HK P30 / SFP9 / VP9 +2 Magazine extension

cults3d

This is perfectly functional +2 magazine extension for 15rd HK P30, SFP9 and VP9 magazines. It's rather tough and avoids some mistakes I've seen other designs make, making possibly the best 3d printable design out there. It uses factory spring and follower, maintains slide lock back feature and fully loaded can be easily inserted on closed slide (there is literally 1mm wiggle room to get both of those features to work). Properly printed from the only improved PLA i have access to at reasonable price (Fiberlogy's Impact PLA) they easily survive drops on concrete from height of 2 meters. The latest version took me about half an hour of medium strength throws on concrete ground to break. Not drops, throws. Kinda surprised me to be honest. Just keep in mind it's a 3d print. Variety of factors influence strength of a print, the design itself is only one of them. Your prints might be stronger or weaker, so i highly recommend doing some tests yourself to learn how much you can expect from them. Material: As i already mentioned, during my testing i got the best results using Fiberlogy's Impact PLA. Various types of PLA+ should also work well. PLA is too brittle and easy to crack, but generally doesn't break catastrophically. This is what i recommend it you don't want to use one of the improved PLAs. You will get a functional print that will survive some very mild abuse. PLA parts might need frequent replacing tho. I don't recommend PETG at all. Depending on manufacturer it can give results similar to PLA or literally shatter on impact. In fact this was the fate of the blue one from the pictures. It looks nice in the pictures tho, so it's there. What you will need? M3 threaded insert (one that is around 5mm long, there is a variety of different designs out there), one M3x12 countersunk head screw and something hot to put the insert in (you can also use a long M3 screw to hold the insert and heat it up with lighter). Closest imperial equivalents might work, but i don't have easy access to those. Feel free to test for yourself. Assembly: Threaded insert goes into locking plate from the top (4mm round hole). Replace the factory locking plate with the new one and compress the spring until it's flush with the magazine body and hold it there. Slide the main body onto the magazine body. Insert the bottom plate in it's place. The screw goes from the bottom (the hole is a bit undersized, so that screw cuts it's own thread in the plastic) into the threaded insert and locks everything together. Magazine spring should provide enough pressure for the whole process to be nice and easy. If not, print some rounds or use snap caps to load the mag and increase the pressure. I also added an M3 hex nut version of locking plate. It might need a bit of glue to keep things together for assembly. I didn't drop test it, so i would still recommend the threaded insert version, but if you want to use hex nut, you have the option. Weak spots: This is a pretty tough design. But if you do manage to push it to breaking point, it will break primarily along any print imperfections. If your print came out well, there will be two primary points of failure. Both main body and locking plate may brake along layer lines about 6-7 mm from their respective fronts. It takes a good effort to get there, but keep that in mind, Broken locking plate might make it difficult to disassemble the whole thing. I generally mange to always do it, but in an unlikely scenario you won't: remember it's just PLA, put in in the oven set to 60-70 degrees Celcius for a few minutes and it will become soft and easy to remove.