A little different cartridge but same powder, powder weight and bullet.
338 RUM 300 SMK 101gr US-869. 2732FPS w/26" Sporter Barrel SD= 0 ES=2 COL=3.818" Length from Base to Ogive = 3.017"
No pressure signs whatever except a strong desire to FL resize after a few shot through a case. I am satisfied w/the velocity and accuracy to leave things there.
Your chamber and barrel may be affecting things also for comparison purposes. I'm assuming both are custom which is a complete different situation than my factory chamber and barrel. However, I did to a Tubbs Final Finnish procedure on it when new.
The greater the case volume the lower the pressure and the slower the MV. The difference between FL sizing and Neck Sizing in the above load is a reduction of 17 FPS for the neck sized shots. The same should hold true in your rifle even if the bullet was seated into the rifling.
Your rifle, if sporting a longer barrel, should achieve another 100 to 150 FPS over the RUM. At 101/102 grains and the 300 SMK you're just loafing along, I'd think.
Originally Posted by crittergitter
338/ 300 Ultra + 101 grains US869 + Federal 215 + 300 smk (3.830 OAL)= extractor mark.
338/ 300 Ultra + 102 grains US869 + Federal 215 + 300 smk (3.930 OAL)= no pressure signs.
It appears that seating a little deeper makes a lot of pressure difference. Is this consistent with anyone else's experiences? Is there another variable I may be overlooking? These were both 3 shot groups with Remington brass. One round was fired with 102 grains in the first series and it left a shiny, but not raised extractor mark.