It's very fussy, as in :
If I open up the lips a tad too much, if I slam the mag in hard (which may happen on the field), I get rounds ejecting from lips.
Also when opened up too much, last rounds are already pointing up, and bolt can pass over sometimes without catching round.
If I close them up a bit too tight, they will hit the feedramp and feed.
I can now get them to all feed, and smooth to some extent too, but after measuring concentricity before and after feeding, hitting that ramp has a negative impact on runout.
My reload process is really meticulous and focused around 0 thou runout ammo, which I have succeeded, I feel like I am scrapping my efforts by having ammo come back out with runout after feeding.
And, the margin between too open and too close is very tight, less than 10 thou, go 5 thou one way it behaves a way, go 5 thou the other way it behaves another way.
If I should drop mags or handle them rough, I may be in for surprises on the field.
I personally got no beef with ultimatum or their product,
It's my fault for diving in too quick, and thinking I was purchasing a drop in action, when in reality I purchased a gunsmith required action, when in combination with my caliber, mags and chassis at least.