Where can I get them and are they easy to install?

-Tac Latch
http://www.hkparts.net/shop/pc/catalog/detail/219444-2.jpg

robertrtg.com for semi rifle kit.

paddle release, pin, and bushing.

Easy to install?  No.

Where can you get them:

hkparts.net
hkspecialiststore.com
robertrtg.com
gunbroker.com

I'd love to see a write up on how to install the tac-latch II on a PTR GI.

No pictures, but here is the gist of it:

1. Remove mag button retaining pin (if memory serves, knock it out upwards)
2. Remove mag catch, spring, and mag button (cannot do this until #1 is done)
3. Disassemble as if cleaning (remove BCG, buttstock, and lower receiver)
4. Spend the next hour trying to get your fingers to fit in the small space to compress the spring (taken out in #2) and the tac latch, while trying to slide the shaft of the mag catch (also removed during #2) back into the hole.
5. Have a drink and reconsider your approach to #4.
6. Finally, after many failed attempts, succeed at #4. Now slide the new (included in Tac Latch kit) mag release button over the mag catch shaft that is sticking out of the hole for the mag release button.
7. Install a new mag button retaining pin (included in kit, or reuse the old one if you mix them up). Once again, start it from the bottom. Helps if you have a roll pin starter and punches.
8. Be proud of your mad gunsmithing skills, finish the drink you started in #5, and smile.

Total time for someone who masters the fine art of #4 - Under 2 minutes. For the rest of us, about 30 minutes if you include the mandatory cocktail and cigarette breaks.

so, is a PTR-51P gonna need fitting or is it plug/play?

I have two Tac Latches on a HK94 and a V53 and both work great. Easy to install.

Thanks!

I thought some material would have to be ground away for clearance, no? Or maybe?

Ron3

Ralph Smith at RDTS will do a mag release for you. He's in Arizona.
 

I think it is extra weld material around the hole where the latch goes that MIGHT need some trimming down on the clones for the latch to have full range of movement.   It is drop-in on real HK's for sure.

ETA:   Check for this first:

"Tac-Latch's fit all HK's and true HK clones.  All others like PTR91's etc. you are at your own risk due to design changes over the years beyond our control.  For instance PTR91 mag latch shafts are completely round and HK's have a flat.  You can't fit a D shaped hole on a round shaft!!