I am curious as to how much you each practice with the same ammunition you have in your carry weapon. Do you ONLY practice with carry ammo? Do you ONLY practice with range ammo? Do you mix it up, like 80/20? What works best for you and why?

No set rule for me, but once I've shot enough carry ammo through my gun that I'm confident it's reliable, I hardly use it after that. Maybe once a year or so I'll shoot the ammo I've been carrying and replace it with "fresh" ammo. The rest of my range sessions are with practice ammo, though I usually try to use the same bullet weight as my carry ammo.

I'm with Henry, though I'm less concerned about practice ammo weight.

Each time I go to the range (about twice monthly) I fire the carry magazine from each firearm I shoot. The backup mag then becomes my carry mag. The rest is practice ammo trying to stay with the same weight but don't always make it.

Carry Speer 124 gold dots. Practice with Speer Lawman 124's. Loaded just about the same they say. Shoot my carry mag and load fresh at each range session.

Other than function testing, you don't need to do your practice with the exact load you carry. Just shoot something that approximates it in point of impact, recoil "feel" and other properties. If you reload you can "tailor" your practice ammo even more.

When first purchased I will burn through a lot of SD ammo, between 100-200 rounds. After that every couple of months start with SD rounds in the gun, then switch over to ball for the rest of range trip. Reload carry mag repeat every 3-4 months. I'd say it's more like 90/10 than 80/20 after the initial 100-200 rounds to test it out and make sure I can use my normal stuff (124 HST +P).

I usually shoot bulk (cheap) ammo at my gun club but will on occasion run through a magazine of my carry ammo... the reality is I don't really worry about it. I would think it would depend on your specific carry gun.... from what I've determined over the years two things lead to a failure to fire more often than anything else:
First.... the type of gun.... cheap leads to problems.
Second: training and practice.... more is better.

It is more important that you practice. Using the exact ammo isn't req'd & is expensive. Shoot enough of your carry ammo annually to know what it feels like. Burning off a cou0le mags that you carry annually is a good idea.
This us where reloading come into play too. I can replicate any recoil impulse I want with cheap fmj bullets, any caliber, for 50-75% less than premium carry ammo.

I fire about 200 rounds of my carry ammo to check for function and accuracy. I generally don't shoot my carry load unless the ammo has gotten wet, or there is some other reason to needto reload the magazines. I haven't fired any of the ammo that's in my HD magazines in about five years. Those mags sit in a battle belt in my bedroom closet, so there is no reason to rotate unless something happens. I genarally train with whatever weight I'm carrying, although at self defence distances POA/POI doesn't change much no matter what I shoot.

I only shoot carry ammo.
Except for when I'm shooting Cowboy. Then I shoot canned Bunny Farts.

I shoot practice ammo. But, our duty round is 147 grain, and a lot of the 147 practice ammo recoils similarly. Every six months, I shoot up my carry ammo and replace it with fresh.

We carried the WW 147 Ranger T or SXT. Winchester had a fmj load that was identical in its ballistics the same. The NJ AG demanded that.

Other than the time I got 500rds of Speer GD LE turn in ammo for a very good price, after verifying carry ammo function, I just shoot range ammo.

If hand loading, I do 124g at about 100fps shy of the full power 124g carry loads.

After function testing the carry ammo, (Federal HST) I’ll use Federal 124 AE FMJ for shootin. It approximates the standard pressure HST pretty closely, as does Speer Lawman. Blazer Brass 124 seems to be a little lighter, but that’s still ok to me.

I shoot mostly practice ammo at the range with my semi-autos. I'll shoot a mag of defense ammo once a month or so. The only revolvers I shoot regularly nowadays are J frames which I do carry quite often. With those, I'll shoot my carry ammo most of the time since I'm not shooting them for extended periods, just enough to keep in practice at 7 yards or so.

Our department would qualify 4x each year. Two of the quals were done with carry ammo, this way we rotated the stuff every 6 months or so.

I now shoot my carry ammo during my retired officer LEOSA shoot each year.

I do run a box or two of carry ammo through each new gun, used to run more through them when my ammo was free - but nowadays...

I practice with FMJ 98% of the time.

Once per year at our summer qualification, we shoot our duty ammo and replace it with fresh, and every couple years I'll shoot the defensive ammo in my personal handguns and replace it with fresh.

Other than that rotation, the only other time I normally shoot defensive ammo is when I get a new handgun, at which time I'll run 100-200 rounds of defensive ammo through it to ensure reliability.

I've also been to a couple firearms classes that specifically used duty ammo at times, such as when shooting through intermediate barriers (cars/glass/wood/etc.) and examining the results, or when practicing night firing.

Since I don't bleed cash, I practice with FMJ reloads and only shoot an occasional magazine of my carry ammo to help with the rotation.