For years Howa used all bottom metal for their floor plates/ trigger guards. The problem with that is Cast metal parts tend to vary in dimensions after cooling. Add to that using several stock suppliers with varying degrees of tolerances and it was a fitting headache at the factory. Later rifles went to all polymer on the bottom of the rifle not really because it was cheaper but because they could hold the polymer pieces to tighter specs making fitting much easier. Unfortunately, if you’re looking for the best accuracy the poly trigger guards mag wells do not hold even torque over time like steel or aluminum will. Some shooters with the polymer bottoms have had issues with the action screws cracking the polymer guards over time. There’s one company that offers all metal guards for the Howa but they are pricey and still require fitting to your stock.The floor plate is a very tight fit to the internal metal box magazine. I called LSI and they said that the fit can be a "son of a gun" and suggested a few methods including tapping it with a mallet. I did break the edges of the box magazine and it did help but still is not a straight drop in install.
I'm thinking of relieving the inlet in the floor plate where the box magazine touches. Another thought is to abandon the floor plate and get the replacable box magazine kit and call it a day.
Thanks and Happy New Year!