Originally Posted by Tikkamike
I want a cartrige short enough to fit in the magazine if my chamber is throated to seat the bullets out a bit
'IF' should never be used with a 'custom build'.
The concept starts with ballistic research, and a rational assessment of your needs.
But an actual build starts with the bullet. Buy them, buy the brass and dies, and work out any system bugs with dummy rounds.
Measure & fill out a reamer print with the dimensions, clearances and throat desired, and buy a finish reamer FOR YOURSELF.
You can buy all parts and deliver to a gunbuilder. Speekin of, finding a good gunbuilder -who isn't a liar, can be the toughest part in a build. I've yet to find one....
Damn good luck to ya