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Discussion Starter #1
Picked up a used but nice MKE trigger pack. Made an observation and decided to do some searching of the forums for an answer to my question. Didn't come across one so here goes.

The remnants of the auto sear in the pack rub against the neutered hammer and cause it to drag. The hammer feels sluggish and I don't like it. Is there any inherent problems with removing the vestigial part and replacing with a semi type bushing?
I can't think of any but thought I'd ask the hive before going to the hassle of pulling it apart.

TIA.
 

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Looks like the hive has hibernated, so I’ll take a crack at it. I’ve been tinkering with a MKE pack off & on for a number of months now. First, like I’ve done in another post, I salute their ingenuity at cutting overhead costs by figuring out how to adapt the FA configuration for semi with some simple machine work. But it’s caused a few pains for tweaking. The friction sear rubbing the hammer you are talking about is one of those leftovers from the FA configuration, and yeah, it’s a nuisance, but the sear spring won’t have a perch to get tension from otherwise. Yeah, I saw that early on, poked around on it and the friction pressure isn’t that horrible, though I did two things to alleviate the interference — micro-polished the hammer in the area where it contacts that sear, and sorta re-tensioned or re-spring the sear spring a bit to where it doesn’t have near as much force as it did. And that did a part at tuning things in the direction I was wanting to go. When I get ahold of a trigger assembly, I study closely what rubs on what, what the parts do, how they interact along the range of their movement and all. I’ve been going slow, changing things a bit at a time, measuring the results, going out and shooting it and so forth.



Measured this parallel and in line with the barrel, like you’re supposed to.

Interesting thing is I had been getting a consistent 5lbs 22 ounces in the past, but this was taken after putting in an HK German hammer spring, which is a little longer than the MKE. Trigger feels rather “crisper” than before too. With the original MKE hammer, sear & trigger it was always real draggy & crunchy, but all that MKE stuff has been changed out, the replacement parts hand fitted & polished - now it’s just a bit draggy but with a cleaner break, especially after the new spring.





4lbs, 10.8 ounces. This measurement was taken in the way I hold & pull the trigger while doing a rapid fire — I slide the hand down the grip at more of an angle and pull the trigger more on the end and not in the middle like normal. Was typically getting 4lbs and 12-15 ounces before using the German hammer spring. HmM!

I can get a pretty good ratta-tat-tat going, and it’s fun as heck. I took out almost all the takeup & overtravel, and the trigger only moves an 1/8” of an inch — doesn’t preload or hang up on the sear and the safety engagement is excellent. Was thinking about posting a thread someday about how I did all that, but would have to shoot a bunch of pictures first for any of it to make sense.


Anyway, even with all that’s been done I think I’ve hit the wall tinkering with the MKE box — I’ve got an HK semi-box laying around, am gonna put that thing together sometime, though that’s gonna jack up the trigger overtravel since HK put the stop higher up in the box than MKE, so a redo will have to be done on the trigger part to get overtravel back where it was set with the MKE box.
 

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Discussion Starter #3
Interesting. Especially the take up and over travel adjustment. Would like to see/hear how you did this as improvements here will completely change how a trigger feels.
This pack is different to me because I've only worked on "traditional" modified semi packs, never auto packs. So the auto spring being original design and the pin hole being in the original location has me looking at a new learning curve. I'm chicken to mod the spring, a few years ago I tried to bend an auto spring into a semi configuration and the thing broke much easier than I figured it would. Since then I've only purchased semi only springs instead of making my own. Haven't even tweaked one for pull improvement.
I've read that RTG Parts has a semi spring without the roller that improves the pull but I've never seen or worked with one and doubt it will work in the MKE pack since it's a semi only spring.
Thanks for taking the time to post here, I appreciate it.
 

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Freefall, do you think you could take the slack out of the first stage on the standard trigger pack that comes w/ the MKE z5p or z5rs? I'm new to the platform and I haven't even gotten mine yet as I'm still overseas for another month.
 

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Interesting. Especially the take up and over travel adjustment.
That started out by just messing around, then I had to put some thought into how I was gonna do it without overheating everything or just blowing away the metal of the trigger, which is basically stamped sheet metal with a machined core for the sear to work off of.



