Every since the Magpul MOE handguards came out we saw a huge decline in sales of the metal quad rail systems.   The Magpul MOE accessories really was a major changing in the way accessories are added to an AR15 or other firearm like an Remington 870 or whatever else Magpul Inc is making.   There are plenty of reasons to keep your rail system on you gun because I’ve recently witnessed some “rate of fire” tests where many plastic accessories just burnt right up so always know the operating limits of any firearm alteration.

Even though sometimes the cost of buying another complete AR15 Firearm vs just buying  AR15 Complete Upper Receivers might only be a few hundred dollars, if you are thinking about stripping down your enter upper receiver think about the cost of all of the parts you are removing and if they are re-sellable or not.   I would suggest thinking about buying another upper receiver and if you like it a lot, then consider buying a lower receiver for it later to complete the 2nd firearm. Its a much better idea then regretting selling off a firearm.