Question about Edgun Matador R5M Cal .25

Hi. I recently purchased an Edgun R5M in .25 cal. I am very satisfied with it. I am using it as it is shipped (I bought it in Lebanon so no limitation on fpe). So I did not do any modifications to it and I don't plan to. I have tried both Edgun Premium 25.4 grain pellets and Jsb exact king heavy MK2 33.95 grains. Both shoot very well. To be honest I'm looking for the pellet that provides more power (more fpe) so I'm assuming the 33.95 grain pellets are better for that purpose (I don't have a chronograph to measure speed). My question is: is one of the above pellets better in terms of not wearing out my gun. Is the rate of wear on the gun (o rings.. seals...etc...) related to the weight of the pellet? In other words, which is better for the longevity of my gun? Or maybe there is no difference.
Another question: is there a 'limit' to how heavy the pellets can be. I mean theoretically if I found a pellet in cal .25 that is extremely heavy (like 40+ grains), is it safe to shoot it in my R5M? Could certain pellets damage my gun? Can I shoot slugs through it? In other words, can I safely (with no negative effects on the gun) shoot any pellet or slug that fits in the magazine, regardless of weight?
I really appreciate any info you can give me. Thank you.
 
Neither pellet will wear the gun any faster. The limit on weight is more about what the regulator will support, and what trade-offs you are willing to make for weight v. speed. I haven't had my R3 out for quite a while, but IIRC, you should be o.k. with anything that fits in the magazine. You can shoot slugs, the question will be how well they shoot; I have have heard mixed results with the R3, so my suggestion would be to get some samples and see how they shoot. If you haven't already, you should read up on how to adjust/optimize the regulator because different pellets/slugs will require adjustments to get best results. Have fun!
 
Thank you for your reply. I read somewhere that slugs need a special barrel and that the 'chamber' has to be big enough or something like that. How can one tell if a certain pcp is equipped properly for shooting slugs? Try and if they shoot accurately then I'm fine? Could a certain slug damage anything in my pcp gun if the gun was not designed for that slug? Or will it just not shoot well but cause damage? I would really appreciate any input from anyone who has the know how and experience with pcp rifles. Thank you.