Shot my Glock 20 today and used a couple of new mags I bought.  At first I could only get 10 rds in each, then 11 in each, then just 11 in one mag and 12 in the other.  Didn't bring my mag loading tool.

Any tips to being able to load all 15 rds without the tool? Will the springs eventually break in so I can load all 15 rds without busting my thumb?

All I can say is...

take it like a man.

Or load em all the way up and let them sit for a few weeks / months / years.

They always seem like that

Use the loader supplied and leave them fully loaded for a couple of weeks. That should help. They will get easer over time.  

How long can you leave a glock mag fully loaded with out hurting the springs?

Quoted: How long can you leave a glock mag fully loaded with out hurting the springs?

Same as any mag.  Forever.  

Quoted: Shot my Glock 20 today and used a couple of new mags I bought.  At first I could only get 10 rds in each, then 11 in each, then just 11 in one mag and 12 in the other.  Didn't bring my mag loading tool. Any tips to being able to load all 15 rds without the tool? Will the springs eventually break in so I can load all 15 rds without busting my thumb?

I never have trouble.  Time for you to man up.  

Quoted: Quoted: Shot my Glock 20 today and used a couple of new mags I bought.  At first I could only get 10 rds in each, then 11 in each, then just 11 in one mag and 12 in the other.  Didn't bring my mag loading tool. Any tips to being able to load all 15 rds without the tool? Will the springs eventually break in so I can load all 15 rds without busting my thumb? I never have trouble.  Time for you to man up.

yup

Honestly, guys...  I can sympathize with this guy.  I dunno what the hell Glock is doing with their followers lately.

I have ten new hicaps for my 23 that I bought when the ban lifted. The last round was semi-stiff to load in all of them at first.  Still is, and nothing that I tend to worry about. It's the last round after all. But I can do it readily by hand, no loader tool, and there is about two-three millimeters space that you can still depress the top round. Makes it real easy to seat the mag under a closed slide.

However.  I just bought five more last week, and every single one of them is an absolute bitch to load. Even with the tool, i'm having to push down on the 13th round awful damned hard, and it's 'snapping' into place under the feedlips with an audible sound. At this point, there is no slop space left (you cannot compres the rounds down at all) and you have to practically pound the mag in to get it to seat under a closed slide.

This is not, in my opinion, right. No other pistol mags I have behave this way.

Get an HKS magazine loader. It's a hell of a lot faster and easier to use than the one that came with the gun. SG has 'em.