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HK 33k locking pieces

5407 Views 13 Replies 8 Participants Last post by  bauerdb
Can someone knowledgable on the subject of 33k locking pieces please list all the locking pieces for the 33k (1/7 twist barrel, factory German guns) and list the applications for them (type of ammo, etc...). I cannot find any info anywhere.please only post if knowledgable on this subject. Thanks guys :)
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Yeah doesnt really list the 33k (different barrel length than 33).
The only experience I have is my own. 15 wouldn't run, 7 runs perfectly. I believe most 33's came with #8 LP's and there's only what, an inch barrel length difference? I'm thinking an 8 would work fine too.
Are you running a clone or 93 cut down to 33k specs?
IGF clone, malay barrel cut down. The entire bolt group is HK factory.

Side note, the only reason I bring up the #15 is because someone I trusted knew what they were talking about recommended it. Someone smarter corrected the mistake when I had problems.
The two original 33k kits i picked uo came with a 15 and a 3. I am really looking for more info & history about the different 33k lp's. What ammo designed for, i know the latest ones come standard with a 3 lp. Maybe G3Kurz can answer. Thanks for trying to help though. I appreciate it. :) I am currently running a 3 lp im my sear host 33k (hk93 convrrted with a original 33k kit, 1/7 barrel).
Standard HK GmbH factory-produced HK33K's were shipped with # 3 locking pieces (58 degree, ID# 203384). This same piece is used with the HK53 with 1/7" twist and M855 ammo (or the # 15 piece with M193 ammo).

Generally speaking as the barrel length DEcreases the angles of the locking piece INcrease.
G3 = 45 degree, G3K = 50 degree
HK33 = 55 degree, HK33K = 58 degree, HK53 = 65-70 degree
G41 = 43 degree, G41K = 45 degree
The MP5/HK94 family is the notable exception - they are all over the scale for various reasons (desired rate of fire and/or stock and suppressor use on the K, barrel porting and suppressor in the SD, calibers in 10mm and .40 S&W, etc.). The subguns tend to be somewhat less sensitive to locking piece variances.

I most conventional small arms want the chamber to remain closed/seated until the projectile and high pressure gases leave the muzzle. It is the angles on the locking piece that greatly determine "unlocking" time or more accurately for the unlocked HK-style roller-"delayed" bolt system "opening delay". This determines proper and reliable function and rate of fire to some degree.

Of course all this varies based on the ammo type used and other factors (suppressed, box versus belt fed, special coatings, condition of the gun, etc.). At one time there were over 80 different angle locking pieces for the G3 family alone based on the variances in ammo around the globe.

That should help.

I will ask Straightgrain to post the "Appendix B" locking piece list here which provides a more detailed list than that posted here in this thread.

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Yeah doesnt really list the 33k (different barrel length than 33).
Yeah, I'll read more and post less...
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Awesome last Post Sir, very much appreciated! Blast from the Past for sure!
Is the locking surface on this #3 ok? I’d imagine pitting here is not the best for functionality.


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Is the locking surface on this #3 ok? I’d imagine pitting here is not the best for functionality.

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If the gap is in spec don't worry about it. Just check it every 1k rds or so.
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