BLUF: i've had mixed success with these (50/50) but it may be because of the other parts i used in the build

i have one in my g48, works great i love it. aftermarket slide, shield mags. shot multiple classes with it, 100% edc confidence. so i thought i'd get a JTT barrel for my frankenstiened g43x...

this 43x is using a factory G43 slide, but the frame is a SCT G43x frame. as many of you know the 43, 43x, and 48 slides and frames are interchangeable, the only difference being the 43 frame is smaller, takes different mags from the 43x & 48x (factory 6rnd and 10rnd respectively)

anyway am using shield mags in the 43x frame with the 43 slide and the OEM barrel. runs flawlessly. i get the Aim JTT 43 barrel and... it doesn't load any rounds with a flat nose. no to HSTs, no to Underwood XDs. loads standard round FMJs though.

i took a look at it next to the OEM barrel, the geometry is a lil bit different right at the bottom of the feed ramp and i guess it's just enough that the flat tip rams into the bottom edge of the feed ramp before the bullet rises up enough to start actually going up the feed ram.

if you look at these pics you can see how the OEM has a sort of curved relief cut at the bottom of the ramp. apparently that's just enough:

https://imgpile.com/p/Ujgstb8

i contacted AIM, they sent me a replacement, it does the same thing. idk what exactly it is. maybe it's the angle the bullests sit at in the shield mags, maybe it's the SCT frame is just slightly different, but i can't get the JTT barrel to run in this configuration. haven't done any further thing, some have suggested taking a dremel to the JTT feed ramp. for now i'm just taking the L and moving on to the next project.