Trigger/hammer for homebuilt?

[Third_Rail]

Hi all,

I'm looking to make a simple single shot rifle, but I can't seem to make a trigger and hammer work. I have access to a machine shop, so actually making the rest of the rifle isn't the hard part. Ordering from Midway or Brownells (or similar), what would you recommend for a trigger and hammer that could be used for a single shot rifle? I need to stay on the cheap side as I've not got much money.

Currently, I'm leaning toward buying an NEF trigger and hammer and going from there, but I'd love to hear everyone's experiences/suggestions first.

Also - if someone has parts that I could use (hammer, trigger) laying around and is feeling really giving, send me a PM. I'm always scrounging for the cash for these projects, and every bit helps.  :wink:

[Nobade]

I would recomment Frank DeHass's books on single shot rifles and actions. Study the drawings there and learn what is needed to make a hammer and trigger work. It's really not too complicated, but you need to understand what is happening first.

[Third_Rail]

I own his book "Mr. Single Shot's Book of Rifle Plans". I cannot, at all, make a trigger/hammer work for the life of me. Scavenging a hammer and trigger that already work, I built a simple single-shot .22, but it didn't work as well as I would've liked as it was a hammer/trigger from a centerfire.


I guess what I need is just a simple hammer/trigger combination, not like deHass' complicated sears, etc. More like a cheap derringer is a good guideline.

[gunnut69]

I don't understand the difficulty in making a hammer/trigger functional.  But the simplest compnents would likely come from a center hung hammer/trigger system, such as is found in a simple single shot break action shotgun.  These are simple hammers that are held back by the direct action of the trigger nose(trigger sear) on a notch on the circular portion of the hammer boss(hammer sear).  Both parts normally are pivoted on pins which retain them in the action and provide guidance for their rotational motions.. They are also cheap.. and available.

[Third_Rail]

I don't understand the difficulty in making a hammer/trigger functional.

Nor do I, considering I made a hook rifler and a few other neat tools. I can't wrap my mind around the angles, etc.

They are also cheap.. and available.

What brand/combination would you recommend, along with where I'd get it?


Thank you both for your input thus far, I really do appreciate it.



EDIT: Just to be clear on WHY I'm having the problem with making a trigger/hammer... I haven't been able to get the hammer and trigger from the Chicopee drawings traced and cut properly to actually work. I try to understand how the angles and surfaces work, and I believe I understand. The actual angles are just a bit tough for me to get, as is the spacing. I work best when I know what I'm doing to the nearest .001", not just a rough idea. This is why I think it may be best to just get whatever hammer and trigger you think I should, then copy and work from there.  :-)

[gunnut69]

I've never had that problem.  The surfaces that actually contact need to be a radial line from the center of the pivot pin of the part(hammer/trigger.  This precludes indue movement of the hammer as the trigger is pulled or the mainspring causing the trigger to be extruded or squirted out of the sear.  Ergonomics and the spacing of the pivot pins will generate the working lengths of the components.  I would think the H&R break action (now called NewEngland Arms) guns with the button release on the side of the hammer slot would be just fine..  They are available from GunPartsCorp..  I'll put a link at the bottom of this reply.  Be very cautious as the spacing of the pivots is crucial..

http://www.gunpartscorp.com/

[Third_Rail]

I think I may give making them another go, now that I have a slightly better description. Let me see if I have it right...

The thickness of the actual contact surfaces (the "sear surfaces"?) between the hammer and trigger are directly related to the spacing in the receiver? So if I were to take two random pieces of steel and put a hole in each, it would only be a matter of finding the right spacing apart from eachother. So a rough idea of what shape they should be is all I need....


Guess I really should've listened to deHaas when he said "don't worry about exact measurements of the trigger and hammer".  

[gunnut69]

Thickness is irrelavent.  The depth of the notch, from the outer edge to the bottom closest to the picot point is important.  This is adjusted to control creep in the trigger pull. There are norms for the size of a hammer and it must have sufficient energy to reliably detonate the prime via the firing pin.. This is of course a function of the rotating mass of the hammer and the spring tension applied(the latter translates into rotational speed).  Also it is better if the trigger has enough leverage to overcome the resistance of friction and spring tension to release the hammer.  Try drawing a simple outline of the receiver on paper and include the breach and using pieces of paper cut out 'hammers' and triggers.  Try fitting them and achieving an ergonomic trigger reach and a useable hammer/trigger sear interface.  One could also just draw it on paper and use the resulting drawings as a 'basic' template..  Good luck..

[Third_Rail]

I may be able to do it yet. What thickness of steel would you recommend for a first try? 1/4" or so cold rolled?


That'll be fun to cut out by hand.  :eek:

[gunnut69]

!/4 or perhaps 5/16 would give enough thickness..  The hammer spur can be left a bit thicker in height and hammered over a rod bar to increase the width to give a target type hammer spur. A tip might be to drill the hole for the pivot and scribe the circular base of the hammer while turning the piece around a pin.  This will ensure the round base of the hammer is concentric. Also drill holes at turning points and use a correctly sized hacksaw to cut the straight cuts.  Switch to a coping saw with a metal cutting blade fopr the curves only.  I would anneal the cold rolled to make it as soft as possible before attempting to cut it.  You'll be case hardening the part after it's complete.