trigger location

[whitebear]

I am building a halfstock percussion rifle from mostly parts that are on hand.  I am wanting to use a single trigger that I already have #TR-ENG-T on tracks websight.  My question is what is the relation of the pivot pin to the sear bar, should they be close together or should the sear bar be closer to the back end of the trigger.  I intend to adjust the fit so that there is minimal travel between the trigger and the searbar.

I am using a siler small percussion lock, G.M. 13/16 X .45 X 36" barrel, german silver furniture, and a curly maple stock.  I don't know if any of this information will be helpfull but it doesn't hurt to have it.

Thanks for any information that I get and for all the good information in the past.

[Thom]

I have always felt that proper trigger
geometry is much overlooked and improper
geometry can greatly slow an action. I have built the triggers on
The three rifles that I have built.
I'm sure you will get some
Good advise and this will be an informative thread.

Thom

[curly]

The best single trigger location I've found to use is......1/4" to no more than 5/16" in distance from the center of the sear bar to the center of your trigger pivot pin, and about 1/4" above center. This set up will give you a very light pull. Works for me.

Curly

[ironwolf]

  It's a trade off.  The closer the pivot the lighter the pull, but the needed travel is increased.  The farther the pivot the travel is lessened but the force is increased.  It's a lever.  Recall your simple machines from grade school.
  It also helps if the pivot is above the sear/tricker contact point.

   Kevin W.

[Phillip Smith]

http://americanlongrifles.org/forum/index.php?topic=20490.0

This is something that you may find helpful.

Phillip

[Dphariss]

There is more BS concerning trigger pin location in relation to the sear than is necessary.
First the trigger needs to be placed so it does not make the gun look funny. IE screw up the lines.
The trigger pin needs to be at or a little above the sear bar and about 1/2" from the sear bar maybe as little as 3/8".
People who believe that the trigger needs to be pinned next to the sear bar have lost track of the idea of ADJUSTING THE PRESSURE needed to move the sear and through this adjust the trigger pull. This will produce a crisp trigger pull of as little as 8 ounces. Moving the pin close to the sear simply increases creep.
But it requires an understanding of the workings of the lock and that the sear spring is often far too stiff. Many times the spring is 50% or more of the resistance to the sears movement. If the sear will stay in the FC notch with no sear spring pressure, as it should, then the sear spring can be lightened. Its purpose after all is to POSITION the sear NOT hold in in the FC notch. The spring should be snappy and give a nice "click" as the lock is cocked, but need not be heavy to do this. If the trigger pull is still excessive then the sear nose and bearing surfaces of the tumbler need polishing and possibly stoning to refine the angles. If this is done properly it is possible to get a very nice SAFE trigger pull in the 3 pound range even if the pin is 3/4" from the sear bar. But most will not believe this since they have never had to adjusts a trigger pull on a rifle in which the pin is really too low and "too far foreward" and not changeable due to fixed design.
Most locks/firearms are made to be safe from liability, So the parts are made to be easily assembled and produce a secure hold on the FC notch. While its possible to produce a light trigger pull that is save but it takes a skilled worman and TIME and this adds expense. So the sear notch is deep and may have a "hook" to lock the sear in the full cock.
There are mistakes to avoid that I am not going to type out here.
The bottom line is to make sure that the gun will stand shocks and not "fall out of full cock". I use a small 6 or 10 oz dead blow mallet. If the gun will not stand 3 moderate whacks with the mallet and hold full cock its not safe.
And if in doubt don't mess with the lock unless you are willing to replace parts. A very little taken off in the wrong place will result in buying new parts.
Dan

[Stophel]

I agree.  The position of the trigger pin has little to do with weight, but everything to do with the creep or length of pull.  I always put mine at a half inch from the sear bar.  Moving it closer does not really "lighten" the pull, but makes it way longer.  Once I put a trigger in at 3/8", listening to all the advice I had been getting.  Well, it was a light pull (mostly thanks to the light springs), but MAN, when you pulled the trigger you wondered when it would ever let off!!!     So, I don't do that anymore!  I don't see how people get away with putting them even closer than that!

The sear spring (and whether or not you have proper angles on the sear and tumbler notch) is far more important to pull weight.

I've not gotten to take apart a whole lot of old guns, but of the ones I have, ALL of them have had triggers pinned at least a half inch.  Closer to 3/4"!!!  and they have HEAVY sear springs... I guess they just lived with heavy trigger pulls!   

[smylee grouch]

I try to get mine at or just above the sear and 3/8 inch back. It's worked well for me so far on about 20+ rifles.

[DaveP (UK)]

There are references here, and particularly on the thread linked above, to the importance of a well tuned lock to satisfactory trigger function.
I have somehow formed the impression that locks from the leading contemporary makers would be good to go as received. I'm happy to strip and reassemble but I didn't want to have to take a file to one just yet.
Is that realistic?

[Dphariss]

There are references here, and particularly on the thread linked above, to the importance of a well tuned lock to satisfactory trigger function.
I have somehow formed the impression that locks from the leading contemporary makers would be good to go as received. I'm happy to strip and reassemble but I didn't want to have to take a file to one just yet.
Is that realistic?

Stoning at least will be needed for a good single trigger in most cases some may require more...


Dan

[Pete G.]

Pinning a trigger in a low position results in the trigger that applies force not only in an upward vector (good), but also forward (bad). If the trigger pivot coincides with the sear pivot you won't have the problem of trying to force two parts under pressure to slide against each other.

[ken]

I prefer a single trigger to set triggers. Yes I have found that 3/8 th of an inch to Be the best for a light pull. Both for target and hunting. To solve the creep problem I cut the trigger bar at a angle or slant if you may. This has worked on numerous guns.    Ken

[whitebear]

Cutting the trigger at a slant or angle is discussed in "Recreating The American Longrifle" is this what you are referring to?  If so how do you judge the amount of angle that you cut.

[Nate McKenzie]

I like to flatten the top of the blade if its not already flat, then pin the trigger about 1/16in. below and behind the sear pivot. File angle on top of blade to nearly the same as the sear to adjust for little or no play. This way there is little or no sliding between blade and sear arm but I polish them both anyway.

[JDK]

Cutting the trigger at a slant or angle is discussed in "Recreating The American Longrifle" is this what you are referring to?  If so how do you judge the amount of angle that you cut.

I trim some off the top of the trigger leaving plenty of the flag then install and pin it with the lock out.  The trigger flag will be visible in the hole for the sear arm in the lock inlet.  I put some prussian blue transfer paste on the end of the sear arm and carefully attempt to install the lock...it won't of course, as the sear will hit the trigger's flag and the blue will transfer at the contact point.

I score a line under the mark through the hole with a scribe before I remove the trigger.  Remove the trigger, scribe the angled line on the flag, leaving meat around the pin hole and then cut/file it to the line.  Reinstall, try, remove to fine tune, repeat.  Polish and burnish the top of the flag when finished.  Harden if you feel it's necessary.

That's how I do it.  Enjoy, J.D.