Critique of the .300 Winchester Magnum

.300 Win. Mag. PPU ammunition
.300 Win. Mag. PPU ammunition

Why did Winchester design their .300 Win. Mag. to have such a short neck? Why couldn’t it have had a neck as long as the .308 Norma Magnum? Doesn’t this reduce the usable powder capacity and make it hard to seat long, heavy bullets so that they are tightly grasped by the neck of the case? What rifle powders have you found work best in the .300 Win. Mag?
– Michael Purcell

.300 Win. Mag. Cartridge Specs
.300 Win. Mag. Cartridge Specs

We all thought that “Big Red” would legitimise the .30-338 wildcat, but it would have been dimensionally too close to the .308 Norma to succeed in the marketplace. They also wanted it to give the .300 Wby. Mag. a run for its money. Winchester‚Äôs other short magnums all used a 2.500″ case length, but for the .300 they increased it to 2.620″ and moved the shoulder forward 0.156″. This was done to create all the case capacity possible and still fit in standard .30-06 length actions. Many shooters have been critical of the short neck, although I don‚Äôt understand why. The accepted standard is a minimum of one calibre of neck length. The .300 Win. Mag‚Äôs neck is only .264″, which falls short of this criteria. So what? The .300 Win. Mag. is the most popular .30 magnum of them all, and has won an enviable reputation as a long range target cartridge, holding quite a few records. So the short neck obviously poses no problems. Some claim that with the forward shoulder and short neck, long, heavy bullets must be seated too deeply into the case, reducing powder capacity. But in fact, pushing the shoulder back would reduce powder capacity a lot more than would seating a 200gn bullet into the case the same distance. So, how could that have been better? Good game bullets include the 180gn and 200gn Nosler Partition, AccuBond, Swift A-Frame, Barnes X and Woodleigh PP SN. Many slow burning powders work well in the .300 Win. Mag., but whenever I have a rifle in this calibre to test Reloder 22 is always my first choice. Another powder that works well is AR2213SC. Like all magnums, the .300 Win. Mag. shoots best with loads that are near maximum and when the charge comes close to filling the case. For big game I am a big fan of 200gn bullets pushed along with Re- 25.




Like it? Share with your friends!

What's Your Reaction?

super super
fail fail
fun fun
bad bad
hate hate
lol lol
love love
omg omg
Marcus O'Dean