1. Attention: We have put together a thread with tips and a tutorial video to help with using the new software. Please take a moment to check out the thread here: Trapshooters.com Tutorial & Help Video.
    Dismiss Notice

Question on firng pin protrusion....

Discussion in 'Shooting Related Threads' started by mikepacific60, Mar 22, 2012.

Thread Status:
Not open for further replies.
  1. mikepacific60

    mikepacific60 Member

    Joined:
    Jan 29, 1998
    Messages:
    86
    Question on firing pin protrusion….

    My Perazzi (and a friend of mine – Smiley -) have an issue with pierced primers on the bottom barrel of our Perazzi MX8’s (we both use factory cartridges only).

    This seems to happen with a particular type of hull used by manufactures here in Australian and New Zealand.

    My question is how far should the firing pin protrude from the breach face when the hammer is fully down (to test this in a leaf spring Perazzi you can hold the hammer forward against the back of the breach face and measure the protrusion with a calliper) – even easier in a coil spring Perazzi!

    I am tempted to slightly shorten the nose of the firing pin in an attempt to deal with this problem, but I don’t then want to wind up with too light a strike and risk misfires.

    Any info welcomed & regards from Australia, Mike
     
  2. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,408
    I have tried to measure firing pin protrusion in Brownings using the technique you describe (hammer against the back of the breach) and found it to be inaccurate because the firing pin travels further than just what sticks out of the breach face.

    To accurately measure protrusion in my Xts I have to remove the stock, cock the hammer and use a small wood dowel against the back end of the firing pin to push it completely forward in its bore and THEN measure the length that protrudes from the breach face. According to a smith at Browning, the "spec" is .050"-.070" full protrusion.

    Yes, it's a fiddle but the return spring on the firing pin pushes it back away from the breach face so shell bases don't hit it when the gun is closed. With the hammer down I may measure only about .032" of pin protruding from the breach face; by pushing the pins forward with the dowel I may find that they actually protrude as much as .075" after being struck by the hammer.

    If your coil spring Perrazis work the same way (and I've never seen the internals of one) you'll need to push the pin forward to get accurate measurements.

    Keller
     
  3. hmb

    hmb Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    9,442
    Instead of shortening the firing pin, how about replacing the firing pin return spring with a slightly longer spring. Or stretching the existing spring. HMB
     
  4. lostandout

    lostandout Member

    Joined:
    Jun 29, 2010
    Messages:
    450
    i shortend the firing pin on a winchester select energy as it was dooing the same thing ground the pin a buffed smooth just go about .005 at a time it will work you may have to do it a few times but it will not end up to short that way



    brian
     
  5. mikepacific60

    mikepacific60 Member

    Joined:
    Jan 29, 1998
    Messages:
    86
    Hi to all - thanks for the comments.
    HMB - I'm not being smart here, but I'm not sure that the return spring has a role in my problem (pierced primers).
    Brian - the approach you used sounds like the go - have you had any misfire problems (with other cartridge brands) since shortening the pin?
    I do wonder if there is a 'definite' protrusion measurement (for example, 40 thou)?? Cheers Mike
     
  6. miketmx

    miketmx Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    2,971
    I agree with Gary, buy different primers or shells. I also have the same experience as Keller with the hammer resting on the firing pin = meaningless. I have a leaf spring trigger for my TMX and also a coil spring trigger for it. When the coil spring trigger is in the gun and the hammer is resting on the firing pin it protrudes from breech face but when the leaf spring trigger is in the gun it (the hammer) does not even touch the firing pin unless you actually shoot it. My conclusion is that the momentum of the hammer falling will strike the firing pin the right amount but just resting the hammer on it means nothing. My primer indents are perfectly normal with either trigger in the gun.
     
  7. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,408
    <blockquote><I>"Instead of shortening the firing pin, how about replacing the firing pin return spring with a slightly longer spring. Or stretching the existing spring."</I></blockquote>The return spring has no hope of preventing the full travel of the firing pin no matter how much you stretch it.

    Keller
     
  8. Avaldes

    Avaldes Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    1,876
    Location:
    Central Coast of California
    Ok, one issue not mentioned is that the two piece firing pins can slip with excessive use. The inner part can move forward creating more protrusion when it hits the shell. You might change out your firing pins first to see if that helps. If not, then you can grind the first set down while they are out of the gun.

    There was a thread about pierced Rio primers here just the other day...
     
