Kelson1066
Ultimate Member
Question for those with a lot more reloading experience than me.
I recently acquired a box of XTreme Bullets 9mm 147gr RN with a diameter of .357 during one of their sales. Using the Alliant Manual I put 4.0 grains of Unique in the case. I use the same load for my 147gr HP and 147gr RN both have a diameter of .355.
Yesterday when I was shooting at TMGN I observed signs of over pressure in the cases that were loaded with the .357 bullets. I could see the firing pin strike and a small rectangular dent around it (I'm using a Gen 3 G17). I know I will have to back off the load for safety reasons but my question to the group is:
With all things being equal why do I have over pressure with the .357 and not the others?
Google has not yielded results that satisfy my curiosity. Most answers direct me towards information about 9mm +P.
I recently acquired a box of XTreme Bullets 9mm 147gr RN with a diameter of .357 during one of their sales. Using the Alliant Manual I put 4.0 grains of Unique in the case. I use the same load for my 147gr HP and 147gr RN both have a diameter of .355.
Yesterday when I was shooting at TMGN I observed signs of over pressure in the cases that were loaded with the .357 bullets. I could see the firing pin strike and a small rectangular dent around it (I'm using a Gen 3 G17). I know I will have to back off the load for safety reasons but my question to the group is:
With all things being equal why do I have over pressure with the .357 and not the others?
Google has not yielded results that satisfy my curiosity. Most answers direct me towards information about 9mm +P.