Sometime prior to 1965, gunsmithing great – Ellwood Epps – decided to make an improved version of the venerable 303 British cartridge. Apparently, he conferred with P.O. Ackley in the course of this development project.
If you compare a 303 Epps Improved fired case to images of improved cartridges – developed by P.O. Ackley – like 250/3000 Improved (Ackley), 257 Improved (Ackley), 303-30 Ackley Improved, 30-06 Improved (Ackley) – from the ‘40s and 50’s – you'll see that there is a lot of commonality in the design philosophy. Specifically, like the Ackley improved cartridges, that came before, Epps adopted an approach of going with nearly-parallel case sides and a steep shoulder, angle leading to a relatively short neck.
These improvements, of course, led to increased case capacity – meaning that the cartridge could be loaded-up more, without exceeding the pressure limits of the relevant action.
It has been reported that, in his original interactions with Ackley, Epps suggested that he was interested in making these improvements to the 303 British case mostly to extend case life – by reducing case taper. This was based on the suggestion that reduced body taper lessens the rearward pressure effects on the bolt and lugs (bolt thrust). Sharp shoulder angles inhibit forward brass flow, which reduces the need to trim cases as often, whereas unnecessary case taper can lead to case stretching.
Epps’ specific solution was to increase the shoulder angle to 35 degrees from 16. At the same time, he decreased the body taper by over 50 thou.
However, having introduced this design change, Epps quickly found that the improved cartridge could also be loaded up – especially in stronger actions, like the no.4 and the P-14. I understand that the latter is rated for 59,000 PSI.
There is at least one book that provides loading data for both the 303 British and 303 Epps Improved and the author has posted information on his loads, such as the following:
A standard 303 British versus the 303 Epps Improved –
2700 fps versus 2865 fps (approx 5% improvement)
2440 fps versus 2650 fps (approx 8% improvement)
These 303 Win-type results were obtained in a No.4 and the numbers which can be SAFELY obtained in a P-14 are even better. Specifically, the resulting improved cartridge showed a 15 % velocity enhancement over the standard 303 British when fired from the P-14. This is a decent deal since the Epps spec is easy to get along with – since Epps 303 Improved cases are created just by fire-forming standard 303 rounds. My Epps improved chambered custom P-14 holds 1-1.5 inch groups – even when I am fireforming standard 303 reloads (made from 1970’s Chinese X54R scavenged powder an steel core 150 gr projectiles). This is all I've done with the gun so far – since I don't yet have reloading dies for the cartridge.
And yes, all you have to do is ream out your No.4 or P-14 – and there are no reported feeding issues – at least that I have seen.
Everybody knows that the Australians have REALLY taken to wildcat cartridges based on the 303 British round – like no one else. It follows that 303 Epson proved ended-up being a massive hit in Australia; where I would guess there may be ten times as many guns – in this caliber – as you may currently find in Canada. In fact, 303 Epps Improved dies are still sold as a standard die set (not an expensive custom die set) by Australia’s domestic die maker (Simplex).
So, what is the point? Can't you just re-barrel a No.4 to 308 or just shoot a P17? Sure, but Epps clearly liked 303 British – as do others, even now. And IMO, there are better reasons to like 303 Epps now. This is because we all now have the ability to buy CHEAP and good X54R surplus ammo (which was not so in the 60’s). And this stuff can be taken apart and the bullets and powder can be reused to reload 303 Brit – BUT with the need to load down on the powder.
How much handier would it be to just do a 1-to-1 dump of a X54R powder load into a boxer-primed 303 Epps case and to reseat the bullet? You’d end-up with a really nice bolt gun (much nicer than any Mosin!), shooting noncorrosive reworks of ex- X54 rounds. The load data I’ve seen for 303 Epps seems to call for the same powders and bullets as X54 – so I doubt there’d be any issue with the 1-to-1 dump of a X54R powder load thing.
I'm gonna be testing this theory out soon – and will post results here. And yes, I will start with standard 303 British loads and will work up – checking for pressure signs. Thanks in advance for all the gratuitous warnings that I'm sure are coming my way. However, honestly guys, I've been reloading for over 40 years – without incident – and don't really appreciate people whose well-known first instinct is to post some unfounded comment that “you're gonna blow your face off”.
One big caveat here is I wouldn't even dream of trying to load-up 303 Epps with the kind of garbage brass that you get – left over – from firing US commercial 303 British ammo. I’ll be using nothing but top-quality brass.
