09-25-2020, 01:07 AM
My x-ray vision failed me when I looked into the chamber to see what's going on while a round is being fired, sooo my understanding from the Zediker book is it's a combination thing over time, "pressure time curve, the relationship between bullet acceleration and pressure build up. A heavier bullet gets started slower, the pressure behind it is confined to build and peak is a shorter distance."
The amount of powder in the case matters, a 220 Swift barrel will erode faster than other smaller case barrels (.223 or 5.56) even if the peak chamber pressure was close to the same. A 220 Swift with heavier bullets should erode even faster.
"The erosion pattern follows the pt curve. The higher the pressure and the greater the amount of powder burned relative to bore size the greater the erosion. Erosion is increased by a higher volume of gas flow concentrated in a small area."
The amount of powder in the case matters, a 220 Swift barrel will erode faster than other smaller case barrels (.223 or 5.56) even if the peak chamber pressure was close to the same. A 220 Swift with heavier bullets should erode even faster.
"The erosion pattern follows the pt curve. The higher the pressure and the greater the amount of powder burned relative to bore size the greater the erosion. Erosion is increased by a higher volume of gas flow concentrated in a small area."