Experienced long range marksman... I need clarification

[chomomo]

Qualified with loop sling as well.

Semper Fidelis Sir
I recall my USMC training to build a steady platform by attaching a loop sling, keeping my support elbow under the rifle and have my breathing to control elevation after obtaining a natural point of aim,in that the shot gets fired when all the air is released . Yup I fired expert with the M14

I'm kinda thinking the USMC that has taught marksmanship prior to the constitution could learn a few tricks from some expert marksman here on Calgunns . What say you ?

Yes in 94 they still used the loop swing on the A2's, sadly I qualified pizza box in boot camp. But like others have mentioned once you get more range time and live rounds to apply USCM marksmanship fundamentals( not resting the magazine on the floor) you get better. 3rd award expert here.

[russ69]

the point was that it was more than your so called "few hours"

I had more range time at summer camp when I was 12 years old.

[JMP]

It's bad form to rest the gun on a mag for a variety of issues. But, the effect can exist, but not necessarily be dramatic. The magazine attaches to the receiver, which has direct contact to the chamber and barrel, so it is not an optimal support. Ideally, you'd want to support your rifle with the forward part of a free-floating stock or chassis for minimal interference. On my precision guns, they have 4 points of attachment (3 bipod mounting systems and a sling stud). Since these stay sufficiently clear of any key contact point, a different support system is of negligible change.

For an average shooter with a free floating barrel, supporting the rifle with the magazine may result in no apparent change whatsoever.