My rule of thumb on used guns is not to pay more than 2/3 of new value, and that’s if the gun is in excellent condition. For MLs check out the barrel really well, if there is any signs of rust or pitting, shot the gun before you buy. Plus run a cleaning jag down the barrel with a clean dry patch. Go slowly with the patch looking for loose spots in the barrel. Loose spots can indicate a bulge in the barrel. The barrel can bulge if someone doesn’t fully seat a load, or if they double load. – Both are easy mistakes to make. Look at the patch when it comes out of the barrel – it should still be clean.

Otherwise if the gun checks out – get it if like it and the price is right.