View Full Version : I tried the hk LEM trigger

06-29-09, 23:55
and I like it quite a bit. Does anyone else make a trigger like this besides HK??

06-30-09, 00:42
Search the site for SIG DAK. There have been a couple of long strings comparing the DAK and the LEM. Similar, comparable, they are. The same they are not. Todd can give an in-depth technical analysis/comparison of both. Glad to hear that you like the LEM. Your money wouldn't be wasted if you buy an HK.

06-30-09, 09:00
The Para LDA is also similar, though I wouldn't recommend a Para for anything serious.

From this thread: (http://m4carbine.net/showthread.php?t=30461)

sigmundsauer has a great deal of experience with the LEM compared to me, so hopefully he'll chime in.


The HK LEM is basically artifice. It uses a two-piece hammer, one part internal and one part external. When the slide is racked (loading the gun or during the firing cycle), the mainspring is compressed and kept in place as with any single action mechanism. However, the external part of the hammer moves fully forward and so does the trigger. In essence you have a cocked pistol that doesn't look cocked.

The first shot is long like a traditional double action pull, but it's not any heavier than subsequent trigger pulls. The reset is certainly longer than most striker-fired guns or a 1911, but it's only about a third of the total trigger travel arc. Three different configurations are available:

V1: nominal 4.5# trigger pull; uses standard trigger return spring and standard firing pin block spring ... this is essentially the standard P30 SA trigger pull from the DA/SA variant

V2: nominal 7.3# trigger pull; uses extra strength trigger return spring and extra strength firing pin block spring ... the one example I have measured 7# 10oz out of the box and has dropped to 7# 8oz after 1,000 rounds

V4: nominal 6.1# trigger pull; uses the extra strength trigger return spring but a standard firing pin block spring ... for reasons explained below, I believe this is probably the best option

The only one I'm even marginally familiar with is the V4. The extra strength trigger return spring plays a tremendous role in counteracting the long reset. Obviously, it's the speed at which you manipulate the trigger rather than simply the distance which determines how fast your next shot will discharge. While moving a longer distance would seem slower, the stronger trigger return spring literally slams the trigger to the reset point faster than you could move your finger alone. Will it be as fast for blind "for the fun of it" rapid fire? Probably not. But I was pulling .20 splits give or take a couple hundredths after just a few boxes of ammo.

The extra power firing pin block spring serves no purpose but to increase the trigger pull weight, so I'm planning on replacing mine with the lighter one to get about a 6# trigger pull, which I find is close to ideal for a practical gun.


While my experience with the LEM is limited, my use of the DAK is extensive. In fact, I was the first person in the US (and probably in the world) to put one through its paces as a dedicated high-level training gun for many months when it was first imported. For quite a while, I probably had fired more rounds through a DAK than anyone outside a test range. I even wrote the lesson plan & taught SIG's first DAK transition class (for a large federal agency).

The SIG DAK is a genuine Double Action Only design and (prior to the SIG P250) had probably the lightest true DAO trigger pull on the market. Unlike the LEM, when the SIG DAK is at rest, the mainspring is not compressed any more than it would be in a decocked DA/SA SIG. The lighter trigger pull is achieved solely through changes to the trigger bar and some other internal parts which allow greater leverage.

When it was first released, the DAK had a nominal trigger pull of three kilos (6.6#). However, it never really quite worked out that way. For example, when we submitted the guns to DHS/ICE for testing in 2004, we called it a 7.2# trigger pull.

Because the size of the gun determines how long the trigger bar can be and thus how much leverage you can achieve, the P229 trigger was always a little heavier than the P226 by one quarter to one half a pound. The P239 DAK, being so short, has a trigger pull almost identical to the standard DA stroke for that gun. And the P220, which uses different internal dimensions, is about the same as the P229. Then, after a couple years on the market, it was determined that the DAK struggled with non-toxic primers. So a new spring, indicated by red paint, was introduced to provide a stronger primer strike. In my experience, the typical DAK trigger right now is around 7.5# +/- half a pound.

Then there is the reset. The DAK does not use a rebounding hammer like a standard (DA/SA) SIG. Therefore, it relies on the slide cycling to place the gun in what SIG calls the 'safety notch' or firing position. In order to provide restrike capability -- which SIG considers a worthwhile feature for a combat gun -- the DAK needed a way to cock the trigger when it was not in the safety notch position. The result is that, instead of being a simple "true" DAO with a full length reset, there is also an intermediate reset on a DAK. This intermediate reset, which does not benefit from the full leverage of the modified DAK mechanism, is about 2# heavier than the ordinary trigger pull. So you can either release the trigger all the way out (like a DA revolver) and get that same ~7.5# trigger pull, or you can reset it half way and get ~9.5# trigger pull on follow up shots.

In my experience, releasing the trigger all the way forward makes for much better results. In fact, I taught -- and convinced many people at SIG -- that the "intermediate" reset was really just there to save you if you short stroked the trigger ... while you should let the trigger all the way forward, the gun would protect you from yourself if you didn't. It sounded very tactical. But eventually people started to complain about how long the reset was and SIG changed course, instead saying that it was simply the shooter's choice as to which reset he should use. Last I knew, the SIG Academy taught folks to use the shorter intermediate reset.


Both actions are very smooth and manageable from a marksmanship standpoint so long as you do not try to anticipate the shot (which can take some getting used to for Glock & 1911 shooters).

Because the trigger on the DAK & LEM will move all the way forward between shots if you let it, you never run the risk of losing contact with the trigger between shots. This means much less chance of slapping the trigger when shooting at maximum speed. So for example, while my splits were a little slower with the DAK than with a DA/SA SIG (especially using the Short Reset Trigger version), I was much less likely to throw a shot with the DAK.

The LEM wins for me because of the reset. I can use a "short" (relatively speaking) reset while keeping a true consistent trigger pull from shot to shot. Whereas the DAK is like shooting a DA revolver (not counting the intermediate reset), the LEM is much more like a 2-stage AR trigger ... a comparison I stole from sigmundsauer, truth be told. The LEM also has the option for the extra strength trigger return spring, which further enhances the reset and resultant speed.

06-30-09, 12:23
Interesting... That was pretty detailed. Thanks for that writeup Todd.

06-30-09, 19:56
I have a P2000 setup with a V4 trigger as described by Todd with one exception.

In addition to replacing the firing pin block spring I also replaced the standard 14lb. mainspring with a 12lb. reduced power mainspring from Wolff. This drops the LEM pull down to just over 5 1/2 lbs but does wonders for the true double-action pull if the action should default to it after not fire a round on the first hammer strike.

This was done primarily because my wife has very small hands and arthritis such that she could not physically pull the trigger in true double-action mode (it was off the scale but my guess was 18-20lbs). Now it is at about 13lbs. I am not positive as the scale I borrowed tops out at 12 lbs but it did not take much more than that.

07-04-09, 19:03
I like the LEM a lot. I used to really like the DAK but found I had to shoot DAK pistols all the time to stay proficient with it. Every time I switched around it fouled me up.

07-04-09, 19:08
Welcome to my world. I carry a P2000SK as a daily and off duty carry and a DAK for heavy service. I hate switching between the two. Hopefully P2000's will be on our POW list soon and I can ditch the DAK.