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DST operation, firing when taking safety off after un-setting trigger

2K views 11 replies 3 participants last post by  Andyd 
#1 · (Edited)
Evening all,

Looking for some clarification on DST trigger operation on a 1518. Today while hunting I had an opportunity for a shot, set the trigger and the shot opportunity passed so no shot. I then un-set the trigger using the procedure below. After finishing the hunt I pointed the muzzle at the ground and pulled the safety off to open the bolt to remove the live round from the chamber. While moving the safety to the off position the rifle discharged. I thought I had bumped the trigger in this operation but then though no, the un-set trigger weight is 3.5 lbs and I know I did not bump it that hard (if at all).

After unloading I closed the bolt, set the trigger and with the safety on pulled the front trigger to un-set it. Loud click, should be unset, slowly eased the safety off and about half way to the off position the firing pin dropped with no manipulation of the trigger. Does it every time.

As received the set trigger pull was about 8.5 oz, a little light for me as I primarily hunt with it, so I raised the weight to approximately 10.5 oz. Passed the bump test with no problems.

Here is how I understood the operation of the Anchutz DST to work:

1. To fire unset, just pull the front trigger, breaks at around 3.5 lbs.

2. To set the trigger, pull the rear trigger, rear trigger will not fire the rifle, you hear a good click and now the front trigger is "set".

3. Once trigger is set, then front trigger is much lighter at the break, pull front trigger to fire rifle.

4. My understanding is that if you set the trigger but do not take the shot and you want to un-set the trigger to make it safer, then with the safety on you pull the front trigger, you will hear a loud click and the action will now be in the un-set mode and to set it again all you have to do is pull the rear trigger again.

From a safety point I always set the trigger with the safety on, and only take the safety off when ready to shoot.

I use the same process outlined above to un-set my CZ SST rifles and have never had an issue.

I had contacted another RFC member who I felt was pretty knowledgeable in Annie DST operation and asked for advice. He gave me the following procedure to un-set the DST:

1. Ensure rifle is on safe.

2. Hold rear trigger to the rear and keep it there.

3. While rear trigger is depressed, pull the front trigger and then ease off the pressure on the rear trigger, this will un-set the trigger mechanism.

I tried this on my unloaded rifle and it does work. BUT!

1. Need two hands to complete operation, seems very awkward.

2. When I first received my rifle I unset it by MY method and it did not fire when taking the safety off until today. Something seems to have changed.

3. Is there a mechanical reason WHY you cannot/should not unset the rifle with the front trigger?

Even if the above method is THE way to unset an Annie DST, I'm SURE that someone has pulled the front trigger by mistake once set with the safety on and I find it hard to believe the firing pin can be expected to fall while moving the safety to the off position.

Anyone have any input? I'm quite mechanically inclined and not afraid to dive into triggers (have in the past) but before doing so I like to arm myself with as much knowledge as possible to promote a positive outcome!

Thanks in advance for any and all advice!

Cheers!

Wade

Any advice or can you point me in the right direction as to who to talk to on RCF? I'm mechanically inclined and am not afraid of diving into the trigger. Just thought I would ask someone who has more knowledge than me to shorten the learning curve!

Thanks
 
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#3 ·
Interesting!

First of all thanks for posting the instruction manual. It is interesting in that the manual gives my method of un-setting as the first and primary method. Then gives the second method I was given. Yours works also. I like to unset with the safety on, just feel more comfortable that something will not get bumped that way.

Having said that the above instructions indicate there IS a problem as my rifle should not fire when taking the safety off after unsetting using my (the first approved method).

Again, anyone have any ideas as to the possible cause?

Thanks

Wade
 
#5 · (Edited)
Wade,

the method that I gave you is the method used by hunters; it is the quiet method.

I looked at my 64 action closely and what really puzzles me with your unwanted discharge is that the safety on the 64 action with the DST is only blocking the trigger and hooks into the bolt handle to lock the bolt against opening.

If the gun fires when taking the safety off, it means that after you pull the front trigger with the safety on, the rear trigger must still have the pressure of the pre-load on it. On top of the trigger unit are two blades, the left one is for the front trigger when it isn't set. When the trigger is set, then the bigger right blade is set down against the heavy weight of the big clip spring and hooks into the front trigger.
When the front trigger is pulled, the right blade is pushed up by spring pressure and hits the roller #5001 which trips the sear.