In the pic above is an old HK trigger – set the MKE one aside, gonna keep that one stock – not very pretty, but this pic was taken while in-progress, so trigger hasn’t been cleaned up, faced off or whatnot. Was using a 6013 rod one-sixteenth of an inch in size (1/16”) – was like trying to weld the edge of a street sign with a toothpick, set on direct current, positive electrode (70% heat in the electrode, 30% in the work) , set below 40 amps. Had to do a bunch of jostling around on the amp setting to find a setting that I could deal with. There was no real welding to do, like running a bead, it was just a quick BZT!, and checking the progress. The 6013 was probably too aggressive, it was enthusiastic about penetrating, but I soldiered on with the settings & technique and got some results. When I did a billeted trigger, switched to a 7013 rod, which turned out to be a little harder to work with, since it was harder material and had to knock the flux ball off the electrode at every stroke to get any arc. I like the billet trigger a heap more just from the shape & feel – with the standard MKE/HKs felt like I was trying to shoot a Super Soaker.




This pic is a closer look at the action – on this particular trigger, nailed the takeup right off the bat, the overtravel took more work - had to keep building a little more material on that one initial bead without messing it up. Haven’t taken any measurements or the like with the HK box, but just by looking, will probably have to build that overtravel bead twice as high as it was for the MKE.
 

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Dont drop an MKE or POF pack into an SEF housing. If you move the selector to F, THE PACK WILL CAUSE THE GUN TO SLAM FIRE!!! The Turks failed to relocate the trigger stop pin to the proper semi-only position. I have heard that this has been corrected on the newer imports however I have not verified.
 

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They did not relocate the original sear pin. It's in the original location, and all they did was shave the sear down and remove the engagement surface from the hammer.

Thanks for posting this hkshooterusp, I've railed about this before.

I thought to replace it with a roller, as in the moved pin semi-auto designs, but that won't work.

Recontouring the sear such that it no longer touches the hammer, but still has the tail for the spring tab is the only way I can see unless you want to move the pin.
 

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Discussion Starter #9
Dont drop an MKE or POF pack into an SEF housing. If you move the selector to F, THE PACK WILL CAUSE THE GUN TO SLAM FIRE!!! The Turks failed to relocate the trigger stop pin to the proper semi-only position. I have heard that this has been corrected on the newer imports however I have not verified.
Thanks for speaking up, Joe. Good info. But you said Turks and mentioned POF. Did POF make the same error as the Turks then?
 

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They did not relocate the original sear pin. It's in the original location, and all they did was shave the sear down and remove the engagement surface from the hammer.

Thanks for posting this hkshooterusp, I've railed about this before.

I thought to replace it with a roller, as in the moved pin semi-auto designs, but that won't work.

Recontouring the sear such that it no longer touches the hammer, but still has the tail for the spring tab is the only way I can see unless you want to move the pin.
I forgot about this! It's bewildering that the ATF let this go when they have set a previous precedent for roller-lock semi-auto packs.


Thanks for speaking up, Joe. Good info. But you said Turks and mentioned POF. Did POF make the same error as the Turks then?
Yep, POF did (did not) the same.
 

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Discussion Starter #11
I forgot about this! It's bewildering that the ATF let this go when they have set a previous precedent for roller-lock semi-auto packs.




Yep, POF did (did not) the same.
Ok, cool.

I just checked my MKE pack and the trigger won't over travel and allow the rifle to slam fire. With the selector completely removed even. There's a big round block welded to the frame that stops the tail.
Have no idea how old or new this pack is, I got it used from the market place. But now after some thought I need to check my POF pack.


Sent from my SM-G920V using Tapatalk
 

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Ok, cool.

I just checked my MKE pack and the trigger won't over travel and allow the rifle to slam fire. With the selector completely removed even. There's a big round block welded to the frame that stops the tail.
Have no idea how old or new this pack is, I got it used from the market place. But now after some thought I need to check my POF pack.


Sent from my SM-G920V using Tapatalk
Good. I heard that they were going to address it. You just verified! :)

FYI--the block would be there regardless--it's the location of the block. f/a packs have the block higher, s/a pack have it slightly lower.

Cheers!
Joe
 

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Discussion Starter #13
And just checked my POF pack, just as you said, it will slam fire in an SEF housing with the selector in F. Bastards.

And I confirmed the MKE pack will not fit the POF housing without mods. The POF housing has a block welded in the front that won't allow an unmodified auto pack to fit and consequently the MKE pack with the auto sear pin in the original location won't fit either.
Now I have to decide if I want to mod the POF housing so it will accept the MKE pack so I can use the steel housing, or if I want to modify the MKE plastic housing to fit the rifle. Yeah, the hole for the shelf is too small in the MKE housing.
My goal was to replace the POF pack with a better quality and smoother operating pack but these bastardized parts aren't playing nice.


