I have a sporterized patern 14 enfield in .303 british I want to wildcat. My 1st thought was the .303 epps. However on further examination I have begun to think strangely. How about someting a bit longer? What brass would I use to extend the length of the 303 case? Another thought was the .303-7mm rm. I have already replaced the .303 magazine box with a 1917 springfeild box and reformed the feed ramp so my case length is......well, longer. Please feel free to add your comments.

45otto,
On page 5 of gunsmithing I asked a similar question under "jeffe how big can I go with a p14". The answers will speak volumes.

With the P-14 go hog wild!!!!! Why not rebarrel and open up the bolt face a bit and go with the .416 Rigby or the .366DGW?

How about running a 300WinMag reamer into it and then shooting it until the barrel goes. A 300WinMag using .311 projectiles will be fun.
Cheers...
Con

Now that's what I'm talking about. Can the reaming job be done by hand with any amount of reliable results.

Judson, quite nice! Where did you get the hinged floorplate?

45otto,
Search this forum for "311 Win Mag". My P14 is in 303/25 but will most likely become a 303-35 in the future.
Cheers...
Con

I copied this from another post on this site:

Here are a few concerns, however:

1. Most .300 Winchester reamers cut a chamber neck that is perfect for a .308 bullet. The neck is a little tight when you put the slightly fatter .311-.312 bullet in there. One alternative is to use a neck reamer and simply cut the neck portion a little bigger. Another option is to turn down the necks of your brass by .003 inch, which is what I chose to do.

2. The original box for the .303 is too short to accommodate the longer cartridge as it is. You can have your gunsmith cut off the front and back of the magazine box. If you've seen that box, you know what I mean. There is over 1/2 an inch of space that is wasted in that box because of the huge metal "plugs" that form the front and back of that magazine. It is possible to weld in a new front and back which should lengthen the box a great deal.

3. Another magazine option is simply to substitute a 1917 Enfield box for the box in the '14. Remember, that 1917 box was able to accommodate a .30-06, and I've had no problems fitting a .300 Winchester cartridge that measures 3.370 into my '17. Another option is to call up Gun Parts Corporation of New York and order one of their "Magnum" boxes for the P-14/17 action. This will require a bit of milling on the receiver, but it is not a major job by any means. I also find their "cock-on-opening" conversion is excellent.

4. I think the feed rails on the P-14 are fine for a .300 Winchester case. Remember, the rim size on the .303 is virtually identical to the .300 Winchester. In fact, Lee uses the same #5 shell holder for both the .303 and the .300 Winchester Magnum.

5. Most P-14s were made with bores that measure at least .312 inch. Hornady is the only U.S. manufacturer who makes .312 bullets, and I've found that they tend to be more accurate than Sierras, which are .311, but others have had opposite results. All I know is that I've had outstanding results with the Hornady 150-grain spirepoint. I back the load off to about 71 grains of VV N160 with that bullet and get a velocity of about 2980 fps. I could easily stuff about 5 or 6 grains more to speed it up to full .300 Winchester velocities, but this load is so accurate for me (1.5-inch 5-shot groups at 200 metres [220 yards]) that I don't bother. I find that the case life with this reduced load is fantastic.

6. I tried this rifle both with and without forend support for the barrel. As a .303 British, this skinny little barrel was fine free-floated. However, as a .303 Magnum it definitely needs a bit of support near the forend. I put some bedding compound there and padded it with a layer of electrician's tape. It works great. Obviously, you should bed the rest of the action in the conventional way.

7. When seating bullets, remember that the bullet is fatter than a .308. This means that it will actually engage the rifling sooner than a .308 bullet would in a conventional .300 Winchester Magnum barrel. I've found that 3.360 inches is about perfect with that Hornady 150-grain bullet. You will find it a bit tricky seating the bullet because you can't set the seating die to stop in the same way that you can with a .308 bullet, which is what this die is originally designed for. It's all a matter of "feel". Try it, and you'll instantly understand what I'm saying.

8. Depending upon the condition of your barrel, you'll find that accuracy drops off pretty quickly. My barrel is not too bad -- but, lets face it, 1914 was a long time ago and they used to use corrosive ammunition in those days. I use moly-coated bullets, but even then I have to clean the barrel with a bore snake after about 8 shots. For hunting it would be fine, just don't try to shoot long strings off the bench with it without cool down and cleaning.

9. When the barrel finally does give up the ghost, don't despair. You can either order another barrel in .303 from companies like Shilen or Douglas, or you can get a new barrel in another caliber and make, for example, a 7mm Remington Magnum, .300 Winchester/ Weatherby/ Holland & Holland Magnum, 338 Winchester, .375 Holland & Holland, etc.

10. Finally check out Boyds for inexpensive stock options. They make a number of stocks for this action.

Good luck and good shooting!

I made the drop mag on my P-14 and as to the 300 Win with the .303 bore your best bet would be to use a 300 Win. mag reamer with the 303 pilot. Then cut your neck and throat with a 303 neck and throat reamer.