I have a slow gun , a Ruger 7x57 , that you can not get enough 4350 in the case to show pressure........It has a huge chamber , a Loose bore and a mile and half of throat...... Sometimes a slow gun is just gonna be slow. Look for usable accuracy and decent usable velocity, not the velocity someone else tells you there gun gets....
also have a super fast gun , a .260 and with Reloder 17 most people would be eating gun parts to keep up else you knew it had a 30 " barrel Throated a little longer then most.