Manual Reset Jewell Trigger Test

B

Bill Myers

Guest
I received the necessary parts to convert one of my Jewell triggers to a manual reset,A freind of mine has made a few for testing to see if the application has any merit,I installed the parts into a jewell trigger & installed it onto my Lawton action,it has a 6 PPC barrel.The trigger functions as before,although it does hit the primers harder.I will test the rifle tomorrow if i can get away,I have all my 200yd targets that i have been shooting while i have been testing my tuner design,so nothing will change but the weather & the ignition.I shot this Rifle in a 400 yd groundhog match on tuesday & i have the targets from 2,3 & 400 yds,its going to be very hard to better these targets,At 400 yds 1.1 group for 5 shots & this is with a stiff load of 322 & barts 68.. 200 yds was .310 & i moved the tuner before going to 300,I had all vertical.If this trigger is better ,i will know ,We will shoot again this tuesday,I do not really expect the ppc to really shoot well at 400,last week was probally a fluke.My tuner is working well with 322 ,133 is a bit more delicate on the conditions & favors rainy weather,Maybe i do not have it hot enough. Will advise on the results. BILL
 
Bill, is this manual reset like a two part trigger lever that can be used as a set or not-set?

What is its intended application or advantage?
 
Jerry The trigger modification is supposed to take the upward pressure off the bolt.BILL
 
I have to know.

Assuming the Cocking Piece is what exerts the upward force, how does the trigger eliminate this?? I can't quite get a picture in my mind what you have come up with.........jackie
 
I believe that there are two issues here. Some time ago, Bill Calfee wrote an article (that was published in PS) that described a test that he did with a bathroom scale on drill press. He used the scale to measure the amount of force needed to advance the firing pin/striker after the trigger had been released. The cause of this resistance is/was the shape of the top lever (that holds back the cocking piece) and the force applied to the system by the spring that resets it. A manual reset trigger has no reset spring, so when the trigger is pulled, the top lever drops out of the way.

Getting back to Bill's test, with one unnamed trigger there was a considerable shot to shot variation in the force needed for the cocking piece to over ride the top lever. It was Bill's opinion ( if I remember correctly) that these sort of inconsistencies would show up as significant differences in how the primer was struck and result in fliers on the target.

In addition to all of the above, he also modified triggers so that the interface between cocking piece and trigger was vertical so that the bolt would not be forced upward at the back by the combination of a non-perpendicular interface combined with the force of the cocked striker spring.

If the trigger used in this test does not have a modified cocking piece and top lever, differences in accuracy will be because of the absence of shot to shot differences in ignition, attributable to variations caused by the use of a trigger reset spring. If the trigger interface is not vertical, the bolt will still be forced up when in the cocked position. (I think:D)
 
Will this mod eliminate the damage sometimes caused to the Jewells when a primer is blanked?
 
If the trigger interface is not vertical, the bolt will still be forced up when in the cocked position. (I think)
Click to expand...
Unless Mr. Calfee is contemplating yet another rewrite of the current laws of physics, the cocking piece is still forced up with "vertical" engagement., just as soon as you pull the trigger.
 
Charles E said:
Unless Mr. Calfee is contemplating yet another rewrite of the current laws of physics, the cocking piece is still forced up with "vertical" engagement., just as soon as you pull the trigger.
Click to expand...

"A manual reset trigger has no reset spring, so when the trigger is pulled, the top lever drops out of the way"..............no reset spring=no upward force.................Don
 
Jay said:
Will this mod eliminate the damage sometimes caused to the Jewells when a primer is blanked?
Click to expand...

Ive seen the trigger damage but could never understand how firing pin blow back could cause damage to an uncocked trigger unless firing pin rebound after re-cocking takes place and breaks the sear, but what could possibly cause enough rebound force after re-cocking to cause breakage?

It would seem that a manual recock would prevent primer blanking damage, but I dont understand how it happens with the standard re-set, so who knows?........................Don
 
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Don,
I was referring to the cocked position, where the angled interface and striker spring tension will hold the back of the bolt up against the inside of the receiver in the rear bridge area, leaving the upper lug out of contact with its seat. I believe that Jerry Stiller looked at the probable post trigger pull bolt motion, starting with the above mentioned bolt position, and concluded that it wouldn't just fall into place, but cycle up and down repeatedly. Whether any of this matters, has, I believe, yet to be proven. It is my unstandering that Calfee's "relaxed bolt" concept calls for the bolt to stay on the floor of the action both before and during firing. To do this, he needed to do away with the angled interface. (I think:D) On the other hand, if there is enough time for the bolt to settle into proper bearing before significant thrust is applied to the bolt face, and vibration of its falling into place is sufficiently small so as not to influence accuracy…

Boyd
 
Don said:
"A manual reset trigger has no reset spring, so when the trigger is pulled, the top lever drops out of the way"..............no reset spring=no upward force.................Don
Click to expand...

Newton's Third Law: For every action, there is an equal and opposite reaction. If the lever drops, the the cocking piece must rise.
 
Manual reset jewell trigger test

Check out Kelbys new trigger He address this topic.
 
I've watched all the debates about trigger sears and relaxed bolts with great interest. I've known for several years now that the next accuracy break through would be in the ignition systems we use. In the custom actions we use, bolt/action lug misalignment is almost nonexsistant. It's such a small factor that I'm not sure we could test for it, much less say if you do "this", it will reduce your group size X%.

