Overrated .303 Epps
Q: I have been so impressed with data on the internet which shows some astounding velocities for the .303 Epps that I've decided to have a rifle built in this calibre. I obtained an M17 Enfield rifle, a Walther barrel and a laminate stock for this project. What can you tell me about Epps? What kind of performance could I expect from this wildcat?
A: Ellwood Epps was an oldtime gunsmith of Clinton, Ontario, Canada, who has been called the "Canadian Ackley". He is known for a line of improved wildcat cartridges based on the .303 British case. They included a .25-303 and 6.5-303 which duplicated the ballistics of the .257 Ackley Improved and 6.5x55 Swede as well as larger calibres - .303, 8mm, 338 and .358.
The .303 Epps was reasonably popular with Canadian shooters who had their .303 P-14 Enfield rifles rechambered; the Lee Enfield just wasn't strong enough to contain the higher pressures. Actually, you'd have done better to get a P-14 which was designed to handle the rimmed .303 cases and has an angled rear face in the magazine to prevent the rims from getting jammed over each other. It will take a lot more work to make the M-17 feed .303s properly. I don't know what you read about the .303 Epps on the Internet, which is the biggest source of misinformation there is, but like with most other improved cartridges, you can't expect to get more of a velocity increase than from 100 to 150fps over the standard .303. The reality is: there's simply no substitute for cubic capacity, and larger the case the greater the velocity it gives. That's why we buy magnums to gain extra performance. I've seen the .303 Epps credited with driving the 150gn bullet at 3300fps which is ridiculous as it would strain a .30 magnum to get that velocity.