It actually depends greatly on how you to it.
I have been working with this stuff for years, and have found that some people work with direct application of heat which does greatly weaken the plastic making it much more susceptible to shattering, while there are other methods, such as the hot water method, which heat the pipe much more slowly and cool it at the same rate making it much less likely to fracture. In addition, if you strapping tape the weapon well, it should be strong enough: PVC is always going to be susceptible to breaking, especially with the extremes that New England weather will put your weapons through, so the trick is just to be careful (and make spares).