Perhaps some folks may think the term "disaster" in the subject line to be somewhat over-dramatic, but what else would best describe the destruction of a spring gun's maninspring, spring guide, and piston seal, as well as leaving the gun impossible to #### due to the aforementioned damage?
The pic below is the remains of the mainspring removed from a Diana Model 52 that was purchased new only a few months ago. As can be seen, it has been broken into five distinct pieces, and has broken at both ends. In addition, there are several fractures that have not yet broken all the way through, but if they had, that spring would be in at least eight pieces. The spring guide was broken into several pieces, and the piston seal was burned black as coal. Certainly not the degree of damage that one would expect to find in an airgun only a few months old, and from a reputable manufacturer.
I had my suspicions of what had caused the damage, so when I called the owner to inform him of what I had found, I asked him specifically, what pellets he was using. The answer came as no surprise to me - the gun had been fed a steady diet of Skenco Poly Match pellets, and Gamo Raptor pellets, weighing in at 4.0 grains, and 5.4 grains respectively. When I asked him why on earth he would use such light pellets in a magnum class springer, he told me that they were recommended by the retailer, as well as his own on-line (forum) buddies.
I proceeded to tell him that he had been badly misinformed, and went on to explain the reason that these light pellets had caused the damage that they did. I recommended that at least 10 - 10.5 grain pellets should be used from this point forward.
I have always found the Diana 48/52 rifles to be a bit harsh with regard to firing cycle, so I cannot begin to imagine just how nasty firing a 4.0 grain pellet must have been. It had to have rattled the shooters teeth. During the course of test firing the repaired rifle, I set the 10.5 grain CPH pellets aside, and tried a couple of 8.4 grain RWS SuperDomes. The increase in report and harshness was astounding.
The 8.4 grain SuperDomes chronied at 1070 FPS, so I cannot imagine what the 4.0 grain Skenco pellets would have registered.
The 10.5 grain CPH pellets chronied at 960 FPS, and resulted in a much more comfortable shot cycle.
The pic below is the remains of the mainspring removed from a Diana Model 52 that was purchased new only a few months ago. As can be seen, it has been broken into five distinct pieces, and has broken at both ends. In addition, there are several fractures that have not yet broken all the way through, but if they had, that spring would be in at least eight pieces. The spring guide was broken into several pieces, and the piston seal was burned black as coal. Certainly not the degree of damage that one would expect to find in an airgun only a few months old, and from a reputable manufacturer.
I had my suspicions of what had caused the damage, so when I called the owner to inform him of what I had found, I asked him specifically, what pellets he was using. The answer came as no surprise to me - the gun had been fed a steady diet of Skenco Poly Match pellets, and Gamo Raptor pellets, weighing in at 4.0 grains, and 5.4 grains respectively. When I asked him why on earth he would use such light pellets in a magnum class springer, he told me that they were recommended by the retailer, as well as his own on-line (forum) buddies.
I proceeded to tell him that he had been badly misinformed, and went on to explain the reason that these light pellets had caused the damage that they did. I recommended that at least 10 - 10.5 grain pellets should be used from this point forward.
I have always found the Diana 48/52 rifles to be a bit harsh with regard to firing cycle, so I cannot begin to imagine just how nasty firing a 4.0 grain pellet must have been. It had to have rattled the shooters teeth. During the course of test firing the repaired rifle, I set the 10.5 grain CPH pellets aside, and tried a couple of 8.4 grain RWS SuperDomes. The increase in report and harshness was astounding.
The 8.4 grain SuperDomes chronied at 1070 FPS, so I cannot imagine what the 4.0 grain Skenco pellets would have registered.
The 10.5 grain CPH pellets chronied at 960 FPS, and resulted in a much more comfortable shot cycle.
...and keeping the pellets subsonic for accuracy/stability? 