What are your thoughts about 303 EPS improved? Do you have any experience with this cartridge?
If you compare a 303 Epps Improved fired case to images of improved cartridges – developed by P.O. Ackley – like 250/3000 Improved (Ackley), 257 Improved (Ackley), 303-30 Ackley Improved, 30-06 Improved (Ackley) – from the ‘40s and 50’s – you'll see that there is a lot of commonality in the design philosophy. Specifically, like the Ackley improved cartridges, that came before, Epps adopted an approach of going with nearly-parallel case sides and a steep shoulder, angle leading to a relatively short neck.
These improvements, of course, led to increased case capacity – meaning that the cartridge could be loaded-up more, without exceeding the pressure limits of the relevant action.
It has been reported that, in his original interactions with Ackley, Epps suggested that he was interested in making these improvements to the 303 British case mostly to extend case life – by reducing case taper. This was based on the suggestion that reduced body taper lessens the rearward pressure effects on the bolt and lugs (bolt thrust). Sharp shoulder angles inhibit forward brass flow, which reduces the need to trim cases as often, whereas unnecessary case taper can lead to case stretching.
Epps’ specific solution was to increase the shoulder angle to 35 degrees from 16. At the same time, he decreased the body taper by over 50 thou.
However, having introduced this design change, Epps quickly found that the improved cartridge could also be loaded up – especially in stronger actions, like the no.4 and the P-14. I understand that the latter is rated for 59,000 PSI.
There is at least one book that provides loading data for both the 303 British and 303 Epps Improved and the author has posted information on his loads, such as the following:
A standard 303 British versus the 303 Epps Improved –
2700 fps versus 2865 fps (approx 5% improvement)
2440 fps versus 2650 fps (approx 8% improvement)
These 303 Win-type results were obtained in a No.4 and the numbers which can be SAFELY obtained in a P-14 are even better. Specifically, the resulting improved cartridge showed a 15 % velocity enhancement over the standard 303 British when fired from the P-14. This is a decent deal since the Epps spec is easy to get along with – since Epps 303 Improved cases are created just by fire-forming standard 303 rounds. My Epps improved chambered custom P-14 holds 1-1.5 inch groups – even when I am fireforming standard 303 reloads (made from 1970’s Chinese X54R scavenged powder an steel core 150 gr projectiles). This is all I've done with the gun so far – since I don't yet have reloading dies for the cartridge.
And yes, all you have to do is ream out your No.4 or P-14 – and there are no reported feeding issues – at least that I have seen.
Everybody knows that the Australians have REALLY taken to wildcat cartridges based on the 303 British round – like no one else. It follows that 303 Epson proved ended-up being a massive hit in Australia; where I would guess there may be ten times as many guns – in this caliber – as you may currently find in Canada. In fact, 303 Epps Improved dies are still sold as a standard die set (not an expensive custom die set) by Australia’s domestic die maker (Simplex).
So, what is the point? Can't you just re-barrel a No.4 to 308 or just shoot a P17? Sure, but Epps clearly liked 303 British – as do others, even now. And IMO, there are better reasons to like 303 Epps now. This is because we all now have the ability to buy CHEAP and good X54R surplus ammo (which was not so in the 60’s). And this stuff can be taken apart and the bullets and powder can be reused to reload 303 Brit – BUT with the need to load down on the powder.
How much handier would it be to just do a 1-to-1 dump of a X54R powder load into a boxer-primed 303 Epps case and to reseat the bullet? You’d end-up with a really nice bolt gun (much nicer than any Mosin!), shooting noncorrosive reworks of ex- X54 rounds. The load data I’ve seen for 303 Epps seems to call for the same powders and bullets as X54 – so I doubt there’d be any issue with the 1-to-1 dump of a X54R powder load thing.
I'm gonna be testing this theory out soon – and will post results here. And yes, I will start with standard 303 British loads and will work up – checking for pressure signs. Thanks in advance for all the gratuitous warnings that I'm sure are coming my way. However, honestly guys, I've been reloading for over 40 years – without incident – and don't really appreciate people whose well-known first instinct is to post some unfounded comment that “you're gonna blow your face off”.
One big caveat here is I wouldn't even dream of trying to load-up 303 Epps with the kind of garbage brass that you get – left over – from firing US commercial 303 British ammo. I’ll be using nothing but top-quality brass.
What are your thoughts about 303 EPS improved? Do you have any experience with this cartridge?
