trigger pull difference between dry and live fire - question

Dry firing my Les Baer .45 is incredibly smooth for me, both when I just reset the hammer and also when I cycle the disconnector.   The pull feels much harder when I am live firing and today I actually loaded a round, removed the magazine and confirmed the trigger bow was not rubbing on the magazine. That shot was also hard pull.  I don't know how to measure trigger pull safely with a live round.

What should I check to rule out all possible technical issues?

Make a dummy round???

Interesting idea, fire a known live round and then trigger pull on a known dummy round to confirm whether the stiffness is in my head or in the gun.

See my comment in the Fundamentals section.
CR

CR10X wrote:See my comment in the Fundamentals section.
CR

Under what thread, could you paste a link to it?
- Dave

This one Dave,  https://www.bullseyeforum.net/t8868-trigger-and-grip-not-playing-nice-together

A couple of issues come to mind. Removing the magazine with a loaded round eliminates any magazine created problem and the possibility that if you do have a stop screw the magazine is altering the location of the Mag Catch since the stop screw uses it too.
 What it don't change is the way the slide closes, the slower closing speed could be changing the way the trigger is set up as compared to dry fire. Might want to close the gun with a loaded magazine then carefully lowering the hammer followed by resetting it or use a dummy round.
 Another can be the grip safety, shooting the gun knowing it has a loaded round in the chamber your grip could be a little tighter or not exactly the same as with an empty chamber. Because the grip safety uses same spring as the sear and disconnector the changing pressure can effect trigger pull. When I set up the grip safety spring I alter the curve so that the leaf for the safety touches the frame when the main spring housing is put in so that any safety pressure on the leaf flexes it only the amount beyond the point of the location it contacts the frame and not effect the sear and disconnector leafs.
 Another thing to look at is your grip itself, the trigger finger gets harder to move as grip pressure increases.

An update.   

Cecil suggested looking at the grip safety and seeing if it was rubbing on the trigger track.   Since this is a long trigger I installed, it was.   I slightly relieved both and did a safety function test which it passed.

While I had the trigger out (STI glass filled), I noticed some areas it was hitting the frame at the end of travel so I dealt with that too.

When I reassembled it I added a felt cabinet door bumper to the grip safety (another Cecil suggestion) to make sure it was closing all the way with my grip (and my ergo grips).

I also received a suggestion from Jon to check there was no difference in the frame/slide alignment between dry fire and live fire.  I built some dummy rounds to safely do tests at home, and there was not an alignment issue.

Froneck (sorry, I have not learned your first name yet), my slide closes faster at the range (closing on first round with slide stop) than when I move slide to half-way before releasing during dry fire.  I did not bend the safety leaf, I may do that in a future detail clean.

When reassembled and lubed, I could not tell a difference between the empty and magazine-fed dummy round comparison.   Next time at the range will confirm how much of it was me.

Froneck, I made from Fr On Eck as pronounced stated as one work and is Polish for Frank. I have no idea how it's spelled in the Polish language.
 My gun has a similar problem, trigger gets harder and harder to pull as the match continues depending on how many 10's and X's I have. My .22 has the same problem. at one match I shot 9 X's slow fire the trigger got so hard to pull I shot a 6 and wound up with a 96-9X! Dam cheap Hammerli 208, just can't get good guns anymore!