|
Difficult opening of a break action firearm can be a sign that the cartridge that has been fired developed a higher pressure than the arm was designed to use. Check the pressure to which your gun has been proofed.
The Data sheet you've provided shows that the cartridges you've used develop a mean maximum pressure of 740 bar, (10,700+ psi, though the testing methods of the CIP differ somewhat from those of SAAMI). Many European shotguns are designed to use ammunition developing about 480 bar (7000 psi). (It may surprise some North American readers, but there is very little, if any, difference in the performance of shotgun ammunition to be gained through this increase in pressure).
Please, for your own safety, do not oil or grease the chambers. This will markedly increase breech thrust, that is, the cartridges will not, as they expand, secure themselves in place in the chambers. Rather, if used in oiled chambers, the cartridges will hammer the breechface- even in very strong guns this can lead to cracked actions and other problems.
Bob
|