Looking at the magpul bottom plastic to switch over from a BDL bottom metal assembly to their detachable mag.
What's involved with buying, and switching out ?
In letting, bedding it in ?

Data point of one - and I didn’t spend a lot of time on the project.

The Magpul package comes with the trigger guard / well, and one magazine. The trigger guard is slightly oversized, the magazine release paddle is metal, and seems to work well for me.

I looked at adding one to a short action BDL - it was not a drop in as I had expected. I would have had to inlet the stock and trim the ends of the Magpul guard/well to get it in, and it appeared that I may have to open up the sides of the magazine box as well. I’m pretty certain the factory receiver bolts would have worked, and I don’t recall the Magpul package including any bolts.

The BDL metal was working, so I didn’t go any further.

My opinion - they are set up to drop in the Magpul stocks, and can modified for BDLs, but are not a drop in.

I did one in a Bell and Carlson bedding block stock and it wasn’t to bad just go slow with a dremel and it goes fine. You will have to grind out some of the magwell area as well as inlet for the bottom metal itself.

What I did was I let everything and then bedded it all in there and it turned out well.

Was wonder how it would fit with a factory sa dbm stock.
I took an sps stock, and made it into a dbm stock.
Had to elongate the bm area, and widen where the mag box area went up in.
What I'm thinking is to convert my factory dbm, over to the magpul . I know I'll have finger tab inlets still, where you grab on the sides to pull the mag out, but may be a cheap, not so rattling system.