Hello, everyone. I am new here, but as far as wildcats go..have a dbl. set trigger Mauser .219 Donaldson Wasp sporter built by Bob Womack jr. around late 40's.
Now this next ctg. isn't a wildcat..but it has me puzzled. I picked up a nice conditioned WJ Jeffery rook rifle in .255 Jeffery. Gun appears not to have been used much. Bore is ex. with a .250 groove dia.
I had altered an RCBS .25-20 WCF. neck-sizer die, by facing off .150 from end with ceramic tooling,& re-cutting chamfer..polished everything back up.
The first thing I did was copy the dimensions given in Donnelley's ctg. conversion book..this little ctg. fit perfect.
Then, on a whim, I wondered how far an unaltered .25-20ctg. would chamber. To my surprise, it chambered all but about 1/4".
Backing sizer die out, I carefully threaded die downward, sizing & checking case for fit.
It fully chambered with shoulder dimension..measured from ctg. head, a full .100 longer than Donnelley's book stated. Whats more, a full length case fits..Donnelley says trim about .150 from original.
Now the first thing someone would say is..a .25-20 WCF. reamer was run in there..but the shoulder still needs to be pushed back.
Just wondering if their tolerances wern't real tight at the time. At any rate, it makes case forming easier!
I haven't got a chance to try it out yet..Oh twist is 1 in 13 3/4". These are neat little rifles!

A chamber cast would be the best way to see what is really going on there.
Maybe it just has some freebore before the rifling tightens in.
Would love to see some pictures.