300 win mag case length

2.620
Trim to 2.61

I agree. SAAMI specifications are 2.620, +0.000, -0.020. Normal practice is to target the middle of the tolerance range, which is 2.610" Some will go longer so they are 0.005" short of the chamber length, if they have good measurements on their chamber.
 
As indicated 2.62" is nominal max case length for the 300 WM, however every chamber I have measured or had reamers ground for allow another .010-.015" beyond nominal max case length just for safety reasons.
 
As indicated 2.62" is nominal max case length for the 300 WM, however every chamber I have measured or had reamers ground for allow another .010-.015" beyond nominal max case length just for safety reasons.

I have noted this with most factory chambers. I have cast a number of them, and they seem to tend to allow some extra leeway.
Good thing, too. I have had factory ammo that was well over SAAMI max on the first firing.
Dave.
 
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