Nice set of rifles brother. Bottom one looks like it has the BCM grip on the front. I have them on all my rifle except my RRA. I spin it 180 and it makes a hook for my hand to pull back on.
Thunder ranch is a well know firearm training school : https://www.thunderranchinc.com/ . Clint Smith : https://www.thunderranchinc.com/about-clint-smith/
Welcome from Indiana, Northwest corner. What part of the are you ? Even Rock River poly mags recommend a little filing to work better for release. Try that. I have the Standard Operator.
I shoot pistols with both hands both eyes open.. Rifles left hand. Tried right handed for just in case. Prefer left hand. Impact guns has left hand rifles section also.