• The Trigger Pull-Off - Part 2 (by Peter Laidler)

    The following article is published with the kind permission of Advisory Panel Member, Mr. Peter Laidler. On behalf of MILSURPS.COM members, we'd like to publicly thank him for his support of this forum, as well the broader Lee Enfield collector community in general.

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    "The Trigger Pull-Off"
    Part 2
    By Peter Laidler

    What we’re going to do is to set up a rifle as we would for an Armourers trade test or as the instructor teaching it to the class. By now, you’ll all have a perfectly set-up bolt that slides into the body and is clear of the sear. Next, we’re going to select a No1, a No4 Mk1 or a bog standard No5 because how the pull-off affects the No4 Mk1/2, 1/3 and 2 will become clear later. First, I want you to run a steel rule or straightedge along the top edge of the trigger-less trigger guard. It must be flat and not warped. Now, pace it into its recess in the fore-end and insert the rear trigger guard screw. The trigger guard should lay down flat. If it doesn’t, it tells me that the draws at the rear of the fore-end are too tight (unlikely with your original fore-end) OR that the wood in the trigger guard recess is too proud. Identify what the problem is and scrape it so that the trigger guard fits flat and square. Ok, so, if it is slightly raised at the front trigger guard screw (NO, NO, it’s NOT the king screw, it’s the SCREW, Front, trigger guard……….), by, say a 1/16th or 1/10th of an inch or so, what the heck but remember, the fore-end is secured by the front trigger guard screw and not the tension of a distorted trigger guard….., got that? After ensuring that the collar is a PERFECT fit and is nipped between the body, the trigger guard and that the fore-end is tight, fit the trigger guard and trigger. You also need to ensure that there is no undue slack between the trigger guard, the trigger axis pin and the trigger. The trigger axis pins do wear and form a shoulder along the shaft so watch out for this. If you do need a spare, then they’re readily available from the usual parts suppliers or, if you want to cheat, then just use a spare PIN, cap, fore-end or shank for any of the 4BA screws such as rear trigger guard or foresight protector screw or even a 4BA clearance drill at .144” or 9-SWG for you oldies

    Now test the action of the trigger as there is one thing you ought to be aware of. If the body is worn, then the bolt might be loose in an up and down way and this CAN affect the second pull-off. If this is the case in your rifle, adjust the pull-off when it is in its natural position and not under any other form of control, such as pressing down onto the top rear of the bolt. The trigger will give one of the following reactions.

    A crisp clean first pull of the trigger until it meets with a slight resistance, then a second squeeze, and almost without noticing it, the sear is drawn down another millionth of an inch and off she goes. Sheer poetry in motion, perfection and a first class trade test pass.

    You can have a long uninterrupted straight pull down and fire off the action. This is a first pull only (or FPO on the In-Inspection sheet)

    Or you can have the same again but heavier. This a second pull only (…yep, 2PO on the in-inspectors sheet)

    Or you can have a good clean first pull, then the resistance, then another long heavier pull then it’ll go off, well, whenever it feels like it. But YOU won’t know except that it’ll be ‘sometime………’ This is a ‘drag 2nd pull’

    2 - is caused by only the FIRST rib or bottom rounded rib of the trigger contacting the trigger flat of the sear

    3 - is caused by only the TOP or PULL-OFF rib of the trigger contacting the sear

    4 - the drag second pull is caused by the first rib being too low and it not drawing the sear down sufficiently before the top pull-off rib engages the sear

    You have to identify which of these is affecting YOUR rifle. If the pull off is as identified as 1, then go no further. It’s just practice and feel as to whether there is absolutely no drag on the second pull. When I was the snipers Armourer, I used to squeeze the trigger with another finger from the other hand between the back of the trigger and the guard. Just the slightest feel of resistance and then a click as it fired was good enough. If you do have the perfect pull-off, as in 1, then you must do the following to confirm it.

    After taking up the first and stopping at the second pull, release the trigger fully. The sear MUST resume its original raised position. In other words, the trigger and sear must reassert themselves

    If you have feature 2, it indicates that the rounded LOWER rib is too high and drawing the sear down off the cocking piece before the top bent comes into operation. So, you must carefully stone the bottom rib squarely, while retaining the rounded profile, a few .001” at a time. Use a micrometer from the rear….., you’ll soon start to take it down bit by bit. This is the best option, so go carefully because you’ll quickly find that you have shortened the first pull and have JUST started to get the second pull, which is JUST what you want and need. Now it’s a case of fine adjustment so that the second pull comes into operation as the sear is right at the bottom of the cocking piece.

    Option 3 is going to cost you because it indicates that a butcher has been at your rifle and has probably stoned away the lower trigger bent so that only the top, second rib is operating on the sear. You’ll actually see this by the shape of the trigger. I have to say that although we had this fault set up on out trade test and training school examples, I never ever saw it in service because such a butchered rifle/trigger couldn’t get past the system and no amount of warpage in the fore-end would cater for it. I suppose you could replicate it by bending the trigger guard, but you’d have to go some…………………………….

