Daryl
I believe shoulder structure has a lot to do with pressure build up from Lil'Gun. The 221 FB has a much more pronounced neck than my 218 Bee You can't seem to get too mcuh in a Bee to create a pressure issue but I can in the 221 FB, the K Hornet same compared to the 22 H, and the 17 HH has both a sharper neck and smaller bore. I really believe that the much higher pressures is the result of the sharp neck. In 410 and straight wall pistol cartridges you never hear of pressure issues or spikes etc. I have only heard it in bottleneck rifle cartridges. I may be completely wrong but the pattern seems to be very distinct to me.
|