Mag not locking if 12+ rounds

[VUL]

I bought an A59XXXX P-07 in August.  I tried recently to load mag with 12+ rounds in it.  Unless I really hit the mag hard (and I mean with some serious force), it will click and then pop back out, or it won't lock at all.  If there are less than 12 rounds or if the slide is back, it is very easy to slide the mag in place. 

This is my first pistol, so I'm curious, does loading a full mag usually require much more force than a non-full mag? 

Any thoughts are appreciated. 

FYI I've put about 300+ rds through the gun.  I keep it very clean and well-oiled.

[donnis]

Loading 16 rds in the mag and pushing it in with the slide forward will take some force to put it in.  Especially if the 17th rd is in the chamber.  I have not had any trouble with putting less than 16 in a mag and inserting it in the gun with the slide forward.  Does it do that with BOTH mags?

[VUL]

It has this problem with both mags.  Again, I really have to slam a full mag to get it to stick. 

Other than this issue, the gun has been great.  I guess I'm trying to gauge how big this issue is. 

[donnis]

If you have 12 or more rds in a 16 rd mag and have trouble locking it in the gun, I would say that is a big enough problem.  I would definitely call CZ about it and talk to them on the phone.  No emails.  I can't imagine why the mag would not want to lock in with only 12 or 13 rds in it.

[armoredman]

Yes, call, sounds like a mag release issue, 1-800-955-4486.

[excheck]

Yes Mr. A.  but he should have problem with the empty mag also. 
Rounds number 12,13,...  are deep inside the magazine and are not touching anything above. 
This is not excuse,  but I never load more than 10 rounds.  I don't need to count,  it is one row in my ammo box and it is IDPA rule and  California law.       

[armoredman]

Not neccesarily, mine will take effort to seat fully loaded with the slide closed, as if doing a tactical reload. I always push mags in hard anyway.
His won't seat at all with that much tension on the rounds pushing up, so I would have it look at.
As for 10 rounds, nah, pass, I like fully loaded mags, and this is AZ, I can do that.  C'mon over across the border, we welcome ALL good gun people, especially Czechs!

[ipijohn]

Never had the problem with my P 07.  I slam the mags in with the palm of my hand no matter how they are loaded, 5 or 10 or 15.  I never load the 16th round, it's too much work and I like to shoot 5 per target so it's multiples of 5 for me.

[czprime]

Never had this problem with mine. Hmmm.   Maybe eating more spinach will help?   Just kidding. DO you experience any major increase in force necesary to push rounds down in the mag as you are loading it past 10 rounds?  I find the force required increases in a nice uniform manner following Hooke's law. Call CZ and see what they say.