New style barrel extension in HK416A5 and MR223A3

HK416A5 (and MR223A3) does have numerous changes and upgrades over older variants. Some are easily noticeable, some require closer inspection and some are well hidden. One of this well hidden differences is design of how barrel extension interfaces with upper receiver and how it is positioned.
In my opinion new method whit cut out in barrel extension and wedge on upper receiver is much better idea that classic barrel extension pin in AR15. New design is simpler, stronger, more fool proof and provide better positioning in barrel in relation to upper receiver.

Cutting HK MR223/MR556 barrel - good, bad or ugly?

There were several discussion on cutting and re-profiling 16.5" heavy match barrel that HK installs in MR223 and MR556 series rifles. Profile is rather mater of personal choice and taste, but cutting down generates some controversy. HK claims that when they cold hammer forge their barrels, they make them in way that barrel bore has a swage (constricts) toward muzzle. Barrel is manufactured for it's final length, so cutting it down remove this narrower portion and affects barrel performance. I decided to find out how it turns out in real world.

Glock 17 Gen2 ends its career in style

My friend had and Glock 17. It was Gen2 (CNM series), that he bought used some10+ years ago. It was not used a lot by security company that owned it, they mostly carry, rarely shoot (even for training). But my friend, he shot it a lot. And he shot it good (he is one of best IPSC and IDPA shooters in country). He even cleaned it... once a year or so. (Pictures inside!)

HK P30/P30L short travel LEM (CDA) trigger V4.1 aka V4 CH

For last month or so I'm testing reduced travel LEM (called CDA in Europe, for Combat Defense Action) trigger, that I call V4.1 (internal HK designation V4 CH). What this trigger group does is reducing pre-travel  on P30 LEM trigger by roughly 1/3, from 15mm (0.590")  to 10mm (0.393") measured in middle of trigger height. After initial pre-travel there is 1.5mm (0.059") of sear engagement travel (think of it as second stage in 2-stage trigger) and 1mm (0.039") of over-travel. Sear travel and over-travel are same for all variants (V4.1 does not change that) except for V6, that is "real" DAO trigger. Reset is same as standard LEM trigger at 7.5mm (0.295"). 5mm (0.196") of reduction may not sound a lot, but in real life it make big difference. It no longer feels like eternity to take up LEM trigger, so there is less tendency for trigger jerking during fast shooting. Overall feel is very good.

For those wondering how to get this trigger, nice guys from HK sent me conversion chart for every P30/P30L trigger variant and give green light to share it.

How to mod H&S Speedsec 5CW HK USP speed holster to work with HK P30, P30L, HK45 and HK45c

When I got my first P30, I hand on hand my first IPSC speed holster for HK USP: Hoppner and Schumann Speedsec 5CW. I modified it to work with P30 using Dremel tool with cylinder shaped milling bit and hand file. 5CW is made from polymer so use low speed and work slowly to not overdo. Modified holster still accepts HK USP, but also works with USP Compact, P2000, P2000SK, P30, P30L, HK45, HK45C and even HK P7.

AR15 muzzle device on HK MR223

From time to time I get asked about how to mount AR15 muzzle device (1/2"x28tpi thread) on HK MR223 rifle (M15x1 thread).

Basically there are 3 solutions that do not include messing with barrel on HK MR223:

1. Get muzzle device with M15x1 thread straight from manufacturer.
2. Re-thread muzzle device from 1/2x28tpi to M15x1
3. Make screw on adapter that is female M15x1 thread and male 1/2x28tpi thread.

I tried all 3 solutions, so decided to share from what I learn.

List of triggers that work with HK416, MR556A1 or MR223

This question comes back every so often. I decided to try collecting list of trigger groups that work with HK firing pin safety, so can be used either in lower other than HK or dropped into HK lower. Looks like most M16/M4 select fire triggers work with it, so list is of semi-auto triggers. Please take in mind that HK firing pin safety takes some hammer energy to disengage. Using very light trigger setup with light hammer springs can lead to light primer strikers on some brands of ammo (surplus, Russian, etc.):

ALG Defense ACT
Armalite National Match 2-stage
ATC AR-Gold Trigger (needs fitting for MR223 due to rear receiver pin location)
CMMG Gen2 2-stage
Franklin Armory Binary Firing System III (BFS III)
JP Competition Trigger
JP EZ Trigger
Geisselle HK MR556
KAC 2-stage
RRA National Match 2-stage (CAUTION: Only new version with rounded hammer is compatible)
TAC-CON 3MR 
Timney AR-15 Skeletonized
UHL Trigger (German made)
Wilson Combat TTU-3G and TTU-M2

I will try to update this list when new info will come in. Please give confirmed info on other triggers, I will update list.

WARNING: Some triggers will not work properly with HK safety from 2-stage "European" trigger (one that allows to be put on safe with hammer down). Old style HK safety or aftermarket safety may be necessary.

Remarks:

Geisselle SSF - standard model reported not to work reliably with HK416, special model required.

Last update 27th of Dec 2017 (BSF III added)

Video installation instruction for LEM conversion on HK pistols.

HKPro forums member Carrera prepared great and detailed video instruction of how to install LEM conversion kit for HK45C pistol. Because trigger systems in HK pistols are similar this instruction can also apply to HK USP, USP Compact and HK45. Also it will help with P2000/P30 series conversions, however different parts kit is required. Parts look same, but hammer pin has different diameter on P-series.

Carrera also prepared detailed written instruction in pdf file, that can be found on  HKPro under this link

Next video after opening post