ok. finally got to the range to test. took my g19, and my sig p227. yes, i do intend to carry that too.

 

 so on the g19. 5 mags. 1st mag, ran factory glock 10 round mag. 6th round stovepiped. cleared, next round didn't stovepipe, but failed to eject. next round stovepiped . ok. that mag ain't gonna run this stuff. the rest were magpul 10 round mags. flawless. she didn't skip a beat.

 i think i'm gonna order some magblocks for my normal capacity g19 mags, go to my friends house and block a couple to 10, and see how blocked mags function.

moved on to the p227. 4 mags through that without missing a beat. factory sig mags. there's not really much to say about this one. 'cept that i can't find a machined slide for it, lol.

 

 something that had been mentioned to me.....fort scott munitions "tumble on impact" ammo. anyone tried that yet?

It’s always extremely prudent to test your carry ammo in your weapon. 
 

Last weekend, I brought my carry G19 and my G43 to the range. 
 

In addition to a lot or range ammo, I shot 50 rounds of Federal HST through the G19, and as expected, it fed flawlessly, as it always has. Total confidence in that combo. 

The G43 was another story. The hollow point cavity of the HST hung up on the front of the G43 mag and produced a failure similar to the OP’s issue with Critical Defense. 
I had to shave a little plastic from the front of the G43 mag to get it to feed the HST reliably. Once I did this, I had no more issue. 
Still going to run a few boxes of HST through it, before I call that gun/ammo combo good to go. 

8 hours ago, Displaced Texan said:

It’s always extremely prudent to test your carry ammo in your weapon. 
 

Last weekend, I brought my carry G19 and my G43 to the range. 
 

In addition to a lot or range ammo, I shot 50 rounds of Federal HST through the G19, and as expected, it fed flawlessly, as it always has. Total confidence in that combo. 

The G43 was another story. The hollow point cavity of the HST hung up on the front of the G43 mag and produced a failure similar to the OP’s issue with Critical Defense. 
I had to shave a little plastic from the front of the G43 mag to get it to feed the HST reliably. Once I did this, I had no more issue. 
Still going to run a few boxes of HST through it, before I call that gun/ammo combo good to go. 

yea. i'll be running more through. i kept it short on the 9mm because they didn't have any in stock for me to replace what i was shooting.

 

 i'd asked about the fort scott stuff because they had a gel block with a normal round, ft scott, and critical defense. the cd left a surprisingly small wound channel compared to the ft scott.  they did tell me though that the ft scott could over-penetrate.

I use the ft scott in my 1911 9mm. Could not get the critical defense to feed at all...