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And just checked my POF pack, just as you said, it will slam fire in an SEF housing with the selector in F. Bastards.

And I confirmed the MKE pack will not fit the POF housing without mods. The POF housing has a block welded in the front that won't allow an unmodified auto pack to fit and consequently the MKE pack with the auto sear pin in the original location won't fit either.
Now I have to decide if I want to mod the POF housing so it will accept the MKE pack so I can use the steel housing, or if I want to modify the MKE plastic housing to fit the rifle. Yeah, the hole for the shelf is too small in the MKE housing.
My goal was to replace the POF pack with a better quality and smoother operating pack but these bastardized parts aren't playing nice.


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You could also buy a new housing. Most of the time surplus MP5 housings are pretty expensive. But surplus G3 housings both metal and even sometimes plastic can be found pretty cheap. You will have to manually hack off the very end with the 2nd stock pin hole, but that's easy and other than that is a direct fit onto an MP5.

That's what I did for mine instead of modifying or hacking up my stock MKE pack. I wanted to replace the internals with all available US-made parts so I found a couple $5 metal G3 housings, a wood grip, and created a whole new trigger housing and pack. Cost me about $250 total for an entire by-the-parts complete lower housing/pack. If you just need a new housing you should still be able to find a surplus G3 one for <$20.
 

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Discussion Starter #15
Fitted the MKE pack and housing to the POF today. Yeah, fitted.
The hole in the front of the housing only needed lowered and opened a bit to fit the POF shelf. Took less than five minutes. The kicker came when I installed the pack and test fit the unit to the receiver. The pack fit up against the tabs on the receiver opening way too tightly. It took big pressure to even consider getting the unit pressed up against the receiver tight enough to install the butt stock, forget the pin.
After careful consideration I let the old but true mantra of "always modify the cheapest part" dictate my next move. Since this is a Turk pack and there are thousands of them out there, I decided to mod the pack frame vs filing on the receiver tabs.
Using a file I put about a .020 step in the pack frame when the tabs up front meet the frame and touched up the frame where the rear tabs meet with just a skimming, probably less than .010. Test fitting the unit to the receiver saw that with very minor pressure everything fit up nice and tight and the stock went on without trouble. Sweet!
It was now that I decided to message the rear stock pin hole a little. It had been somewhat bothersome to get in and out since the tube in the receiver is crooked just a few thou. A couple of minutes with a rat tail file and some polishing and the pin slips in and out nearly as easy as on an HK receiver.
After assembling the pack with my German ejector the pistol went back together like an HK should. A couple of loaded mags accompanied me and the gun to the back yard where the gun ran perfectly. Ejection was even better than with the doctored POF pack with HK ejector and ejection was distant and very consistent.
As seemingly crude as the MKE units can be sometimes, this trigger pack, even with it's left over auto parts, is an improvement over the POF piece that my gun came with. I like it and the plastic housing is a bit more comfortable on my middle finger where the trigger guard hits than the metal housing.
The gun is about to the point where I'm ready to refinish it now that all the fuss is done. Refinish. Reload. Enjoy.
 

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Discussion Starter #17
Glad to hear you got it running!

FYI, that pack is from a 2015 MKE, one of the recently imported ones.
Thanks!
Good to know about the make and it kind of confirms Joe's thoughts that later packs had the trigger stop corrected. We now know that sometime is 2015 the Turks fixed the error of in the trigger pack.
 

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Good. I heard that they were going to address it. You just verified! :)

FYI--the block would be there regardless--it's the location of the block. f/a packs have the block higher, s/a pack have it slightly lower.

Cheers!
Joe
How do we check to see if a MKE has these modifications? Can someone post a picture?

My Z-5RS was purchased in April, 2016. My trigger group is a mix of original MKE and US parts (trigger box, hammer, sear, trigger) for 922R compliance. Would using one of these SEF housings (HK Push Pin German SEF Navy Style Trigger Pack Housing) with a Z-5RS create the potential for a slam fire?




I'm essentially using this trigger pack...Zenith 922R Compliant Trigger Pack...

 

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New to posting and just looking to get some help. Found a thread about triggers and thought it might be a good place to start. I have a G3-sg1 trigger that I am converting to semi auto. I took a bunch of picture of the trigger pack before I pulled it apart but am unable to get it back together. I am looking for any and all help to get it back together. (Directions, descriptions, photos, schematis, diagrams)
 

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I have a few at home. Post up pics where you're stuck and I can compare. I have burst pack manuals, can't remember if I have them for the set trigger or not.
 
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