With that being said I think there's a lot of room for improvement in regards to the internal workings of the bolt and firing pin assembly. Custom actions today are so well made and so consistant, action to action, that it is hard to perceive subtle differences between them. But we all know they exist. We see rifles for sale by very good shooters who could not make them perform at a competitive level. We blame barrels, scopes, triggers and ourselves and finally the action. Then the rifle gets sent to a different zip code. Because the differences in custom action are so subtle, if all you use is custom actions you'll miss some of these differences. I build a little bit of everything here. I've trued and barreled literally hundreds of Remington 700's. Because of the vast differences in these actions you can pick up on the variations between actions. I can predict when one is going to be a good shooter and when one is going to be a cantankerous cuss to tune up. All I have to do is dry fire it several times. I believe the performance differences in actions comes from the ignition system. Inside the bolt, firing pin fit and contact points as it is guided forward. The fit of the firing pin in the bolt shroud, the alignment of the firing pin in the shroud and the alignmemt of the shroud in the bolt. How many different places are there in the ignition system for tolerances to stack up? Can this cause a problem? In my mind it can.

How can we improve it? I'm not 100% sure. I know what I'm doing here to alleviate some of the problems in Remingtons. I think this would carry over in to BR actions.

Here's a list of ideas. Anybody tried any of this?

1. Reduce metal to metal contact? Reduce preignition
vibrations.
2. Alginment of firing pin inside the bolt?
3. Rework the bolt shroud?
Either alignmemt and/or use of a different material.
4. Coating contact surfaces to reduce friction?
5. Any other ideas?????


Dave
 
I had Bob Brackney bushing a Remington bolt fireing pin hole and true the internal fireing pin. Due to a stupid mistake on my part.I can't say if this made a difference or not but it kept me from haveing to replace the bold.I do not believe any of the (new custom actions or bolts) needs these mods.changeing fireing pins, springs, shrouds is probably a waste of money and time.UNLESS they are worn out or broken. Expect a lot of comment


Richard
 
I have noticed

distinct wear marks on the top rear of my bolts caused by the trigger engagement kicking them up. This can't be a good thing, even if it isn't grossly harmful. It would seem to me that it wouldn't be any more difficult to make a 90* engagement than it is a 45* or whatever the angle is.
 
Pete

A lot of those marks come from lifting the bolt handle after firing. I agree that to sloopy a fit can cause problems but I'm discussing custom actions here. What can we improve on in the ignition system? If the clearence between the bolt and the action is that bad then that particular action would be considered for use.

Dave
 
Dave,

It would seem that good alignment of the striker throughout it's travel is the first "gotta have" parameter. If their is varying resistance (friction, bouncing, etc.) there just has to be inconsistent ignition.

I guess the second thing would be to reduce the friction as much as possible, which would let us get by with a weaker spring.

I think I picked up this notion from you (but you can correct me if I'm wrong) -- whenever there is a action that just won't seem to agg, or throws an occasional random shot, and the obvious culprits have been swapped out, (barrel, scope, etc.), the next place to look is in the striker system.
 
90 Vs 45 Dgs

The Swiss rifle Tanner has used this trigger system for years.Wih great sucess.The Anschutz triggers use the 90 also.This isn't a new thing ,some will say a better way.
 
Dave Tooley said:
Here's a list of ideas. Anybody tried any of this?

1. Reduce metal to metal contact? Reduce preignition
vibrations.
2. Alginment of firing pin inside the bolt?
3. Rework the bolt shroud?
Either alignmemt and/or use of a different material.
4. Coating contact surfaces to reduce friction?
5. Any other ideas?????
Dave
Click to expand...

Dave, one idea I think would be worthwhile would be the elimination of the conventional firing pin/spring assembly with an electronic striker assy. Imagine a conventional bolt with a small solenoid threaded into the bolt body using the bolt shroud threads. When released, the solenoids plunger would drive a very short firing pin tip through the normal firing pin hole. This small pin tip would be lightly spring loaded for retraction after being actuated. This type of firing pin has been around for many years in single shot rifles like the Browning B78 where it's activated by the falling hammer. The 'trigger' would simply be a switch mounted in the conventional position. For a power source, a normal 9 volt battery would seem to be the way to go...but maybe one of the coin type batteries would be a possibility?

A setup like this would allow the use of conventional primers, which was the major downfall of the Remington EtronX system. These rifles also had a pretty sophisticated electronic board to allow a functioning safety, a 'low battery' indicator, etc. None of this would be needed for our uses, of course.

The beauty of a system like this is that it could be a refit into existing actions and would use the original bolt.

Just my ideas for improvement on a windy South Dakota morning. :) -Al
 
Charles

Your correct. You got this idea from me several years ago. You know what I've been doing with Remingtons and I think I worked on your Panda firing pin assembly.

Al

A solenoid would work. Not sure everyone would want to carry a battery around with them. I know I would trip over the wires. There might be an issue with pierced primers with an unsupported firing pin in the hole unless the solenoid was energized for a specific period of time. Gets more complicated all the time.


I'm on my second cup of coffee and my brain has just kicked in. Savage has their floating bolt head, which works very well and is a simple way to solve several problems.

Question: why couldn't the shroud ( or part of it ) float? Then when the bolt is closed it is held/aligned in a percision recess/seat in the back of the action just prior to the cocking piece on the firing pin engaging the trigger sear. You would have a single guide bushing on the firing pin. You would still have the upward force but your guide bushing would hold everything in the same place shot to shot with no binding action on the firing pin. In a traditional bolt you have alignmemt issues with the fit of the shroud in the bolt body, issues with alignmemt of the hole in the shroud for the firing pin, then we put a load on that from one side and try and bend all of those pieces. Some actions do a better job than others at managing that force.


Another question: Has anyone out there had a rifle that would not shoot well and then tried a bolt from another rifle? If so, did you give it a fair chance at performing and what were your results?

Dave
 
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