In the below photo you can see a keyhole in the upper assembly. When the safety is turned on, the safety goes forward into the elongated part and blocks the roller from going up to trip the sear.

When the adjustment screw is tightened, the left trigger blade will be raised but still be lower than the right blade. I don't see where this can be the cause but since I see no other probable cause, I would also recommend turning the adjustment screw out a 3/4 turn and try it again.

 
#6 ·
Andyd,

Thanks for the information, on the road right now, will take a close look at it this weekend and let you know what I find.

I can say that when I unset it using the front trigger it does make a loud click like you would expect when unsetting this way. Without looking at it is seems like the sear has been tripped and is being held by the safety from falling.

But I'm more of a visual than written person so I will have to put the ole' Mk 1 eyeball on it to get the operation all clearly understood in my mind!

I will provide feedback once I get a chance to look at it.

Thanks!

Wade
 
#7 ·
Haven't been able to provoke that behavior from my '18 either.

I also can't work out how it's happening - I can unset mine with the safety off and taking no particular care, without the hammer falling using the 'silent' technique.

I actually found that if I have even the most cursory hold on the rear trigger, when I release the front, the hammer doesn't drop - so much so that it's almost harder to set the rifle off from the set state with your forefinger on the rear trigger, than it is to unset it.

Clearly something amiss in your setup I'm afraid.
 
#9 ·
Figured it out...

I now have a 1518 and a 1418 and with the advantage of having two actions side by side I was able to figure out what was going on. Also helped that I worked on the trigger of the 1418 prior to this so that made me much more comfortable taking this one on.

At first thought it was related to the safety finger blocking the trigger cam. Tried gently bending it higher then lower, nope, that wasn't the culprit. Dang, thought I had it and an easy fix to boot!

Won't bore you with all the details but spent a LOT of time staring at it and running it through my head, pushing on this, pulling on that, making SURE I fully understood the triggers operation before proceeding.

Figured that if the strike of unsetting the trigger was moving the sear to the point of firing when the safety was rolled off I should be able to duplicate the condition with the action in the padded vise. On the DST rifles the triggers stay in the stock when the action is pulled but the main firing mechanism is mounted to the bottom of the action so you can "fire" it while in the vise.

To duplicate the condition of the "jar" from unsetting the trigger I tapped on the hardened roller with a delrin drift pin and a light hammer. Just gave it a light sharp tap like it would get from unsetting the trigger. Nada, could not duplicate the condition. WTH, can do it every time I put it back in the stock. Hmmmmn, it HAS to do whith the roller/sear engagement relationship...

The break came when I just firmly pushed down on the cam roller with my thumb while the safety was engaged, basically just for the hell of it. I felt a very light "tick" in my thumb, pushed the safety off and the FP dropped. Aaaah Ha! Now we are getting somewhere.

The other clue that fell into place is that this trigger (1518) was a lot crisper on the break than my 1418, what controls that to a great extent? The amount of sear engagement. I pulled the bolt and looked at how far the sear stuck up from the bottom of the action, significantly less than on the 1418, which means much less sear engagement, now we are making progress!

Removed the trigger adjusting screw and spring so I could lift up the trigger bar to examine the sear face. You could see that it was engaging on the very tip and it was a bit worn. There was enough engagement for regular operations but when unsetting the trigger the sear would slide down so the rounded portion at the tip was just hanging on. Further downward travel was blocked by the safety tab butting against the cam safety notch. As soon as the safety was pulled back out of the notch the sear would roll out the rest of the way and FP would drop.

Very nice bit of sleuthing if I do say so myself, but what to do about it? Can't magically make the sear grow longer so how can I make it stick up further? After much thought and studying could only come up with two options:

1. Modify the cam so it could roll farther in it's "rest" position which would allow the trigger bar to drop closer to the action and thereby making the sear set higher through the floor of the action.

