The main reason for the 6.5 Creedmore is its ability to work through a short action and still have the bullet seated long whereas the .260 Rem has a hard time doing this. Put the .260 Rem into a long action and problem goes away. Its all a matter of what action your wishing to build on.
I see what your talking about and agree, but I changed directions a few years ago to avoid
all of the issues with mag length and bullets seated long and found that with proper chambering
and standard bullet seating, an extended mag was not nessary in order to get good velocity
and accuracy.
Most of the new High pressure/velocity cartriges have lots of free bore and in order to make
them shoot well some changes in philosophy was nessary.
I no longer design/build rifles around a certain bullet,special seating depth,extended magazine,
special neck diameter and other special things. and have found that the standard cartriges can be
made to shoot extremely accurate.
I'm not trying to talk anyone out of doing any of these things , just saying that with all of the
new components and tools for reloading that are available we no longer have to modify cartriges
in order to make them shoot well.
If a person wants velocity, case capacity is the way to get it. seating the bullets long does not
increase case capacity as much as simply going to a larger case seated to the standard mag
length.
When trying to get the "Most" out of a case an extended mag will help but only if there are special needs.
Not trying to start an argument just trying to offer some options to the original poster who stated
that he was not impressed with the shorter cases (Apparently he would like a little more velocity).
In a short action.
J E CUSTOM