Take a look at the L.E. Wilson trimmer system. This is an old system, in that it has been in production for 50-60 years, and is one of the best. The trimmer is VERY SIMPLE and is dead on accurate. So much so, that many dedicated target shooters use this system exclusively, including Bench Rest shooters. What is unique to this system is that the shell is held by the body and not the head as on all other trimmers. You need a "shell holder" for each shell The shell holder looks like a short piece of barrel chamber that is cut so that about 1/2" of both ends of the case showing. You then hand hold the holder in the trimmer and trim away. What makes the trimmer so accurate is that on most rifles the bolt/breech face is not exactly 90 degrees to the bore of the barrel. As a result, the case head of a fired case is rarely in line with the bore. That's why when you use a trimmer that holds the case by the head you usually have to use some sort on an alignment pin in the case throat to center the case. It's a good system, just not as accurate as the Wilson. The body of the case IS in line with the barrel resulting in a better alignment with the trimmer. The shell holders are cheap, about $6-7 from Midway. You don't need a different shell holder for all cases. Any shell in a "Family" of cases will use the same shell holder, I.E. 30-06, 25-06, .270, 280 , or 250 Savage, 300 Savage, 22-250, etc. The Wilson trimmer also has primmer pocket reamers and inside neck reamers for use in the trimmer. It's a great system and, if I'm not mistaken, cheaper than many other trimmers, including shell holders.