Fireing pin "bounce" ?

J

jGEE

Guest
What is it?

I read about firing pin bounce -I'm thinking just like it sounds, The pin hits the rim on a rimfire cartridge -bounces back and hits again, causing unnecessary vibrations.

How can you tell if you have "firing pin bounce"? Is it an educated guess or something you can measure or some kind of "sign" that lets you know.

Has anyone changed up their firing pin and recorded improved scores they can attribute to a fireing pin modification.

I would appreciate any thoughts on this subject. thanks joe:)
 
jGEE said:
What is it?

I read about firing pin bounce -I'm thinking just like it sounds, The pin hits the rim on a rimfire cartridge -bounces back and hits again, causing unnecessary vibrations.

How can you tell if you have "firing pin bounce"? Is it an educated guess or something you can measure or some kind of "sign" that lets you know.

Has anyone changed up their firing pin and recorded improved scores they can attribute to a fireing pin modification.

I would appreciate any thoughts on this subject. thanks joe:)
Click to expand...

Joe,
Either you have a short memory or you are trying to be a 'funny person'.
D R
 
D R Greysun said:
Joe,
Either you have a short memory or you are trying to be a 'funny person'.
D R
Click to expand...

i have a short memory on some things, i seem to remember numbers pretty good...... no joke. But it shouldn't be so short as to forget a thread on firing pin bounce, especially if i posted in it. If we just went over this boy am i in trouble.

Can you post a link to the thread and i will delete this one.
joe:)

Mr Greysun i think i figured out your post. maybe your referring to the same question i asked yesterday in anotehr thread. That thread is Mr. Al's thread- he asked about stopping the f pin. Didn't mention bounce, maybe thas what he was referring to i don't know.

I know a lot of times if i ask a question in another thread it gets unanswered. I know if i ask more than 1 question in a thread one will be ignored and off goes the thread in a different direction, that's just the nature of massage boards.

Firing pin bounce is important enough to me to ask the "bounce" question in it's own thread -not 2 questions not 3 questions, very specific just 1 question... like always someone asks a question and off goes a comment by a "funny person", lol.... it's all good i just want to learn. joe:)
 
Last edited by a moderator:
JGEE asked: How can you tell if you have "firing pin bounce"? Is it an educated guess or something you can measure or some kind of "sign" that lets you know.
Certainly you are going to get guesses, calculations, and "signs" on what takes place. Which are you interested in and which do you think is most important?
 
pacecil said:
JGEE asked:
Certainly you are going to get guesses, calculations, and "signs" on what takes place. Which are you interested in and which do you think is most important?
Click to expand...

the target
joe:)
 
jGEE
The ones I have seen that had double bounce had a bit larger indent than the pin head.
The indent may not have clean edges, more rounded edges. I'm not sure if this is always true. I understand the double bounce is a No-No.

Fred K
 
I do not profess to being the sharpest crayon in the box, but with the power of these firing pin springs and the brass case head, can you maybe tell me, how the firing pin is going to "bounce". I would think that it would take an extremely weak or broken spring to allow the firing pin to bounce back from a soft brass case rim..

Dave
 
Dave
You might want to check on some of Calfee's writings (PS Mag) on this subject. Guess he says it can.
Fred K
 
jGEE said:
What is it?

I read about firing pin bounce -I'm thinking just like it sounds, The pin hits the rim on a rimfire cartridge -bounces back and hits again, causing unnecessary vibrations.

How can you tell if you have "firing pin bounce"? Is it an educated guess or something you can measure or some kind of "sign" that lets you know.

Has anyone changed up their firing pin and recorded improved scores they can attribute to a fireing pin modification.

I would appreciate any thoughts on this subject. thanks joe:)
Click to expand...

Joe, Bill Calfee stated in one of his articles in Precision Shooting that the firing pin can bounce if it is not shaped correctly. It needs to be shaped where it does not strike the rim being supported by the back edge of the chamber. That also causes vibrations in the barrel. Bill further stated that the firing pin needs to be polished or it would bounce when it hit the brass case. It would probably be best to find the article, I just hit the hi parts of the article. Joe , next time you have a question call or email. I promise I won't call you a name, make fun of you, or tell you , you are full of poop , for asking a question,
 
Joe,

You got me to thinking about this, for I'm aware of a case last year where one of the top shooter's had an issue with the firing pin.

When ones rifle is shooting to their expectations keep a few boxes of the same ammo, this is the control of the brass/shell etc.... and keep a few spent shells. A couple of ways one could do this is every few months, or if the rifle doesn't seem to be working, fire a few rounds from the control ammo and check the shells against the ones when it was working good. If a difference is noticed in the strike indention then they may be on to the problem.

Keep'em coming for I enjoy the post that makes me think about the technical end of the game.

Les
 
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Fred K said:
Dave
You might want to check on some of Calfee's writings (PS Mag) on this subject. Guess he says it can.
Fred K
Click to expand...

Mr. k, i grabbed my magnifier whern i read your post! I'll keep a closer eye on spent cases!

Joe , next time you have a question call or email.
Click to expand...

Mr. James it's an Honor having you post with us again! Your past comments about firing pin bounce stuck in my head and i have been wondering for a while now.

I appreciate everyone's comments thanks joe :)
 
jGEE said:
i have a short memory on some things, i seem to remember numbers pretty good...... no joke. But it shouldn't be so short as to forget a thread on firing pin bounce, especially if i posted in it. If we just went over this boy am i in trouble.

