I recently got a Lee Pro 1000 press for my .45acp rounds.  It took a little time to get it set up, but now it runs great.  The only problem I seem to be having is that sometimes I'm getting primers that are not fully seated.  When I run them through my 1911's, the firing pin hits the primers, leaves a little dimple in them...but it doesn't set the round off.  I usually get 4-5 out of 100 round that do that.  If I run the same rounds through the gun a second time, they fire off just fine.

After looking at some of the rounds I've loaded up, I can tell that there are a few that are just slightly high, and not fully seated.

Has anyone else had this problem with their Lee Pro 1000? Is there any way to adjust how far it seats the primers? Or am I just not pushing down hard enough on the lever to fully seat the primers?

Thanks!

Most likely it is operator error. I had a Dillon 550B and I would have the same issue once in a while. After every 50 rounds, I would make sure the primer tray(or what ever feeds the primer in the loader is called) was brushed clear of debris. When depriming, sometimes dirt falls out onto this tray and it feels like you properly seated the primer.
Hope this helps.

Probably so.  The Pro 1000 just doesn't seem to have very good primer seating feedback through the handle the way a single stage press does.  For some reason I find myself having to be extra careful to give the primer a bit more force at the end of the downstroke than what feels right for whatever reason.

Although it is also possible that you are using primers with harder cups that your gun really likes.  A brand change could help if nothing else works.

Firing when struck a second time leads me to beleive it's a primer issue.

I've alwys found a good indicator of my pro1K seating primers to be that little lurch at the top of the stroke.

I never had the problem with I was making my loads with my single stage press.......I just started having these issues when I started loading rounds with the Lee Pro 1000.  I'm using CCI primers....never had a problem with them in the past.

ive seen an old and abused pro1000 not fully seat the primer due to the actual base of the loader being worn out where the pin sets against while pressing the primer into the case. this is extreme though. that loader was beat up/misused pretty badly.
I dont thinkthis is your case though.
you may want to ck and see if the primer rod the seats the primer isnt upside down?
imo...cci primers are they way to go when using the lee1000
correct shell holder?

You might just be short stroking when priming, after using the Pro1000, you'll get a feel for everything. I check all the ammo I reload the way Dryflash mentioned, helps weed out the occasional mis seated primer.

I actually squeeze the arm and the back pillar with my thumb and index finger to ensure i have put a stron engough force on the primer without actually ripping it off the bench. Works well for me, no issues since i started doing it. The action of squeezing is a pretty naturalone almost like using the hand prime and very controllable/repeatable.

could be 2 things. your press is not mounted firm enough. you are not pushing the handle far enough. the pro 1k primes on the upstroke. I can feel the primers seating. never had problem with my pro1k in 45