Ask Starline—From the FAQs on their website:
On sizing:
“Generally speaking, Starline cases require no resizing prior to loading. Due to variances in diameter of different bullet types, it is a good practice to size the case only as far down as the bullet seating depth. When full length sizing is required, it will be noted in the box with the brass. The only Starline cases requiring full length sizing prior to loading are the .454 Casull, .458 SOCOM, and sometimes the .45 Colt(Depending on the bullet diameter to be used).”
On trimming handgun brass:
“Trim-to-lengths given in most manuals often confuse people if they are unsure of their actual purpose. Most manuals generate their own trim-to-lengths from SAAMI maximum cartridge drawings. They usually pick a number just below the SAAMI maximum and state this as the recommended trim-to-length. Depending on specific caliber, some cases will shrink and others will grow when fired and reloaded. The trim-to-length is trying to say: "If case is longer than trim-to-length, then trim back to this." The confusion comes in when people purchase new brass and want to trim it back to trim-to-length stated in the manual. One must understand that a manufacturer will not produce cases at maximum length and that we as manufacturers must have a reasonable tolerance to work with. Most people do not wish to trim brass, so at Starline, Inc., we operate a tolerance of .005 below SAAMI maximum and that window ranges from .003 to .010 below, depending on the caliber. All auto-feeding cartridges are held within .004, and revolver normally is within .005.
“The trim-to-length we recommend for peak performance is a variation of no more than .005 and length within .010 of published trim-to-lengths, but never exceeding trim-to-lengths.
“Remember, consistency in length relating to consistent crimp is more important than all cases being the same length as the trim-to-length in manuals, assuming it is not too long.”
