.270 Winchester (using Sierra bullets)
Date: Nov 09 2022
The .270 Winchester was introduced in 1925 in the bolt-action Winchester Model 54 rifle, the predecessor to the famous Model 70. It offers a unique blend of accuracy, flat trajectory, modest recoil and has proven reliable on deer-sized game. It became almost instantly popular with big-game hunters and remains in widespread use the world over. While it is a quintessential “deer cartridge,” when loaded with premium hunting bullets it is also suitable for larger species such as elk and moose.
While it is commonly suggested that the .270 case is based on a necked down .30-06 Springfield, in reality it is .046 inch longer (2.540 inches) which is the same length as the .30-03 Springfield case that is technically the “parent” cartridge. For this reason, it is not suggested to neck .30-06 cases down to accept .277-inch bullets.
It has been published repeatedly that as .270 pressures climb and approach maximum, if the handloader will continue to increase powder charges pressures will decrease as velocities continue to increase. This is untrue and should never be attempted! No credible lab has ever been able to substantiate this claim, and neither will one suggest increasing charges beyond maximum loads that have been pressure tested using sophisticated equipment.