Great video and I
really do like the graphics. Way more modern and stylish while getting the point across better.
SR25s and ArmaLite AR10s have used a longer mag catch shaft as best as I can recall dating back 20 years now. I know at least that the ArmaLite Inc. ones are longer.
Have you tried a Norgon ambition catch for AR10?
NORGON AMBI-CATCH
I was thinking exactly what you were before you said it. The ambi latch you got appears to have been de-burred in a tumbler.
I personally de-edge, blend, and polish my extension feed ramps to match the receiver feed ramps, and also take some edges off on the extractor clock location barrel extension teeth leading edges that are hard to get to.
That helps alleviate the vampire necks on my brass caused by the ejector forcing the spent case violently against the extension teeth.
Funny thing about my .260 Rem GAP build on DPMS receivers/BCG is that it feeds regular Berger VLDs like it was meant to, even though everyone told me it wouldn't back when I was looking for good bullets for shooting distance.
Everyone else I know has had problems with meplats slamming into the breech of the barrel.