[Freefall]

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.

 

[Freefall]

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.