What's new
HK Proshop : For the Heckler and Koch Enthusiast

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

HK433 discussion/info/resources

Barn Owl Lover

Well-known member
Feedback: 0 / 0 / 0
Joined
Mar 4, 2021
Posts
527
HK433 and 437 will be available from 2022 (armed forces and LE, and no firm date given as of yet)

HK-02_HK433_IMG_E0391-e1639065785226.jpgHK-03_437-im-Schuss_IMG_0439-e1639065711812.jpgHK-00_IMG_0474-rotated-e1639065805137.jpg
 

Barn Owl Lover

Well-known member
Feedback: 0 / 0 / 0
Joined
Mar 4, 2021
Posts
527
Tech question, though I doubt there's currently a conclusive answer (ie, too little info out there). How is the barrel in the 433 mounted in the receiver? In this set of patent images (gen 3/4 rifle, though I doubt this has changed much), it does show some of how the barrel is fitted into the receiver, and one of the illustrations shows what appears to be a G36-type barrel nut:


I know that it's not like the SCAR or Bren 2 where the barrel and trunnion are integrated and bolted into the upper. And we have to remember that the G36-based XM8 had quick change barrels as a design feature (though it required a special barrel nut wrench and the rifle possibly having to be mounted in a vice for it to work). And I did see a World of Guns video on YouTube where a G36 was dis-and reassembled. On the G36, it seems that you loosen the barrel nut and the barrel slides out and interfaces with the trunnion with 6 radial lugs that interface with the trunnion and the barrel nut.

As as can be told as of now, does the 433 use a version of this system, or something else? HK did credit Sig Sauer as far as something related to the barrel in the patent documentation. But it seems that the 433 and the MCX use a different barrel change procedure. And those two lugs on the underside of where the trunnion is set looks like attachment points for the block that locates the handguard lock and where the front of the lower locks onto the upper.
 

Barn Owl Lover

Well-known member
Feedback: 0 / 0 / 0
Joined
Mar 4, 2021
Posts
527
Latest 433 pic I found, though not "new" new given it was taken a few months ago by Concamo:

concamo.camouflage_271130276_458999552555009_1405584888098408459_n.jpg
 

Barn Owl Lover

Well-known member
Feedback: 0 / 0 / 0
Joined
Mar 4, 2021
Posts
527
I also wrote to JPW_Fides today, and he did recently see a HK231, but HK didn't want him to take photos of it yet. So, it too, exists.

I also translated the PDF that I posted, and it seems that HK are fans of the 7.62x39mm (though they never mass produced a rifle in that caliber before, though they tried with the HK32 in the '60s).
 

Barn Owl Lover

Well-known member
Feedback: 0 / 0 / 0
Joined
Mar 4, 2021
Posts
527
Anyone think that the HK231 will use a bolt similar in concept to the MG5 bolt and the bolt for the CZ Bren 2 PPS with interrupted lugs (a large front set and a smaller rear set)? HK in their MG5/MG121 patents say that such a system allows for a more repeatable and more secure lock up, while also making the weapons equipped with them "more soft-shooting". I wonder how such a system achieves the latter characteristic.
 

Barn Owl Lover

Well-known member
Feedback: 0 / 0 / 0
Joined
Mar 4, 2021
Posts
527
437 from Concamo:

274525144_361595102636381_2370295546354642444_n.jpg

I'm also hoping for some 231 and 132 news at EnforceTac, though I doubt it for sure for the 231. The 433 and maybe 437 should be there, though.
 

Barn Owl Lover

Well-known member
Feedback: 0 / 0 / 0
Joined
Mar 4, 2021
Posts
527
New video from HK's Grey Room in Georgia of the 433. Includes a detail examination and a mostly complete field strip. Also basically the most up to date variant of the carbine version:

 
Top