What is the Firing pin tip protrusion on a Remington 700 bolt?
Firing pin ?
- Thread starter PestShooter
- Start date
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37 thou.
CatShooter
~55 thou
CatShooter
dmoran said:
???
If the pin protrudes 0.055", and the primer is 0.000" to 0.005" below the surface, then the penetration,kinda sexy ?) would be 0.050" to 0.055", if it was 0.020, then there would have to be ~0.035 of working headspace - and that,as Martha Stewart would say) "is a very badd thing".
I had a CCI BR-2 not fire a few weeks ago, and the dent in the unfired primer is large enough for a family if sparrows to build a nest in.
.
BoydAllen
Gold $$ Contributor
Actually, when firing a live round, the primer stops the forward motion of the firing pin, not the shoulder in front of the firing pin spring. This is why discussions of excess protrusion causing primer piercing are off base. All excess protrusion does is lessen effective firing pin fall, and slightly reduce the energy imparted to the primer. As an aside, firing pin protrusion is adjustable on Savages like the 110 etc., and Bob Greenleaf, retired Savage engineer, usually sets them at .035.
CatShooter
dmoran said:
Donovan...
Boyd gets no cigar.
Do what I described and you will see that Boyds explanation is not true.
He is entitled to his opinion, but when you test it, it is not true.
.
Unfortunately or fortunately as the case my be, I agree with Boyd. You, Me, or anyone else will never ever impact a primer deeper than .020-.025" short of using a center punch and a big hammer. Generally they run between .018"-.022"....measured.
Assuming zero cartridge head clearance, the primer seated flush with the casehead and a protrusion set at .050", the pin fall is shortened by .025" using the maximum impact depth, the amount equal to the protrusion less the impact depth. If the total pin fall length is .250", it only would be .225". Once you get at or below .200", primer ignition become unreliable. Increasing the protrusion further limits the overall travel and resultant impact pressures. Any drag or restriction to the pin fall also limits the impact pressures.
My pins are set to .035"-.040" and reliably ignite any primer, ever those dastardly hard and thick CCIs', or at least a few thousand anyway.
That "theory" can be demonstrated using a Savage action, the firing pin protrusion is easily adjusted. Set the protrusion to .060" then to .035" and measure the impact depth differences using various makes of primers. BTW, also check and /or reset the cocking piece pin stop position when the protrusion is changed.
Bill
Assuming zero cartridge head clearance, the primer seated flush with the casehead and a protrusion set at .050", the pin fall is shortened by .025" using the maximum impact depth, the amount equal to the protrusion less the impact depth. If the total pin fall length is .250", it only would be .225". Once you get at or below .200", primer ignition become unreliable. Increasing the protrusion further limits the overall travel and resultant impact pressures. Any drag or restriction to the pin fall also limits the impact pressures.
My pins are set to .035"-.040" and reliably ignite any primer, ever those dastardly hard and thick CCIs', or at least a few thousand anyway.
That "theory" can be demonstrated using a Savage action, the firing pin protrusion is easily adjusted. Set the protrusion to .060" then to .035" and measure the impact depth differences using various makes of primers. BTW, also check and /or reset the cocking piece pin stop position when the protrusion is changed.
Bill
You guys are all kinda rite....I just happen to be shootin here in the front yard today!!!!hahaha....I am a luky guy...I have a 200yd range rite at my front door...and 500 if I go to the bak of the farm....pretty handy....
Welll any way...I measured a cupla fired roudns and the pin made an impression in the primer...,I measured it with a depth guage on the primer and by fireing pin fall in the bolt shoroud)...a fired round,6mmBR Fed-205) was around .018-020" ....if I ignited a primer with no powder charge-no bullet the dent was around .040"...it seems that the pressure of ignition.,chanber pressure) pushes the primer cup and the fireing pin/fire control to the rear a lil'---I know when I am flirting with poppin a primer somtimes there is very little to none of and indentation in the primer cup when I pull out the fired round....
Soooo to me...IMHO...the fireing pin can not dent the primer the full .055",which is what my Panda action measured here this afternoon) because of having to coin or stretch the metal cup...even on one with "no" pressure...thn when the pressure is up to normal,or above) the dent seems,measures less) shawoler because of the paramaters of the round..!!!! hope this makes sense and evrybody can shake hands and get to shootin and not-a-putin on the puter.....hahahah......Roger
Welll any way...I measured a cupla fired roudns and the pin made an impression in the primer...,I measured it with a depth guage on the primer and by fireing pin fall in the bolt shoroud)...a fired round,6mmBR Fed-205) was around .018-020" ....if I ignited a primer with no powder charge-no bullet the dent was around .040"...it seems that the pressure of ignition.,chanber pressure) pushes the primer cup and the fireing pin/fire control to the rear a lil'---I know when I am flirting with poppin a primer somtimes there is very little to none of and indentation in the primer cup when I pull out the fired round....
