Hmmm well I am just starting to make my own wildcat cartridge. You see I have this take off Mauser target barrel in 7.62x51 which of course gives me a .308 bore. The action is antique being an 1875 Martini made at the Enfield factory. The action was converted by Bonehills of Birmingham to .22 rimfire but some bodge artist somewhere along the line decided to drill out the liner and stamp .410 Shot on the barrel
but they did not undo the rimfire conversion. So when I obtained it if you did chamber a .410 shell you could see about 1/16" of the rim above the breechblock and so not surported by it:o.
Over the years I have gathered together the parts to rebuild the action into a working and safe centerfire rifle. It now has a .303 breechblock and a replacement lever with unadulteratded horns to lock the breechblock into battery
. and a .303 extractor. This last week I have put the action together and got it all working but without using the .303 extractor at this point as it has the bored out barrel fitted so still has the buthered rimfire extractor as that fits the barrel. Due to the Martini design I decided to stay with the .303 British parent case
this will shortened and have the body blown out to minimal taper and a sharp shoulder similar to Ackleys. The reason for shortening the cartridge is that my clubs range is only 75 meters and the Police have been giving me grief over the amount of full power .30 and .31 rifles I have. I will use their ignorance against them as with the improved case shape using 150 grain bullets it looks like in theory at least it might equal or even surpass the standard .303. According to the predictions thrown up by the computer programme either IMR 3031 or Vhit N135 are very promising powders. But being a shorter case as the Police here do not know much about these things a shorter case will appear to be less powerful and sound logical for using at the reduced range we have available. Also with no loading data available to them they cannot dispute my claims
Now as I am not wealthy
the maching work will done by myself including making the chambering reamer (a first for me) and the loading dies ( another first) before I can get to working on the barrel I have to first make a barrel vice and an action wrench. The steel is sorted out for the action wrench I just have to locate some for the barrel vice. Of course it helps that for some 25 years I worked as a machinist and that I have access to lathes and mills and a couple of grinders otherwise I would not be considering this project at all
Cases will be cut down to length in a split bush in the capstan and parted off and I am hoping that I can form the new neck and push the shoulder back without resorting to a set of forming dies. I have shortened and formed .303 brass into 6.5x53R in the past let's hope it goes as well.
This new cartridge fits into the wildcat idea perfectly as it's based upon another existing case and fits a special purpose for which to my knowledge no cartridge like it already exists.