Fluting my firing pin?

[BoydAllen]

On the bolt handle jump:
What you are probably seeing is the cocking piece hitting one side of the radius at the bottom of the cocking cam cut, in the back of the bolt body. If you pick up the bolt handle just a little and retest you may notice a difference. Typically this does not come into play when firing a live cartridge because the firing pin does not fall as far, because the primer stops it short of full extension beyond the bolt face. Sometimes cam notches are cut, or bolt handles attached, so that the non cocking side is too close to the side of the cocking piece. The side of the cocking piece will rub as it falls, and/or the nose of the cocking piece will hit one side of the radius at the bottom of the cut, when the rifle is dry fired with an empty chamber. I have seen articles about putting a shim in the bottom of the handle notch in the action body to remedy this, but before I did that I would make sure that there really is a problem when firing a live round.

 

[M-61]

If the fastest lock time possible was a crucial factor wouldn't electrically primed ammo have a firm foothold in at least bench shooting?

 

[butchlambert]

Yes Sir, but It may not be allowed under the rules.

 

[GSPV]

Faster lock time means zilch shooting on the bench. What matters is correct ignition.

You are looking for 18-20 thou of primer indentation.

Measure it by:

1. Prime a case
2. Point the muzzle in a safe direction.
3. With the case chambered, ever so gently close the bolt with the trigger pulled.
4. Measure the pin fall at the shroud with calipers.
5. Cock, then pop the primer.
6. Measure pin fall again.
7. The difference between 6 and 4 is the primer indentation.

If it is shallow, deep, or inconsistent, accuracy suffers.

 

[M-61]

Faster lock time means zilch shooting on the bench. What matters is correct ignition.

You are looking for 18-20 thou of primer indentation.

Measure it by:

1. Prime a case
2. Point the muzzle in a safe direction.
3. With the case chambered, ever so gently close the bolt with the trigger pulled.
4. Measure the pin fall at the shroud with calipers.
5. Cock, then pop the primer.
6. Measure pin fall again.
7. The difference between 6 and 4 is the primer indentation.

If it is shallow, deep, or inconsistent, accuracy suffers.

Interesting answer. If 'zilch' means "NOTHING" then I would assume with two rifles to choose from differing only in lock time you would not care which you chose. Your answer was quite complete and thorough however electrical priming will only be one depth (neither too shallow nor too deep)--only consistent.
The proir answer by butchlambert is probably what stops it.

 

[LHSmith]

Actually, current IBS Group short range rules allow the use of electric triggers from Heavy Bench through Sporter Class and likewise both Score classes (Hunter and Varmint Hunter are now combined).
I know of no one that uses them.

 

[butchlambert]

Last I heard and this was a couple years ago, guys I know that have the Remingtons couldn't find primers.

 

[GSPV]

In a Benchrest rifle, I certainly would not care about lock time. I care about correct and consistent ignition. I might opt for a rifle with slower lock time if it got that way via more mass and less spring or fall. Springs change over time, but mass never changes.

 

[butchlambert]

I like my BR rifle with the tungsten weight added to my firing pin.

 

[GSPV]

Btw, show me a stable supply of electric primers and match-proven data and I would be all over them. Unfortunately, such does not exist.

Lock time is meaningless in benchrest. There is so little movement in a bench setup that we sometimes shoot "head up". That is, we aim, then get totally off the gun and just watch the wind flags for the condition that we want to shoot.

 

[M-61]

In a Benchrest rifle, I certainly would not care about lock time. I care about correct and consistent ignition. I might opt for a rifle with slower lock time if it got that way via more mass and less spring or fall. Springs change over time, but mass never changes.

The ONE consistent thing ( for our purposes) is the speed of electricity. MASS does not change but its speed does(lube,temp, friction, wear,etc.) I have not seen any advertising for slower lock times so I'm not sure of the reasoning behind your choice there.
As far as availability and cost I was not speaking to those. I assume you don't approve of the lock time in a matchlock?LOL Reliability and consistency of electrical primers I do not think can be topped. I think the improvement of electrical over mechanical is there.....I don't by enough to make a difference but none-the-less it exists.

 

[Raythemanroe]

All I can figure on this is that few agree on a point of view here...I can't personally believe that slow lock times would make anything better assuming ignition wasn't a problem...I'm sure there is a fine line not to cross between ignition and speed, in my case I believe the stiff more consistent CS spring should and probably will make up for less mass weight...I like to shoot 3-D archery also and arrow weight is such a big argument, some people believe the lighter you are the better cause of flatter shooting while I have found that in some and most cases a mid weight arrow will retain it's speed better and handle the bows force (arrow spine) better..Meaning in some cases heavy is better, but for my case here I believe there is a middle ground to be had and if all else fails at least I have a space for crud to go (fluting)...

 

[Raythemanroe]

Just kidding on the crud, I keep my stuff clean..

 

[Raythemanroe]

I would like to comment on primer detonation, pin contact, and mass and all that...wouldn't it very by brand of primer? Softer primers like Winchester vs harder primers like CCI or wouldn't that make much of a difference? Also pin diameter?

 

[butchlambert]

I believe after reading all of this over a couple times, you need to do one of 2 things. Shoot a lot more with you have or buy another rifle. Firing pin mods won't help you enough that you would know it.

 

[Raythemanroe]

Butch I have other rifles and I am building a 300 win from a Stiller action..I just don't like to give up on things...Also if your using a Remington type action which I bet you are, you won't notice a big difference..Pick up a Ruger and you will understand it..slow like a Mauser...

 

[M-61]

I would like to comment on primer detonation, pin contact, and mass and all that...wouldn't it very by brand of primer? Softer primers like Winchester vs harder primers like CCI or wouldn't that make much of a difference? Also pin diameter?

First I agree with butchlambert..none of this makes a difference you will readily see, merely there possibly is a better way.
Finally (because I can't help it), varying primers,softer, harder,pin contact, pin diameter et al, makes NO difference with electrically primed. All they have to do is be electrically conductive and will ignite with unmatched consistency.

 

[Raythemanroe]

I gotta believe electric would be hands down better..

 

[Raythemanroe]

I believe ( tell me if I'm wrong) to reduce Jump you would have to reduce mass weight and to retain similar detonation you would need to speed up lock time ( stiffer spring)..I do wonder if recoil (primer ignition and powder) has some kind of counter action on any kind of jump...

 

[BoydAllen]

Some time ago, there was an article on this very subject. According to it, the lighter pin, combined with the heavier spring, gives about the same kinetic energy, but only about 60% of the momentum of the stock parts. I see less cross hair movement when dry firing with the light pin and heavier spring in my Viper, but I cannot prove that the difference shows up on the target. I have done what has been proposed here, and that is the reason that i counseled against it. It was an interesting experiment, but the result was inconclusive. I am more inclined to inquire about other things is someone is looking for smaller groups, as I listed above. Many times fellows seem to want to focus on one or two things, in what needs to be a total program, if consistently smaller groups are to be achieved. Sometimes they justify this with a small wallet group or two, but never with an agg, shot in imperfect conditions, at times that were not of their choosing throughout the day. Don't get me wrong, I have nothing against enjoying a rifle and shooter's best performance, but I do feel that the average of several consecutively shot groups is a better indicator.