Interesting Bartman! Keep it up and thanks for posting results.
Seems you are finding they behave differently operated fast and hard in some cases,and with a full magazine?
I haven't run an actual test like Bartman has, but IME cycling troubles have happened more with a full magazine. I learned early in my reloading experience to run the first reloads in any new batch through the rifle as a test to make sure they cycle and chamber, etc. no matter how many times I have proven that recipe.
A friend of mine who was on the Marine shooting team told me that he loaded his 1911 one short of a full magazine because it cycled better that way from the first shot. I do the same: three rounds in a four round capacity magazine when hunting, etc. When the magazine is full that first round is stacked hard and is harder to get out and feed smoothly.
Oops: this posted before I was done so am editing to finish it.
