A deep analysis of the .30-06 Springfield and the .303 British cartridges. This article outlines the history, market conditions, size, shape, ballistic performance, and other important factors for these two classic rounds. After reading, you’ll understand the differences so you can make the best choice for target shooting, competition, and hunting.

The .30-06 Springfield is one of the oldest cartridges still used today. Dating back to 1906, the round was standard ammo for American troops in World War I. But there is another rifle cartridge with a military history that outdates even the Springfield. The .303 British, which also saw action in the First World War, was a common load for British and Commonwealth forces, and it has remained a popular option for deer and large-game hunting across North America, especially in Canada.

With many similarities and parallel histories, it’s no surprise that these rounds compete for sales and use. They may also compete for a place in your gun safe.

303 British vs .30-06: Fast Answers

Need answers right now? Here’s a quick summary of the advantages for each cartridge:

Advantages of the .303 British

• Less recoil
• A unique, less typical cartridge

Advantages of the .30-06 Springfield

• Faster speed
• More power
• Straighter trajectories
• Greater variety and availability
• Lower prices

.303 British vs .30-06 Springfield: Specs

	.303 British	.30-06 Springfield
Released	1889	1906
Bullet Diameter	0.312 inches	0.308 inches
Neck Diameter	0.34 inches	0.34 inches
Base Diameter	0.46 inches	0.471 inches
Case Length	2.222 inches	2.494 inches
Case Capacity	3.64 cubic centimeters	4.4 cubic centimeters
Overall Length	3.075 inches	3.34 inches
Bullet Weights	150 - 180 grains	120 to 220
Typical Firearm	Bolt-action rifle	Bolt-action rifles

What’s the Same?

Physically, they are similar in bullet weight and base diameter. They have similarities in size, shape, bullet weight, and many other physical features, but what’s most important to some shooters is the simple fact that they are both loaded into bolt-action rifles. Both the .30-06 and the .303 are fired from easy-to-use bolt actions, which are considered a top choice for long-range accuracy and precision.

Size and Shape

The size and shape differences are most noticeable in the case. The .30-06 Springfield’s case is both wider and longer, making the entire cartridge noticeably bigger. The difference in overall length (3.075 inches vs 3.34 inches) gives the Springfield a larger profile; this difference is manifested in case capacity, where the Springfield has a notable size advantage.

Bullet Weights

The .303 is available with bullets ranging from 150 to 180 grains. The .30-06 is available with the same weights, but users can also find options as light as 120 and as heavy as 220, creating more options for shooters.

Market Conditions

The market matters to shooters. No matter which cartridge you select, you need to know that you can find ammo, and, preferably, the ammo will be reasonably affordable. In this area, .30-06 Springfield ammunition has a clear advantage, as it comes in a greater variety, is more common on store shelves, and often has a better price.

At least here in the U.S., the .30-06 is a better option for availability, variety, and pricing. 303 British ammo options just aren’t as plentiful and are often more expensive.

.303 British vs .30-06 Springfield Ballistics

The .30-06 may have an advantage in market conditions, but how does that larger case capacity and different bullet profile impact velocity, trajectory, and performance? We compared four pairs of cartridges, all with the same weights from the same brand, to create a consistent, apples-to-apples examination.

Velocity

	Muzzle (fps)	100	200	300	400	500
.303 British 150-gr Power-Shok Rifle (Federal)	2,690	2,442	2,208	1,988	1,780	1,590
.30-06 Springfield 150-gr Power-Shok Rifle (Federal)	2,910	2,616	2,340	2,081	1,839	1,619
.303 British 180-grain Power-Point (Winchester)	2,460	2,233	2,018	1,817	1,629	1,459
.30-06 Springfield 180-grain Power-Point (Winchester)	2,700	2,468	2,247	2,038	1,840	1,657
.303 British 180-gr Core-Lokt (Remington)	2,460	2,125	1,818	1,545	1,314	1,138
.30-06 Springfield 180-gr Core-Lokt (Remington)	2,700	2,469	2,250	2,041	1,844	1,663
.303 British 150-grain InterLock SP (Hornady)	2,685	2,441	2,211	1,993	1,789	1,601
.30-06 Springfield 150-grain InterLock SP (Hornady)	2,910	2,637	2,381	2,139	1,911	1,700

The .30-06 Springfield has a clear speed advantage, although it’s not massive. When comparing two cartridges with the same weights (150 vs 150, for instance), the .30-06 is faster. This should come as no surprise considering the larger case size, which means more propulsion behind the bullet.

Energy

	Muzzle (ft-lbs)	100	200	300	400	500
.303 British 150-gr Power-Shok Rifle (Federal)	2,410	1,987	1,624	1,316	1,055	842
.30-06 Springfield 150-gr Power-Shok Rifle (Federal)	2,820	2,279	1,823	1,442	1,126	873
.303 British 180-grain Power-Point (Winchester)	2,418	1,993	1,628	1,320	1,060	851
.30-06 Springfield 180-grain Power-Point (Winchester)	2,913	2,433	2,018	1,659	1,354	1,097
.303 British 180-gr Core-Lokt (Remington)	2,418	1,805	1,321	954	690	518
.30-06 Springfield 180-gr Core-Lokt (Remington)	2,913	2,436	2,022	1,666	1,360	1,105
.303 British 150-grain InterLock SP (Hornady)	2,401	1,985	1,628	1,323	1,066	854
.30-06 Springfield 150-grain InterLock SP (Hornady)	2,820	2,317	1,888	1,523	1,216	963

With faster speeds and bullets of the exact same weight, it’s no surprise that the .30-06 Springfield hits harder. In some of our comparisons, however, the .303 performs well down range. For example, the Federal products (listed at the top) show a power advantage of 410 ft-lbs at the muzzle. However, the .30-06’s advantage has narrowed to 31 ft-lbs at 500 yards.

While the Springfield has more power, the British should not be considered weak. Most of the rounds have over 2,400 ft-lbs at the muzzle and over 800 ft-lbs at 500 yards, which is plenty of force for deer and medium-sized game hunting, especially at moderate distances.