as mm stated, the collet die sizes only the neck of the fired case. It does this by squeezing the neck down against a mandrel... no sliding action is done against the brass, so no lubrication is needed. You will need to have cases fired in your rifle for the collet die to work, since it only sizes the neck. If someone fires a cartridge in their rifle, and it's chamber is slightly larger than yours, and you neck size it, then chances are it will not chamber in your rifle. Full length sizing is good in a lot of ways, as you will take the brass back to "factory" dimensions, and they will chamber in any 270 rifle. Many people like to fl size for their hunting ammo, because it usually is a looser fit in the chamber, allowing for small amounts of debris, such as pocket lint, etc, to be on the cartridge and not lose your chambering ability. Disadvantages are the possibility of less accuracy (because of the loose fit), and reduced case life. If all you are loading is hunting/plinking ammo, I would probably opt for full length sizing. If maximum accuracy is your goal, and utter reliability in chambering isn't a high priority, then go with neck sizing. Either way, bottom line, is do what works best for you in your rifle.

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