunter choosing between them should match the cartridge, firearm, ammunition, local hunting rules, and intended use.

Bottom line for deer hunters

Winchester’s .350 Legend is a 2019 straight-walled cartridge built around deer hunting, with Winchester stating a design intent for deer out to 250 yards. SAAMI standardizes the cartridge and lists a 16 inch standard test barrel.

For regulations, do not rely on the cartridge name alone. Check the current hunting digest, rule text, and any caliber, case length, or straight-wall definitions published by the state or provincial wildlife agency where you plan to hunt.