Can you post a link to the thread and i will delete this one.
joe:)

Mr Greysun i think i figured out your post. maybe your referring to the same question i asked yesterday in anotehr thread. That thread is Mr. Al's thread- he asked about stopping the f pin. Didn't mention bounce, maybe thas what he was referring to i don't know.

I know a lot of times if i ask a question in another thread it gets unanswered. I know if i ask more than 1 question in a thread one will be ignored and off goes the thread in a different direction, that's just the nature of massage boards.

Firing pin bounce is important enough to me to ask the "bounce" question in it's own thread -not 2 questions not 3 questions, very specific just 1 question... like always someone asks a question and off goes a comment by a "funny person", lol.... it's all good i just want to learn. joe:)
Click to expand...

Actually Joe, I was referring to a post (or group of posts) by 'Kathy'. Not so long ago and now it seems lost forever. Shame too, all the 'funny people' crap, needed to wade through to find a bit of useful information. So, in answer to your question, Mr. Calfee has very strongly feeling about firing pins and their interaction with regard to rim-fire accuracy. Be it bounce, weight, lock time, et all. I believe Mr. Calfee verifies the performance at the target.

D R
 
D R Greysun said:
Actually Joe, I was referring to a post (or group of posts) by 'Kathy'. Not so long ago and now it seems lost forever. Shame too, all the 'funny people' crap, needed to wade through to find a bit of useful information. So, in answer to your question, Mr. Calfee has very strongly feeling about firing pins and their interaction with regard to rim-fire accuracy. Be it bounce, weight, lock time, et all. I believe Mr. Calfee verifies the performance at the target.

D R
Click to expand...

Mr. Greysun it is unbecoming for a grown man to keep crying over "spilt milk". Me and i suspect a bunch more newbies missed "yesterday". I guess if we could send everyone back issues of Precision Shooter we could just turn off this web site. joe:)
 
jGee
I think you might be able to get back issues of PS. I think I can dig up the PS that covered the correct pin shape. Do you want to know which issue ?
Fred K
 
Thanks everyone for the valuable info.... It just seems to me everyone has excepted 'firing pin bounce without a way to determine if it exists.
mr Fred k has a good answer:
jGEE
The ones I have seen that had double bounce had a bit larger indent than the pin head.
The indent may not have clean edges, more rounded edges. I'm not sure if this is always true. I understand the double bounce is a No-No.

Fred K
Click to expand...

The bullet flight time may be fast enough it clears the bbl before the firing pin has time to fall again -making firing pin bounce a moot point. If the bounce does strike the case before the bullet leaves the bbl. that would be pretty dang fast. if it does double strike before bullet exit -wouldn't that be a continuous vibration? If not you can get 'several vibrations from just one pin strike, first vibration when you strile the rim, second vibration when you got past the rim and 3rd viberation when the pin stops.

Say if you wanted "two" firing pin strikes before the bullet leaves the bbl, could it be done with proof? thanks joe:)
 
jGee
I would bet money that double bounce can occur before the bullet leaves the muzzle !
Fred K
 
Fred K said:
jGee
I would bet money that double bounce can occur before the bullet leaves the muzzle !
Fred K
Click to expand...

Mr. Fred i aint saying it don't bounce -i'm sure anything is possible. How many times does it bounce before the bullet leaves the barrel. Can it bounce 4 or 5 times like a jack hammer before the bullet leaves the barrel? Is the number just 1 bounce? How does one prove how much it affects accuracy and how many times does it bounce?

I'm never going to be at the top of the list at any Rimfire meet, so what i think or say ain't gonna ever matter. I'm just sittin here at my computer looking out the window and was thinking "fireing pin bounce" - How does one know.

At one time people would bet the earth is flat, lol. I'll move on to something else, didn't mean to ruffle any feathers, thanks joe:)
 
jGEE said:
Mr. Fred i aint saying it don't bounce -i'm sure anything is possible. How many times does it bounce before the bullet leaves the barrel. Can it bounce 4 or 5 times like a jack hammer before the bullet leaves the barrel? Is the number just 1 bounce? How does one prove how much it affects accuracy and how many times does it bounce?

I'm never going to be at the top of the list at any Rimfire meet, so what i think or say ain't gonna ever matter. I'm just sittin here at my computer looking out the window and was thinking "fireing pin bounce" - How does one know.

At one time people would bet the earth is flat, lol. I'll move on to something else, didn't mean to ruffle any feathers, thanks joe:)
Click to expand...


Attach an oscilliscope wired accelerometer sensor to the aft end of the firing pin assembly and count how many times the sensor motion reverses itself in 2 milliseconds.................I am 99 percent sure that pin-bounce re-impact does not take place thru the slow mechanical movement of the firing pin/spring assembly in the short 2 millisecond time of cartridge ignition and bullet travel up and out the bore, unless for some unforseen circumstance.

I think Stuart Otteson in "Benchrest Actions and Triggers" calculated firing pin travel time from full cock to impact at appx. 3 milliseconds for a Rem. 700 centerfire pin with a 23 lb spring. Using that as a ballpark figure, you can see that a second rebound strike would take anywhere from a conservative 7-9 milliseconds, assuming the re-cock was not any slower than the forward motion which it is probably not, regardless, none of this comes in less than 2 milliseconds.............Don
 
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