338-03 Enfield wildcat build

[K223]

So as you’ve probably figured from the title I’m planning to rechamber and rebarrel a garbage rod Enfield into a 338 caliber while keeping the parent 303 case. Has anyone done a build like this previously and has any advice as far as case sizing or even rifle build tricks that they’ve come across?

 

[Incurable Collectoer]

I was given a Martini Enfield from an estate of a friend that has been reworked from a .303 Brit to a .338-.303 Improved. I managed to get the reloading dies and some already formed brass as well. Now I have just ordered a bullet mould so pretty soon I should be able to take the gun out to the range.

 

[Andy]

The 303 British has been necked up and down to every conceivable bore size and usually blown out at the same time. What you'd effectively be building is a rimmed and lengthened 338 Federal.

Dies and reamer will be custom, but if it's on a strong action like a P14 or Ruger #1, you could use 338 Federal Load Data.

 

[K223]

Where did you manage to find custom dies may I ask? And is there any reason you are moulding bullets rather than buying jacketed 338 bullets?

 

[Incurable Collectoer]

The dies were a part of the estate so I bought then and the brass with a bullet sizing die and gas checks. I did not get any of my friends reloading notes but since the reloading kit includes gas checks and bullet sizing die I assumed that he loaded it with a cast bullet and so I just going to carry on doing that.

 

[Johnny G1]

25-303 improved and dies are easy to get from RCBS when you send them 2-3 fired case's, poor man's 257 improved and is built on a P14 action with Timney trigger.

 

[mbogo3]

Homeland Security didn't seize them? C+H die and Tool has literally hundreds of dies in stock including wild cats.

 

[K223]

Makes sense. What brand are the dies? I’m just wondering who would be best to order from

 

[dan belisle]

Ken Waters did similar to save an old sporter Mauser he had. Will do anything a 338 Fed will do and a slight bit more. - dan

 

[mbogo3]

That one was a Rigby slant magazine mauser if I recall.

 

[dan belisle]

That one was a Rigby slant magazine mauser if I recall.

I believe so, fairly rare rifle. - dan

 

[mbogo3]

With a 200gr SP it would make a great bush rifle.

 

[rokoro]

Homeland Security didn't seize them? C+H die and Tool has literally hundreds of dies in stock including wild cats.

Dies are considered tools and are allowed to come to Canada by mail. I've ordered half a dozen sets of dies in the last couple years with no problem from CH4D and others

 

[mbogo3]

No I mean fired brass.

 

[K223]

That’s the plan with this one hopefully. Short barrel and heavy ammo because I’m skeptical of keeping decent accuracy at range

 

[Mystic Precision]

Give Ellwood Epps a shout. They may have reamers?

The 303Brit (and its wildcats) can shoot very well and with a quality barrel, likely MOA or better. There is nothing inherently wrong with milsurp actions.

Just keep pressures moderate if using a Lee.

Jerry

 

[davide montini]

In the future I’d like to build a 22-303 improve...a 25-303 improved and a 303 Epps...all in time ....
Hit up wise choice gunsmith ..he is the grand son of ellwoodepps

 

[Cantthinkofaname]

I could be sending you on a wild goose chase but I read somewhere (gunownerofcanada forum?) that there’s a gunsmith up in Whitehorse that has done tons of 375-303 conversions. So I committed the name “Bob’s Gunsmith and Precision Machining” to my memory. So you could harass them and see what they have to say.
As for sizing up brass. I had no problem moving 270win to 35 in increments. I have Sinclair neck sizing mandrels that work great. I don’t think you’d even have to do a between size. 0.311 to 0.338 isn’t that big of a jump.