So, question. I have searched these forums, googled, etc. and either missed or could not find an answer. Has anyone taken the .404 Jeffrey, necked it down to .416 without changing anything else? I know there is not a lot of difference in diameter between parent cartridge and this wildcat idea, but I have approx. 1000 .416 bullets with nothing to use them in. I have owned a Rigby, and Remington .416's and just want something to be different. I like the shape of the .404 case, and a friend's rifle in .404 was one of the slickest feeding rifles I have ever shot. Also I prefer the standard 98 Mauser action, or possible a 03 Springfield since I have a few of each. Any help would be appreciated. Thanks in advance.

.404-.416 US Jeffery Wildcat / .416-.404 American Wildcat
http://www.municion.org/404/40...UsJefferyWildcat.htm

.416 Tatanka
http://www.municion.org/41/416Tatanka.htm
https://ammoguide.com/cgi-bin/...LFkQPVuROf&catid=249

416 Accurate Reloading -- after the round about path that the RUM is (loosely) based on the 404 case .. and i have one on a 1903, and have built all of the accrel carts on mausers ...

info in my signature

I don't have much to add to Jeffeosso. His AccRel line is impressive, especially the Rigby-based 500 (which should use the 0.255" freebore rather than the original reamer's 1.25" freebore).

My comment is only to double-think what you will be doing before 'buyer's remorse' could hit you. A wildcat would seem an expensive way to use up a lot of bullets. some may think the Jeffries' neck is about 1/4" too long and the cartridge requires magnum-length actions, to boot.

I've owned several 416 Rigbys and enjoy handloading to use the capacity.
However, my next 416 will probably go the simple route: 416 Ruger out of a box. It fits in a standard action and in a 7.8--8.0 pound Ruger Hawkeye rifle.

Jeff's 416 AccRel has 6-grains more capacity than a 416Ruger, which is not a lot at the 100-grain capacity level, maybe offering 35 fps over the Ruger in equal situations. For a significant ballistic jump you should probably look for 15-30 grains more capacity, which would put you into a full "416 RUM-wildcat" or a handloaded "416 Rigby", back where you started, possibly with hotter loads.

yeppers -- the 416 accrel was obviated by the 416 ruger -- no real difference ---

of course the accrel and ruger are both more modern case designs than the taper of the Jeffery's

and HECK YEAH, the 500Accrel should have been short throated for everything but special cases where one wants to shoot bmg bullets --- i SHOULD have done it that way ..

but, again, interesting round-about story related to this OP --- i have more than a couple milsurp bullets, doing nothing ... which lead to this folly

Thanks for the opinions and information. Just an idea I have had kicking around. The first post about the .404-.416 is exactly what I envisioned. I have several projects going right now, but who knows. Again many thanks for the answers. This forum is the absolute best!

yeppers.. we are full of sh.....opinions around here ...

the 416 tatanka, as mentioned by Jgrabow6493, has it own tales of woe, due to mismatch in reamer prints of the 404 .. so make sure you order a die reamer from the same dude as the chamber reamer

i do not think a full length 404 on a 1903 would work out ... the receivers are hard as my head, BUT mauser bottom metals can be made to work, just requires a little tinkering ... the problem is there just aint much room in the back of a springfield (my favorite action, or at least tied with, the mexican mauser) to make it happen, and hogging out the front is always anti-fun for feeding issues

Just get some rolling papers and paper patch some 416s in a 423 barrel.

Little off the subject but I built a 450-416 double rifle with the help of Rick Stickley, and it worked good of course, but sold it but had two sets of dies and still have one set (RCBS Customs) if anyone is interested, Id sell them cheap..