New to the glock 20,was wondering on when do you have to change the recoil spring.Will shooting loads around 1250 be ok.If so what poundage is good for hotter loads say 1300-1400.
All of my multi thousand round spring experience has been with Gen 3's. Replacing that single captured spring every 2500 rounds is often enough. Don't really know about the Gen 4's but suspect the same schedule would apply.
As far as upgrading to a heavier spring I know it is most often done on Gen 3 or earlier G20's. I went from the 17 lb OEM spring to a 20 lb non captured spring on my Gen 3 G20's and was pretty happy though I don't shoot nuclear loads that might require more spring. Wolfe sells spring sets so you can try different spring weights and adjust to your needs. I am told the Gen 4 Glock 20's (captured dual spring) don't see much need for aftermarket springs... but my personal experience on that is zero. However... my G40 (Gen 4 G20 spring) is plenty of spring for every load I have ever shot. No doubt the extra slide weight has something to do with it too.
My mantra is "change springs to solve issues", which predicates that you must first have issues before altering the spring weights. In order to advise on altered spring rates, the issue(s) would have to be declared. If you aren't having issues, carry on.
As far as longevity, 2500 rounds would be an aggressive, but not unreasonable schedule. I would consider it a lower limit. Upper limit I would say is 5000 rounds.
^^^this. Unless you are having issues ... FTF, stove pipe, etc. ... do a return to battery check. If the RSA will RTB, no need to change springs.
I've found the stock OEM RSA is good to about 250 PF ... that is a 200 grain bullet at 1250 fps muzzle velocity. Above a PF=250 you may need a 22# or 24# RSA to prevent slide-frame slam.