Quote Originally Posted by LongRange View Post
and so we are clear by 0.020 past the neck/shoulder junction i mean the bullet seated deeper by 0.020 past.
So I got my shipment of 168gr Hybrids so I could take some measurements. Based on discussions here, I will set my dummy round up to be seated 1-caliber length (.300) into the neck plus 0.020" to allow for erosion. At this length, the ogive of my bullet should be approximately 0.030" from the lands.

Based on these parameters I have the following choice to make:

  • If I use 175 SMK as my dummy rounds (most commonly used) then the 168gr Hybrid will be seated approximately 0.100" deeper than ideal with an COAL of approximate 2.695" (0.116" shorter than SAMI max and 0.206" shorter than mag length)
  • If I use 168 Hybrid as my dummy rounds then the 175 SMK will be seated approximately 0.100" shallower than ideal with an COAL of approximate 2.852" (0.042" longer than SAMI max and 0.049" shorter than mag length)


If I set for the 168 Hybrid then the 175 SMK would be seated with the bearing surface contacting 0.224" which may be reduced to 0.194" as the throat erodes. Seems to me like that might be getting seated a little shallow and maybe I am better off just living with the fact that if/when I use the 168 Hybrids they will be seated a little deep which would decrease case volume (i.e. increase pressure) and I may be giving up a little velocity. Thoughts?