AR15 trouble stripping first round and mags not dropping free

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I took the trigger guard off even though I could tell it wasn't touching the mag.

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The wear marks are actually on both sides of the front of the mag.

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I took the old one apart....but since its now sorta not a budget build, I ordered an ambi safety, billet mag release, and another trigger guard all in FDE to match the crap I already put on it. When I go to put it back together I'll mic the lowers to see how much smaller the Anderson is.

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So Not sure how this is possible, but it is. So while trying to figure out the best way to remove the roll pin that holds the bolt release in i went ahead and measured the new lower vs the old lower. They were the same, what I did notice though playing with the bolt release without the mag release in when i would push the bolt release the mag (which was tight without the mag release even in the lower) the mag would fall out. The part of the bolt release that rides out into the mag for last round hold open I guess had a bump on the bottom of it which was tilting the mag forward. I put the new bolt release in. Reassembled the lower with the new mag release and ambi safety and the mags drop free now. I was inside so i didnt want to try too much but I chambered a round and it worked as well. It was a cheap PSA lower parts kit that came with the SB tactical pdw brace included. So now I got an extra Spikes Betsy Ross lower to build something else with. Maybe a second 300blk rifle length, will wait and see.