Possible to do but very difficult. First, to do this mod would require the removal of the trigger bar from the action. On the 1418 I received a great tip on removing a slotted nut at the front of the trigger bar/rear of the mag well that would have made this easy. BUT on the 1518 (22WMR) the mag well is different and the trigger bar is attached by a slotted screw that is BURRIED in the back of the mag well under the mag release lever and spring. To get to it would have been an absolute PITA and I'm sure I would have bent something. Then if I had gotten it off filing down the cam where it bears on the trigger bar would also have been a PITA. So that option did not appeal to me.

2. The ONLY other way I could see to allow the sear to raise higher into the action would be to remove metal from the bottom of the action where the cam pivoted against it. Lower this area, cam will set lower, pulling the trigger bar down farther which will raise the sear higher in the action. This method also had the benefit that I could remove the trigger spring/stud and raise the trigger bar up on it's front pivot pin far enough to be able to work on the action itself. Just took some tape and spun a couple wraps around the trigger bar and the mag well and went to work.

Took my smallest triangular file and used it to remove metal where the cam pivot marks were located on the bottom of the action so no guess work there. The triangle file works nicely as you can have a fairly narrow file and it will be very stiff because of it's cross section. This is important as you need to make the cut flat all the way across the action so both sides of the cam bear evenly against the action when you're done.

Here is the "flat" I filed in the bottom of the action:



I then cold blued and oiled it:



This photo shows the relationship of the trigger bar, trigger cam and the sear located at the right end of the trigger bar. With the metal removed from under the cam it sets higher (in this picture) which will make the end of the trigger bar raise even more (distance/lever) thereby raising the sear higher in the action.



Using the 'Ole MK 1 eyeball and a set of digital calipers the best I can determine is that I raised the sear by about .015" to .020".

Before putting it back together I rotated the sear face out of the action and then hit it with my stone to restore the flat face all the way to the tip and then polished it with 1,500 emery paper backed by the stone.

Reinstalled the action in the stock and tried it out and now the FP will no longer drop after unsetting trigger and rolling safety off. Success!

The operation did not really alter the feel of the unset trigger pull so happy about that, for now just going to stick with the original trigger spring and let it go. May fiddle with it at a later date to try to lighten it some more, just want get out and enjoy it for now!

Why did this happen? Dunno! Maybe was that way from the factory or maybe someone did some shade tree GSing on it and filed the tip of the sear down to decrease the engagement and making the trigger crisper. Didn't look like it had been filed though, will never know for sure, just glad I was able to get it working!

Hope this may help someone else out there, sure appreciated everyone's input!

Cheers!

Wade
 
#10 ·
Wade,

I am not a friend of permanent alterations of a crucial gun part like the receiver. The sear protrusion of the 5056 and 5001 can be manipulated by changing the geometry of the bracket; if the tab in front is bent - or a washer added - so that the front end is lowered, the triggerplate will automatically pivot upwards and be raised. I would have rather shortened the two cams of the sear (part 85) than recontouring the receiver. A new trigger plate (part 79) wouldn't have been too hard to find, either.

Did you already download the manual from the Anschütz website? It is the one for Modell 1416 ST, 1516 ST 1966-01-01_DE
 
#11 ·
Andyd,

I was not excited about the prospect of removing the metal but from where I was standing that was preferred to trying to alter the trigger bar. Mess that up and I would have been well and truly hosed.

From what I understand you've been in this game a loooong time and have even been able to hunt (for Annies and parts!) in Europe and if I remember correctly you had stated your spare parts ben contained exactly ONE trigger bar so I did not believe those parts were available.

You have a pile of beautiful stutzen rifles (I feel like a Piker with just 2 compared to you and in reality I should feel like the Cock of the walk!) and have been at this game since Moby Dick was a minnow. I wanted to shoot this rifle in my lifetime, did not think the needed parts would be available. Will know better next time!

Thanks for the reminder on down loading the manuals, had not done that yet.

Cheers!

Wade
 
#12 ·
The trigger bracket of the 5056 and 5001 are the same with the difference only in the DST sear where the 5056 has the trigger bar.

I enjoy the quality of older firearms that are no longer made and have spare parts for pretty much all my guns, with the Anschutz rifles being among the less expensive ones.

If you send me your email, I can also send you the manual. It helps to use the correct name for each part, especially since there are so few informative posts about the DST and its operation.
 
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