simple trigger spring

[gumboman]

My current build project is a flintlock fowling piece. On this build I used a simple trigger assembly with trigger and bar in one unit. This was my first build using a simple trigger, having used set triggers exclusively in the past.

Installing and tuning this trigger was a challenge and more difficult than I had imagined. But in the end it is working satisfactorily with a nice pull force for a fowling piece. My only concern is that there is a lot of slop in the trigger. Not only is there a lot of side to side play in the trigger because of an excessively large slot for the trigger shoe in the trigger plate,  there is also a lot of slack to take up in the trigger shoe travel when the lock is at full cock and before the trigger bar makes contact with the lock sear bar.

I would like to add a light spring to the trigger to take up this slack. But I need some help with ideas on how to accomplish this. A tutorial would be best. I have searched the forum for information on this but had no luck in finding one. Can anyone provide assistance with this?

Thank you.

[davec2]

Gumboman,

This is a repeat of something I posted a while back:

I have been working on several more guns, rather sporadically, but did something last evening that may be of some interest.  One of my pet peeves is a trigger that rattles.  A second preference (not really a peeve) is that I don't like to pin a trigger through wood.  I know it will probably out last me by a couple of hundred years, but then again, I am an engineer and pinning a trigger through steel or brass has always seemed like a better idea.

In regards to the trigger rattling, I always had a $#*! of a time getting the trigger / sear engagement just right so that there was no rattle to the trigger at some point in any of the uncocked, half cock, full cock positions.  So, some time ago, I started putting a leaf spring under the trigger bar to lightly keep the trigger in contact with the sear at all times.  Works great, but it does take some additional parts as well as excavating additional wood in the trigger mortice to allow the spring to function properly.  Here is what the spring arrangement looks like..





The beauty of this arrangement is that no matter where the sear ends up in each of its three positions (uncocked, half cock, full cock), the trigger stays in contact with it and will not rattle.

However, last evening, while working on a Chambers English rifle, I made a few modifications.  First, to avoid pinning the trigger through wood, I bent a 1/16" piece of mild steel and silver brazed it to the trigger plate.  Second, I had intended to place another leaf spring under the trigger to stop the rattle, but the trigger plate is really too short to do that.   The sear on the Chambers lock stays relatively in the same position when at any of the three lock positions, so I didn't need quite the range of motion.  Instead of the spring, I made and installed a 5-40 screw through the front face of the steel trigger pivot support and used it to push the trigger bar into light contact with the sear.  Works great and is simpler than the leaf spring arrangement.  No rattle in any position.

Here is the link to the whole post so you can read other's responses as well:

http://americanlongrifles.org/forum/index.php?topic=34071.0

[Dave B]

Here is another example of a way to do it I found a picture of. This solves rattle but not long creep to the sear contact point. I like dave2 first trigger listed. It keeps it the trigger against the sear and prevents rattling.

[gumboman]

Davec2,
Thanks for the info. There is no substitute for pictures. Your solutions are easy and simple. I like simple. The leaf spring is probably the route I will take.

DaveB, thanks for your picture also. Another simple leaf spring.

Gumboman

[Bob Roller]

Here is another example of a way to do it I found a picture of. This solves rattle but not long creep to the sear contact point. I like dave2 first trigger listed. It keeps it the trigger against the sear and prevents rattling.

Trigger anti rattle springs are common on the high quality English rifles
and are made to put a light upward pressure of the trigger release bar against the sear.
Hold the trigger forward on one the guns equipped with a high quality lock like the 4
screw locks we've been discussing here and you'll hear two clicks that are really pronounced.

Bob Roller

[Pete G.]

You could also make another trigger plate. Make the slot narrow enough to stop the sideways play and very carefully fit the front end of the slot to stop the trigger from going so far forward.

[Hungry Horse]

 In my opinion the first trigger pictured has its pivot point too low, giving you no mechanical advantage. This is what's wrong with most commercially produced simple triggers. The others pictured are much better, in my opinion.

   Hungry Horse

[Jerry V Lape]

You can take the side to side slop out of the trigger by soldering a pair of small metal shoulder on the inside of the trigger plate to create a tighter slot for it. 

[Acer Saccharum]

Often a pinned trigger unit doesn't have the pivot pin high enough for good trigger pull. If the pivot is low, there will be more squeeze needed to trip the lock. The closer you can get the trigger pivot to the height of the sear pivot, the better.

Davec2's custom high pinned trigger is ideal.

[davec2]

Dave B.....I like the rivet instead of the screw I used.  Next time, I will use a rivet.

P.S.  I agree about the higher trigger pivot being better.  However, I haven't measured the trigger pull on both rifles to compare but I haven't noticed any appreciable difference while shooting them.  Then again, I'm not a big one for picking the fly $#@* out of the pepper......

[cmac]

You could also add a small screw to the bottom of the trigger plate making contact with the tail end of the trigger bar(similar to an adjustment screw on double set triggers).

[petera]

Hello,  All of the posts above are OK, but far too elaborate.  I started before anybody ever thought of casting triggers - we all made our own.  The breakthrough came when Jim Chambers produced his first lock with the one position sear!  IE, the sear bar is in the same position at rest, half, and full cock.  Having established that, you can easily make your own trigger plate, then forge a trigger and file fit it into the slot you made, so you don't have any side to side slop.  I call this the modern trigger, and I discuss it extensively in my book, which you can order from my website:  wwwgunsmithofgrenvillecounty.com, or from Track of the Wolf.  I understand there are not that many copies left......  Regards,   Peter A. Alexander

[Kingsburyarms]

Peter - Fantastic book - Thank you - I use it as a reference all the time - My trigger plate for the Chambers lock actually has a hole drilled in the plate with a brass bushing - 0 play, 0 pressure on the sear at any position, and 0 trigger "slop" but a nice smooth "snap" of the trigger at full cock, and absolutely no false starts at half cock. It may be from my centerfire days, but this design for the trigger follows the trigger sear action and is tight and efficient.  I did not want to have a "false pull" or to build in a space to take up the distance between the trigger plate and the sear.

Again - Great book -

Jon

[M. E. Pering]

If you are looking for a clear and concise discussion of simple trigger/sear geometry, Peter's book, pp. 192-194 can't be beat.  An excellent all-around book on the subject of gun building, Period.

One solution to correct the side-to-side play is to cut a couple of brass washers to go on both sides of the trigger bar.  The use of two will keep the trigger centered in the slot.  As far as the slop in the pull goes, one way you could correct this is to find a piece of steel the same thickness as your trigger bar, and silver solder it on top of the trigger bar.  Then, trim it down until you have almost no trigger travel.  I say almost, because there should be a tiny bit to accommodate temperature variations.

But before I did any of this I think I would make sure your lock is indeed a one position sear lock.  If not, I would correct this first.

Matt