A little bit of “Zen” with battle rifles?
Not quite sure what you mean by "Zen", but there are things that will increase your harmony....
One of them is not just knowing, but understanding what you are using, and why it is made the way it is, and does what it does.
With milsurp rifles (all classes, actually) I find shooting things is more enjoyable than shooting paper targets. What I mean is, if you want to shoot teeny groups, there's guns for that. And while some battle rifles might do it, they were never made to do that, and its foolish to expect that.
For me, something like an offhand shot busting a water filled 2L pop bottle at 150 yds (with an SVT 40) was more rewarding than any paper group off the bench.
Sights and triggers range from pretty good to horrid and crude and part of the fun is the challenge of being able to use them as well as one can.
Remember that they are made for young(er) men to use, and for unexperienced men to be easily trained to use to a military acceptable level.
Shoot paper groups enough to be sure th bullets will hit close to point of aim, not several feet away, but don't try to make an MOA shooter out of them. IF you find one that is, ENJOY it.
Shooting plastic bottles or cans or other things that react, but allow relatively easy range clean up afterwards is great fun, for me, and friends. Balloons are really fun, tethered on a few feet of string, they bob and weave and aren't always as easy to hit is one might think.
I take the broad view, "battle rifles" to me are any and all the military pattern rifles that are not "assault rifles" (and here, I am using the actual, proper definition, NOT the current political one) , and while most people think in terms of the HK/FAL/M1A etc., I include all the "battle rifles" of their day, which includes the bolt actions, single shots and even muzzle loaders of the era.
I guess my point here is to enjoy the history, the shooting, and not to expect anything they aren't and were never made to be.
It can be a form of meditation, if you approach it from the right state of mind.
Just don't ask me to get into a full lotus position,
couldn't do that 50 years ago, no way its happening now,