    Now to option 4. The most common, the drag 2nd pull. This is caused by an excessive TOP rib. Now, the first rib draws the sear down until the second rib meets it. Then the second rib takes over…., the trigger pressure increases but now, because the top rib is excessive, the sear is still too far from the lowest point of the sear bent of the cocking piece. So now, the sear is drawn further down the face of the cocking piece by the second rib before it fires off. This is the DRAG we refer to. And it’s something we definitely don’t want. Like option 2, this is relatively simple to cure, by carefully stoning down the TOP rib, a couple of thou’s at a time until you get to the all important perfect pull off.

    If you have a Mk1/2, a 1/3 or Mk2 rifle, then you can immediately SEE what’s going on because you can perform this task with the fore-end removed. But with the No1, No4 Mk1 and 1/1 and No5 you’ve just got to keep removing the trigger and trigger guard to carry out the minute adjustments. I use a micrometer when I’m doing or teaching the youngsters to do it and take off 1 or two thou at a time, measured from the flat at the rear of the trigger. This way you can maintain the radius and keep the bent square-on to the axis of the trigger. It’ll take a bit of practice but once you’ve mastered it, it’ll come naturally.

    Each Armourers shop had a big box of triggers, which, like bolt heads, might not be right for one rifle, might be almost or even perfect for another.

    As you can understand now, there has been some behind the scenes discussion among the more experienced forumers about whether it is permissible to bend the trigger guard to achieve the same aim of a perfect first and second pull. Well, whatever your views, you can only achieve it constantly in this way, that is by stoning the upper or lower trigger ribs. While you CAN bend or distort the trigger guard, just how much ‘bend’ do you put into it. And just how much ‘bend’ is acceptable? This is what the EMER, the Armourers bible says on the subject. ‘……….trigger guard is not distorted and seats evenly in the stock fore-end. Trigger guards will not be set in order adjust the pull-off’. Well, that’s pretty unambiguous………………….

    But as I always say, my experience in this field is limited and at the risk of upsetting some, I could be wrong.

    NOTE: This skeletonised rifle is in fact a previously damaged No4T. It appeared that this ‘rifle’ had never been finished as a ‘T’ as the front pad hole had not been drilled. During bead blasting after a hard life as a skeletonised rifle, it was established that the screw had sheared off and simply been made off level. Drilled out and extracted, it’s back to its former self. Waste not, want not as they say…

    (Click PIC to Enlarge)
    The action of the No4 Mk1 at rest. Note that the top, pull-off rib is resting on the sear. This is because the sear is depressed, held down by the fire-off cocking piece. The No1, 4 and 5 all use the same action.

    (Click PIC to Enlarge)

    The action cocked. Now, the BOTTOM, first pull rib is acting against the sear. Squeeze the trigger now and as the trigger rotates rotates under a weight of between 3 and 4 pounds, it’ll rotate the sear downwards, sliding it smoothly down the face of the sear until the upper rib of the trigger comes into contact with it. Then it’ll pause while the top rib takes over…………………

    (Click PIC to Enlarge)
    …..there you go, from the left side. The top rib has contacted the trigger bent of the sear. Now, all that is required is a slightly heavier pull – to between 5 and 6.6 pounds – watch the target, crosswire level, pointer upright and square on, slightly exhale………, then the last squeeze and the job is done.

    (Click PIC to Enlarge)
    Rifle cocked, but trigger released. Notice the sear nose half-way up the face of the cocking bent of the cocking piece.

    (Click PIC to Enlarge)
    Pictorially, this shows the trigger at the end of the first pull, both ribs touching the trigger bent or flat of the sear with the sear nose at the extreme edge of the cocking piece………, just ready for the off.

    (Click PIC to Enlarge)
    FIRED. Sear clear of the cocking piece, cocking piece forward, top trigger rib now touching the trigger bent or flat of the sear. The rifle is at rest. This is ‘THE FIRED POSITION’

    (Click PIC to Enlarge)
    As in PIC above, the trigger mechanism at rest

    (Click PIC to Enlarge)
    Armourers shops had a large amount of triggers in a box that they’d use in order to get the best, and often, perfect fit before resorting to stoning, I did hear that you could bend the sear nose to effect the perfect pull-off. Don’t bother lads, they’re hard and will snap if you try.

    Copyright ©2006 - 2009 by Peter Laidler and MILSURPS.COM

    Collector's Comments and Feedback:

    1. In addition to being a trained and highly experienced military "Armourer", Peter Laidler has authored two excellent books about the No.4(T) sniper rifles and their No.32 scopes. They are titled "An Armourer's Perspective: .303 No.4(T) Sniper Rifle", which he co-authored with Ian Skennerton and his own dedicated work, "Telescope Sighting No.32".

    If you're really interested in some in-depth learning about the No.4(T) sniper rifles and the No.32 series of scopes, their history, evolution, repair and adjustments for shooting, I'd highly recommend those two books, which are pictured below.
    ....... (Feedback by "Badger")

    (Click PIC to Enlarge)

    Note: The opinions expressed herein or statements made in this article are solely those of the author, and do not necessarily reflect the views of the Military Surplus Collectors Forums, or the ownership and moderation group of this site. MILSURPS.COM accepts no legal liability or responsibility for any claims made or opinions expressed herein. Also, please note that neither the author nor MILSURPS.COM recommends that any member of these forums, or a reader of this article, try this type of experimentation without the proper knowledge, equipment and training.
    This article was originally published in forum thread: "The Trigger Pull-Off" - Part 2 (by Peter Laidler) started by Badger View original post
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