Hi Guys, I've been reloading for my new .270Win for a short while now and get acceptable groups from the bench over 100m. Last week I obtained a RBCS precision mic to determine my rifles headspace. The mic. works on the principle of measuring fired brass from your rifle (thus fire-formed in your chamber) which closely (approx. -0.002') resembles your chamber size.. The manual also supplies the ANSI min and max. values for a specific cartrigde (refering to the length from the head of the case to a datum point on the shoulder). I'm not sure as I don't have the manual with me now, but I think the tolerances are min: 2.0487' ; max: 2.0587' for the .270Win. The "zero" reading on the mic refer to the minimum ANSI spec. nl. 2.0487' Now for my problem: Fired Brass from my rifle gives a measurement of -0.0025' (avg. of 25 fired cases measured). This equals 2.0487' - 0.0025' = 2.0462' , which is below the ANSI min. value. Even if I allow 0.002' for the "springback" effect of the cases, this still means that my chamber is slightly too small. Handbooks suggested that I should resize to 0.001' - 0.002' more than the actual headspace (2.048'), but when I set my full length resizing die (hornady) to max (shell holder touching the base of the resizing die) these cases grew in lenght by 0.004' to +0.002' (measurement in the precision mic was now 2.051') Although these rounds do chamber in my rifle, a little bit of force is need too close the bolt. Should I : 1) Only neck size? 2) take a few thousands of an inch off the base of the full lenght resizing die, to allow the case to move "deeper" into the die in order to set the shoulder back to -0.002' off the headspace? 3) Have the chamber of my rifle enlarged by a few thou of an inch? 4) Just continue reloading as current ( thus, will this slightly oversized cases for my chamber influence my accuracy/safety?) Hope you can give some advise. Appreciated!