Gunsmithing Trigger adjustment/cock on close

[hereinaz]

Any good videos or discussions on trigger adjustments for reducing or eliminating cock on close? Discussion on the handoff of the sear from the bolt body to the sear, especially in relation to the closing cams?
Bolt action gunsmithing books?

I have done searches and find lots of scattered discussion and lots of BS that I can't filter well with my knowledge.

I know trigger hangers come with different amounts and PTG made or makes a Rem 700 cocking piece with less cock on close. I know effort for bolt close can be reduced. I know that Zermatt will install a trigger and set it up if you send it to them. For bad stuff I know you can reduce pin fall, create situation where the sear doesn't pick up the cocking piece, make a mess of the interface between them, and others stuff I can't comprehend. That's not everything I have figured out, just trying to close knowledge gaps

I have a rudimentary understanding on the process as the bolt is closed, but want more understanding.

Explanation isn't necessary, but pointers where to look would be helpful.

 

[Hateca]

Remington is cocking on open not close. Bolt cocking piece and trigger sear engagement is on close. Not sure what you are trying to achieve.

 

[hereinaz]

Remington is cocking on open not close. Bolt cocking piece and trigger sear engagement is on close. Not sure what you are trying to achieve.

Yes, it cocks on open.

But, if the cocking piece is too long or trigger too far back (or both), then there can be a small amount of "cocking" when closing the bolt. At least a portion of that is avoidable, some is necessary. It can change the force needed to close the bolt handle significantly. As I said, there are adjustments for it, but I don't know enough.

Basically, the bolt cocking cams "cock" the firing pin back. The sear/cocking piece interface can be even further back relative to the position of the bolt after bolt lugs cam into place. The camming action of the bolt lugs are forced to pull the bolt forward while the firing pin is held back.

I will get video showing it on my Howa.

 

[mcfred]

Here's a Recent discussion on what I think you're shopping for.

Good luck.

 

[DAVETOOLEY]

Most of what people are feeling is the cocking piece rotating out of its notch on the rear of the bolt. Reduce the height of the bump and things feel much better. I go as far as changing the angle of the ramp at the same time. Just about the last thing I want is less firing pin fall.

 

[hereinaz]

Most of what people are feeling is the cocking piece rotating out of its notch on the rear of the bolt. Reduce the height of the bump and things feel much better. I go as far as changing the angle of the ramp at the same time. Just about the last thing I want is less firing pin fall.

Thank you. I did change the notch angle, flattening it out some. Now, it is barely perceptible when it comes out as the bolt rotates, but when the bolt is removed the cocking piece won't slip out of the notch. That change already made a big difference. Your point about changing the ramp angle was my question. Now that I have changed the notch, I have more room to reduce the angle of the cocking ramp.

Which ramp angle do you change? Are you changing the angle of the the cocking ramp? That is actually one of my specific questions, is whether to create a longer and less steep "run" up the ramp to reduce the force necessary to cock the firing pin. I could reduce the angle by pushing the cocking ramp closer to the notch. That would spread the cocking force over more of the rotation of the bolt.

Your warning about reducing pin fall is another of my questions/concerns. I am only doing this on my factory action that I picked up for $250 bucks. I hope that the margin of error built into a factory action is big enough so that there is still plenty of power for ignition with what I have reduced pin fall. I picked up a spare bolt, so I have replacement parts when I screw up, hahaha.

This isn't anything more than a learning project. I shoot unadulterated custom actions for matches and hunting. The cost of ruining parts here as I explore is an education, cause I can't make it to a gunsmithing school...

(I like my face and fingers, a lot. I am very, very, very cautious.Safety being paramount, there are absolutely things that I will not mess with and I try to ask questions to find things I don't even know to ask. If anyone wants to tell me how I am crazy and how I will blow myself up, feel free, but be as specific as possible, lol.)

 

[hereinaz]

Here's a Recent discussion on what I think you're shopping for.

Good luck.

Hadn't seen that specific one, thanks. It does add a little to what I am working through in my pea sized brain.