I asked about this question in another thread earlier in sept. but I wasn't able to follow up on it and see what anyone had to say. The question is, what kind of service life does the hk polymer have and what kinds of chemicals would attack this plastic. I've been using birchwood casey's synthetic gun cleaner, the aerosol based one. Some solvents and cleaning chemicals have warnings about certain kinds of plastics. A friend used the regular birchwood spray on another firearm and it attacked a crinkle finish on the gun very badly and removed a good deal of it in the process. Does anyone have an experience with a certain product attacking the hk polymers? My prior question is in regards to the plastic's durability/lifespan..you VP70 owners may be able to give better insight on this question since the guns are all pushing 30 years of age now, how are they holding up? In my profession I use various polymer-plastic parts like pulleys and valve shroud bodies etc. and while I'm fully aware of the strengths of fiber impregnated polymers I have seen these parts shattered under beyond-human-strength stresses and while I'm confident a human grip won't break a usp frame, I wanted to know what possible reactions the plastic could have with exposure to like UV radiation over prolonged periods of time, or certain solvents which could in turn compromise the plastic's integrity. Some plastics I work with will crumble and dry-rot when exposed to UV, others will warp and melt when exposed to certain chemicals. SO, that being the case, does anyone have any insight or experience with the USP/p2000 polymers in those regards?