The problem with the Madsen is that it is so darned expensive to find one. Like 700 or 800 bucks on gunbroker.
Mine cost $400 and that was a bargain.
If I needed a truck gun, a Mosin-Nagant carbine or cut down rifle would fill the bill. Impossible to destroy.
Yeah, you can get a new major brand rifle for $3-400. Easy enough to find a used on for $200
Yes, use a plentiful/robust/parts-available piece like a Mosin or a Russian-capture K98 (better still, a regular Winnie or Remmie or Sako) for a “working tool”. Leave a collector piece like this for display and special occasions.
I carried a Swiss K31 in my truck for years, It is a magnificent piece of machinery and dropped more than a few dear,
I also considered it useful if I ever needed materials to build a bridge out of or to drive across or build a cabin and it was great exercise carrying it
My truck gun for years was an old Norinco SKS stock condition with 10 rds in the magazine and nothing in the pipe. I kept it in a soft carrying case where I could just step out and unzip and pull it out or slide the whole case out and I kept 5 stripper clips loaded in the bag as well. I was out a whopping $100 for the rifle and $15 for case and ammo in it and I had 10 rounds of AK caliber ammo in semi-auto firing rifle ready to go.