What is the secret to getting the mag base off? The mags are G19 15 rounders. Thanks

Use a fine flat tip screwdriver. Insert in a angle towards the front strap of the magazine. Get the tip past the insert and then use the screwdriver as a lever and pry forward.

The "offical" way:

1)  Depress the button in the center of the floorplate with something that won't scratch it up.

2)  While keeping the button depressed, push one corner of the back side of the floorplate against a hard surface.  Given the right angle and enough force, this will pop the floorplate loose.  It can then be slid off.

It also helps to sqeeze the bottom of the mag body once you depress the interior floor plate.  It actually allows the base plate to clear the detents MUCH more easily.

Ok, I got the spring changed, but the damn thing still won't feed hollow points. WTF!!

Do you have some different mags to test with. Maybe it's the ammo.

I've been using Gold Dot for about 2 years, it has always fed fine until about a month ago when I discovered the last round wouldn't feed. This was with the factory 10 rounders. The 10 rounders always fed every round until now which is why I decieded to use them instead of my 15 rounders, i'm pretty sure its a worn spring issue with them.  

I figured i'd try to get my 15 rounders going, but no luck. They will feed FMJ just not the JHP.

OK that's a slightly different story.

I have replaced all my factory glock high cap tubes with scherer tubes. The reason I did this is I shoot IPSc and the scherer tubes drop free, where the NFML tubes I have do not.

Glock mag tuning

One big issue was the followers. The followers need to make it to the top of the feed lips. In fact I found that it works best if they make it past the feed lips a little. To do this I used a dremel and removed some material from the followers (sides and rear) until the followers made it to the top. As a alternitive you may try a different follower.

To test it I load one round in the mag and put it in slide lock. then I drop the slide and if it chamber the round, it is good.

I may use a dremel and take little off the follower, that seems like it would solve my problem. The last round just doesn't make it up high enough and the JHP's just jam on the feed ramp.  And with the follower coming up a little higher, it seems like it would help out.

I did try the follower from the 10 rounder in the 15 round mag, because it seemed like it would tilt the round up more than the one on the 15 rounder, but it also jammed on the last round so it didn't matter anyway.