Almost 100% sure that this variability is purely me.

That being said, is there anything I can / should check to if there are any mechanical contributions? Let’s say this was shooting from a rest - what on the mechanical side could lead to wider than expected groups? Inconsistent barrel lock up? Unusual barrel wear? Sights moving between shots? Anything I should check? And how?

The new connector improved the groups but still different and not as tight as with my other 19 and 26’s.

Just to close on this.

Confirmed it's me. I suck. Thanks to 9mm for the refresher. 2021 resolutions - get to the range more frequently - use it or lose it bud. I need to get back into the groove where I'm using the Force more and not thinking as much.

For folks wondering, part of the issue was the characteristics of the different triggers and the tactile feedback when prepping.

On picking them up and shooting groups with them cold...I'm not a Glock Guy...I actually shot a tighter group with G19 #2. It had a longer travel and a rolling letoff.

G19 #1 had a shorter travel, more stacking, and a crisper letoff.

Both were shootable once you got a feel for it's trigger, but switching from one to the other would incline one to slap.

The issue was the fairly common one of investment in the result rather than staying in the process

Interesting.

I was about willing to swear he had some damage to the barrel or some slack and slop in the lockup of the poorer grouping pistol.

BUT - two different trigger pulls definitely can make a difference. I don't own two of any type gun, so I always just attribute any change of group when I switch guns to the fact that I'm now shooting an entirely different brand...

Yea. Honestly, I was thinking it was probably me but looking for mechanical possibility (per earlier post) since I couldn't explain it. And probably didn't want to accept that I suck so much.

What's interesting also is that this affected mostly the 19. The 20, which also has a very different trigger pull, was not affected as dramatically. Not saying I shot well with it (given I still need to relearn trigger control) but not as obviously 'statistically different' as the the 2 19s.

What's also interesting (to me) was that I was comfortable w/ both 19s shooting similar groups awhile back. The difference now is degradation in my trigger control skills and confirmed after the refresher.

I foresee lots of dry fire in my future.

quote:

What's interesting also is that this affected mostly the 19. The 20, which also has a very different trigger pull, was not affected as dramatically.

That's because the stock trigger was sooooo bad that it required additional focus to just get it on paper...at least for me

Replaced the connector so it's the same as the other 19. Along with the quick refresher from 9mm, I think I'm somewhat back on track w/ the 'bad' 19 (again, it was me; connector just highlighted my flaws).

Current group at 15 yards, 1sec cadence. Perhaps similar group but at 15 yards and not 5 yards.

Okay. Passed. 85% in the 10/X ring, 13% in the 9 ring and 2% outside of 9 ring. 150 rounds across 19, 26 and 20. I know I’m not very good. But I'm going to brag that even though I was just shooting at a casual pace, I was clearly the fastest and had by far the tightest group, including the flyers, out of about 30 people. Nobody with RDS; some with lasers (that didn't seem to help much). Next time, may be using RDS at least on the 20 and maybe the 19s. Assuming things are back in stock by then.