[P7M8]

The HK45 mags are staggered. They're the same diameter as the USP45C mags only longer. The fullsize HK45 mags will work in the HK45C as well as the USP45C. The fullsize USP mags CAN NOT be used in the HK45 nor can the HK45 mag be used in a fullsize USP. Mk23 mags and HK45 mags are completely different too.

 

[SidPost]

Thank you! I guess the grip is a little shorter then I imagined. 12/13 round 45ACP magazines seem to be the capacity for a staggered normal length magazine for a full size pistol. From the pictures I have looked at, it was hard for me to tell if the HK45 grip was a little bit shorter then a "standard" full size pistol. That should also make the compact HK45C easier for concealed carry since the grip won't outline as easy.

Thanks again,
Sid

 

[P7M8]

I don't think the grip is actually shorter, just a lot thinner.

 

[SidPost]

Oh ... the rounds aren't truely side-by-side staggered meaning the round above does not touch the round below, only touching the rounds on the opposite side? If that's what their doing, I'm curious how they keep the rounds from binding when you have grit in the magazine without having a really strong magazine spring causing the mags to be a real bear to load.

I wish HK had a good picture of the loaded magazine layout on their website.

Best Regards,
Sid

 

[P7M8]

It's the same as the USP45 compact configuration. I've not heard of any reliability issues with those mags.