I have seen threads upon threads and images of your work sir and i have no doubt you could install the DBM. Quick background on myself, i am an engineer and i design/fabricate prototype and production automated machinery for a living , while working on firearms as a hobby. I dont have much spare time so the fact of a drop in bottom metal caught my attention(Lazy/cheap on my part maybe, or maybe just hopeful). If it is totally inconceivable for me to think that a part marketed as drop in should actually drop in, then maybe i was wrong in everything I said. If i should have known better, due to the tolerances and significant design differences encountered in all possible scenarios that the bottom metal could be used in, that would render the "drop in" more of a fools gold than reality, then maybe i am just to slow for this high speed stuff. Until i finally learn to assume, that if it sounds to good to be true it probably is, i will just keep reading product descriptions and buying into the fantasy of which they are made.
Noted, and you "should" have a point.
Now here's reality:
You have an infinite number of guys working in this trade at all levels. This industry has historically been a cottage one. Just what is an M700 footprint floormetal? If you call Remington and ask for a print, they'll laugh and the last sound you'll hear is the click signalling the end of the conversation.
The ghist is there is NO standard. Any attempt to regulate and make one will be answered with fierce opposition because then we ALL have to run to a standard.
I'll use something as innocuous looking as a recoil lug for example.
If it's 5/16 it should be .3125" right? Lets toss in a tolerance just cause it deserves one. Let's say +.0025/-0.0"
Now go buy a dozen of the most popular recoil lugs and measure them. It's from .290" to .315" or more.
Why? Cause a guy fuggered up in his little shop cause he didn't wait for the machine to warm up, didn't use the right grade of tool, had the coolant too thin to save money, wheel runout on the grinder, heat treater cooked em too much, yada, yada.
Still works though right? So, what the hell, lets sell em cause it don't matter anyway. We have to measure everything cause the actions themselves are often all over the place.
This is the world we all exist in with firearms.
There's long winded debates over AI's being able to thread and chamber without the action. Many are advocates for it. I personally am not for the above reason. Alls it takes is one bad day in the QC and a guy is picking gun parts from his face.
So, back to your floormetal debackle. If you look at the legacy of M700 floormetals you see evolution before you. They change stuff on the fly and it's the next best thing. -Just ask them, they'll tell ya'.
If you really want to go off the deep end, buy some Savages and get your mood stabilizer prescription refilled cause it's gonna be FUN! (yay!) Action screws are all over (even within the same legacy). Why you think they run the barrel nut? Cause then it don't matter! It's so bad that guys like Tom Manners is literally to the point of having an aneurysm because of all the guys calling and bitching because their "drop in" stock don't work with their shiny new Savage action. Tom's stuff is jonny on the spot. Savage's production facility is like lightening; it never strikes twice in the same spot.
So, Dave (PTG) made a DBM based on a particular stock and a particular pattern of floormetal. In THAT moment it probably fit just fine. How many crossbreeds and mixed chromosomes of M700's have their been since? Remington couldn't even tell you if you asked.
We all just "do". There isn't much of a plan.
It's not until you get into the actual MIL SPEC level that stuff has to run to a standard. I've been through the FN machine gun armorer courses. There they actually DO have to maintain a toelrance. The Gov inspector will take the latest LOT of M249's, shootem, then rip them all down to level 3 echelon service and toss the parts in a pile.
Then assemble all the guns again. They ALL must run to standard. If they don't then entire batch is scrapped until it does.
The need for this is obvious as combat demands that guns work all the time and parts are interchangeable.
If only bolt guns were the same....(what fun would that be though?)
Hope this helps.
C.