Polymer is just part of the scientific name for plastic.
Plastic, by it's very nature will have problems somewhere down the line. Isn't Smith & Wesson having a problem with the dust shield warping out of shape after shooting awhile? At least I have read posts on it.
As a rep from Glock once enumerated...when a gun with a plastic frame costs more than $200, it becomes polymer. I personally cannot trust polymer completely when it is around 50,000 psi of pressure. That is just one reason why I don't own one. That doesn't keep you from enjoying them...I just don't think they will all be in working condition in a 100 or so years.
Saying that polymer is just another word for plastic is like saying steel is just another word for metal. Both are technically true statements.... and both are completely meaningless. Saying that something is made of "plastic" is exactly the same as saying that something is made of "metal".
Are you impressed with a gun made of "metal"? Uh, well, what kind of metal? You could make a gun out of mercury if you get it cold enough.
Same with plastic. What kind of plastic? The stuff they use to make legos.... or the "new" stuff? Stronger than steel, lighter than aluminum....
It's made of "plastic"... ok, is it....
Polymethyl methacrylate
Polytetrafluoroethylene
Polyetheretherketone (PEEK)
Polyetherimide
Phenolics
Urea-formaldehyde
Polypropylene (PP)
Polystyrene (PS)
High impact polystyrene (HIPS)
Acrylonitrile butadiene styrene (ABS)
Polyethylene terephthalate (PET)
Polyester (PES)
Polyamides (PA) (Nylons)
Poly(vinyl chloride) (PVC)
Polyurethanes (PU)
Polycarbonate (PC)
Polyvinylidene chloride (PVDC) (Saran)
Polyethylene (PE)
Or is it none of the above, one of the God only knows how many other varieties? I really wish people would stop saying "plastic" as if it tells you something about the strength or quality of an item.
I'm going to start referring to non-plastic guns as "metal", no matter if they're $50 pot-metal crap or stainless $2000 guns.
50,000psi? The plastic doesn't handle 50kpsi any more than the frame of a "metal" gun does. The barrel does ALL the pressure work. If the barrel fails then you're SOL, "plastic" or "metal".