My R1 was bought in 1984. Then the R1 was advertised at 930fps.In October 2013, after 275,000 rounds it was shooting CPL at 890fps.I put in a new factory spring, piston seal, breech seal.It shot 850.I should have left well enough alone.Recently I put in a VORTEK kit (Motorhead did).CPL at 1050fps.CPH Heavies (10.5) at 890.The average German air rifle shooter of an HW80 or FWB124 will probably only shoot 1500-2000 pellets in their lifetime. British shooters, a bit more.Spring change is not an issue.IMHO a well maintained spring should last a lifetime or two.
Well really when you think about it it is just a spring.You take a valve spring on a 4 banger cruising at 3000 rpm and its getting exercised 750 times per minute.