Soooo to me...IMHO...the fireing pin can not dent the primer the full .055",which is what my Panda action measured here this afternoon) because of having to coin or stretch the metal cup...even on one with "no" pressure...thn when the pressure is up to normal,or above) the dent seems,measures less) shawoler because of the paramaters of the round..!!!! hope this makes sense and evrybody can shake hands and get to shootin and not-a-putin on the puter.....hahahah......Roger
FroggyOne2 said:
just so that you know.. I got that number from David Tubb and we talking about Remington bolts.
Boyd is correct
-AlAnd the firing pin only needs about 170 thou of fall to ignite that primer too.. but no less than 170 thou.
Firing pin pressure of 8000 psi???? Better check your calculator batteries. Impact energy is more in the neighborhood of about 4 in lbs.
CatShooter, you sound like a reasonably intelligent guy and I'm not going to engage in a debate about math and numbers. I realize I'm not good in calculus and where I lack, I'm smart enough to seek the help of people who are. I've been researching this "ignition" situation for over 5 years, and have developed my own formula that works, with the help of people in this industry that know their stuff. I would suggest before being smug and "matter of fact" about the situation, you talk with the same people I did, John Pierce, Jerry Stiller, Bruce Thom, Bob Greenleaf and George Kelbly. These guys know more about what works and what don't than anybody at Remington.
What happens on paper and what happens in reality may not be the same. By the way, have you ever actually checked a spring on a spring scale?
What happens on paper and what happens in reality may not be the same. By the way, have you ever actually checked a spring on a spring scale?
AlNyhus
Silver $$ Contributor
catshooter:
If you go back and re-read my post, you'll not see anything that says "you can't" set the pin assy. up to have the shoulder stop the foward motion of the pin...only that there are reasons that you don't want this to be the case.
There's quite a bit of difference in the static setup of the ignition system versus how it functions in the dynamic state. The primer itself is a much bigger, albeit underestimated, part of the dynamics of ignition than most realize. That reliable ignition occurs over approximately 50% of the total firing pin protrussion range,.030 as a safe minimum with .060 total protrussion) is just one indicator of this.
Jim Borden is one of the nations best when it comes to ignition systems. His formal training as an engineer, his work on sorting out problems with other peoples setups and his application of these proven facts to his own line of actions is highly regarded in the shooting industry..especially among serious competitors who leave no stone unturned and investigate every area for possible gains.
Stan Ware recently finished a complete ignition system/bolt timing rework for me on a custom action that had been plagued by inconsistent ignition and bolt timing issues since it was new. What I learned as we worked through that project has given me some new perspective on how a seemingly straightfoward thing like the ignition system is actually very complex and subtle in how it actually works.
Applying critical thinking skills, along with reading comprehension, is never a bad thing.
Respectfully -Al
If you go back and re-read my post, you'll not see anything that says "you can't" set the pin assy. up to have the shoulder stop the foward motion of the pin...only that there are reasons that you don't want this to be the case.
There's quite a bit of difference in the static setup of the ignition system versus how it functions in the dynamic state. The primer itself is a much bigger, albeit underestimated, part of the dynamics of ignition than most realize. That reliable ignition occurs over approximately 50% of the total firing pin protrussion range,.030 as a safe minimum with .060 total protrussion) is just one indicator of this.
Jim Borden is one of the nations best when it comes to ignition systems. His formal training as an engineer, his work on sorting out problems with other peoples setups and his application of these proven facts to his own line of actions is highly regarded in the shooting industry..especially among serious competitors who leave no stone unturned and investigate every area for possible gains.
Stan Ware recently finished a complete ignition system/bolt timing rework for me on a custom action that had been plagued by inconsistent ignition and bolt timing issues since it was new. What I learned as we worked through that project has given me some new perspective on how a seemingly straightfoward thing like the ignition system is actually very complex and subtle in how it actually works.
Applying critical thinking skills, along with reading comprehension, is never a bad thing.
Respectfully -Al
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