The following explanation was verified by the son of a WWII Russian Veteran. His father told him that they were trained to operate their Mosins as follows:

- These rifles were usually used from some sort of rest and, many times, from a "dug-in" position or trench;
- Therefore, when "dug-in" the straight bolt was to be used with the LEFT HAND, over the top;
- This allowed the soldier to stay on target and to cycle the bolt with less movement;
- It also gave the soldier MORE LEVERAGE.

Try it! Heel of your left hand on the left side of the receiver, palm over the top. Now, wrap your fingers around the bolt knob and rotate your wrist counter-clockwise. It snaps right open. Very, very easy to do.

In fact, I can cycle the bolt in this manner, on most of my straight bolt rifles, WITHOUT even touching the rifle with my right hand at all: rifle laying across my lap; muzzle pointed to the left.

I actually learned this on my own, while at the shooting range.

I found that I never had to take my eyes off of the target and never had to change my righthand grip (righthanded shooter). This allowed me to be more consistent in my shooting and achieve better groups.

It was completely by accident. I was wondering how lefthanded people would cycle the bolt (It just happened to be an M39Finn! ) and I reached across the top of the receiver with my left hand. I thought, "Man, that was pretty easy." Then I started playing around and praticing with it and decided, that this had to be intentional. It made too much sense and was too easy/practical to be otherwise.

Later on, I was talking about this on one of the forums, and I got an email from a guy that claimed to be an immigrant son of a Russian WWII Veteran. He verified that it was, indeed, intentional, and that his father had told him that they were taught to operate the bolts that way when they were in a "dug-in" or "entrenched" situation. Wish I could remember the guys name and/or how to get in touch with him. I'd like to thank him again!