.270 Weatherby Magnum

colspan="3" style="background: lightsteelblue; text-align: center; vertical-align: middle;"

| .270 Weatherby Magnum colspan="3" style="text-align: center; font-size: 90%; border-bottom: 1px solid #aaa; line-height: 1.25em;"

| File:Munit03.jpg
.270 Weatherby 2nd from left Type Rifle / Hunting Place of origin USA colspan="3" style="background: lightsteelblue; text-align: center; vertical-align: middle;"

| Production history Designer Roy Weatherby Designed 1943 Manufacturer Weatherby colspan="3" style="background: lightsteelblue; text-align: center; vertical-align: middle;"

| Specifications Parent case .300 H&H Magnum Case type Belted, bottleneck Bullet diameter .277 in (

 mm

)

Neck diameter .303 in (

 mm

)

Shoulder diameter .492 in (

 mm

)

Base diameter .512 in (

 mm

)

Rim diameter .531 in (

 mm

)

Rim thickness .220 in (

 mm

)

Case length 2.55 in (

 mm

)

Overall length 3.25 in (

 mm

)

Rifling twist 1-10" Primer type Large rifle magnum colspan="3" style="background: lightsteelblue; text-align: center; vertical-align: middle;"

| Ballistic performance Bullet weight/type Velocity Energy style="vertical-align:middle; border-bottom: 1px dotted #aaa;

" | 110 gr (

 g)

HP||style="border-bottom: 1px dotted #aaa;

"|3,528 ft/s (

 m/s)

||style="border-bottom: 1px dotted #aaa;

"|3,041 ft·lbf (

 J)

style="vertical-align:middle; border-bottom: 1px dotted #aaa;

" | 130 gr (

 g)

X||style="border-bottom: 1px dotted #aaa;

"|3,338 ft/s (

 m/s)

||style="border-bottom: 1px dotted #aaa;

"|3,217 ft·lbf (

 J)

style="vertical-align:middle; border-bottom: 1px dotted #aaa;

" | 140 gr (

 g)

BT||style="border-bottom: 1px dotted #aaa;

"|3,242 ft/s (

 m/s)

||style="border-bottom: 1px dotted #aaa;

"|3,268 ft·lbf (

 J)

style="vertical-align:middle; border-bottom: 1px dotted #aaa;

" | 150 gr (

 g)

SBT||style="border-bottom: 1px dotted #aaa;

"|3,161 ft/s (

 m/s)

||style="border-bottom: 1px dotted #aaa;

"|3,329 ft·lbf (

 J)

Test barrel length: 26"
Source: Accurate Powder

The .270 Weatherby Magnum was the first belted magnum based on the .300 H&H Magnum to be developed by Roy Weatherby. It has the characteristic double-radius shoulders and is necked down to accommodate the .277in bullets. Being a proprietary cartridge, the .270 Weatherby has no official SAAMI maximum pressure limit. Weatherby factory ammunition is loaded to 71,000 PSI. The first Weatherby cartridge to be used in Africa was the .270 Weatherby on a jackal on June 8, 1948.

Performance

Given its higher pressure and larger case which holds more powder than the .270 Winchester, the .270 Weatherby has about 200 ft/s faster performance with any particular bullet weight. This performance comes at the cost of more recoil and barrel heat. In addition, a long barrel is necessary to take advantage of extra powder to gain maximum velocity. The cartridge is excellent at long-range hunting, but is not well suited to high-volume shooting such as varmint hunting.

For those handloading their own cartridges, this is an easy round to load. It does best with full-power loads and is not well-suited for reduced loads. Ed Weatherby, son of Roy Weatherby says that the .270 Weatherby is his favorite caliber. As he puts it, there just isn't a better long-range deer caliber. He goes on to mention that it is also quite effective for elk, and antelope.

Categories

Cartridge:rifles