  9. Stl Flyn

    Stl Flyn Well-Known Member

    Joined:
    Apr 6, 2010
    Messages:
    8,747
    Had this happen with my KS-5 after it was serviced. The firing pin kept piercing the primers. Had to file it down just shy of a 1/16". Have not pierced a primer since, and have never had a misfire. If you file as stated above do it slowly, and test it, after each millimeter of removal. Also make sure that it stays rounded off. Jon
     
  10. 2llc

    2llc Well-Known Member

    Joined:
    Jun 8, 2011
    Messages:
    1,099
    Location:
    Eastern Oregon
    The normal firing pin protrusion (maximum)is .055" for a rifle. I suspect that would work fine for shotgun also but surely there is a shotgun smith somewhere that can reveal the correct dimension without guesswork. Larry
     
  11. 2llc

    2llc Well-Known Member

    Joined:
    Jun 8, 2011
    Messages:
    1,099
    Location:
    Eastern Oregon
    A quick look on the Brownells web site under firing pin protrusion indicates that Shotguns run a bit longer that rifle..... .055" to .065" of an inch. Perhaps Perazzi has a contact that could provide you with the correct number..Larry
     
  12. BL350

    BL350 TS Member

    Joined:
    Jan 29, 1998
    Messages:
    244
    Dear MP60,
    SAAMI has a standard for the actual foring pin protrusuion dimension. NOTE! Not all firing mechanisms suit this spec. Some shotguns use an inertia system I.E. Rem. 100/1187. DIFFERENT CRITTER!
    IN YOUR Perazzi MX-8 with the rebound hammer (using a pull trigger).045 inches works well for me.(measured protrusion with hammer forced against the rear of the breach block.
    .....I would remove the pin and spin it in a lathe or drill chuck and just polish the point to a nice radius. NO PITS OE ROUGHNESS SHOULD BE VISIBLE. Do not shorten the pin!!! I have seen many pierced primers with black residue in the indentation. Usaually are Cheddites or low cost primers using a steel face. High quality tatget ammo has brass...actual brass face in the primer! Such as Rem STS, Win Premium. and others. I wouldn't get concerned about pierced primers occurring 2 or 3 per 100...except the expelling gases will erode the end of the pin. and...Please wear safety glasses while shooting also!! Shortening a Perazzi factory pin is not necessary. Failures to fire are very upsetting to most shooters and shortening a pin will increase your FTF condition. Polish the pin and shoot more!....Respectfully submitted...X-Jet Boat Bill
     
  13. Smokechaser

    Smokechaser TS Member

    Joined:
    Dec 19, 2011
    Messages:
    94
    Be careful working in this area. Any removal of metal from the forward point of the firing pin can effect the annealed steel and turn that hardened pin into a soft point that will cause problems as it starts to mushroom down the road. If you need to remove some mental, do it on the hammer end, not the striking end...

    Also, buy a few spares and check them. Replace the springs and bring the gun back to factory standards. Springs work both ways, and do affect the performance both ways. If the firing pin channel is cleaned and without nicks, and a new firing pin and spring are installed and the problem still continues, a trip to the factory seems the best approach. The breech face may come into the equation then. If it only happens to certain brands of ammunition and not with others, the simple answer would be to change to a brand that doesn't exhibit the problem...

    Hope things work out well, but put down the files and metal paper until the problem can be zeroed in on the reason....cya
     
  14. TOOLMAKER 251

    TOOLMAKER 251 Active Member

    Joined:
    Jan 29, 1998
    Messages:
    3,398
    If you want to shorten a firing pin, remove metal from rear and not from the tip.
     
  15. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,408
    <blockquote><I>"High quality tatget ammo has brass...actual brass face in the primer! Such as Rem STS, Win Premium. and others."</I></blockquote>The primer cups from the four primers that I use (L to R)... CCI, Remington STS factory, Federal Gold Medal factory, Winchester.

    Of the 4, only the Winchester on the far right has a brass (or at least a non-ferrous) primer cup; the other three are steel according to my magnet:<center>
    [​IMG]<br>Photo is only to verify that primer cups were removed from the primers and emptied<br>before being magnet tested.</center>

    Keller
     
  16. BL350

    BL350 TS Member

    Joined:
    Jan 29, 1998
    Messages:
    244
    Dear UK 1,....I performed my primer cup material test about one year ago and still carry the samples in my shooting gear for demo with a magnet. I will dis-assemble some more this weekend and repeat the test and submit a photo......Sincerely, X-Jet Boat Bill
     
  17. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,408
    BL350...

    Do whatever makes you happy... I'm satisfied with my results.

    Keller
     
  18. BL350

    BL350 TS Member

    Joined:
    Jan 29, 1998
    Messages:
    244
    Dear Unknown One, I marked known primer samples today. Red for WINCHESTER and GREEN for STS Primer samples. I then disassembled the cups. The poor quality picture attached shows the primer faces about 1/4 inch from a magnet. All of these samples are non-magnetic and are brass. The Winchester sample is current production and two of the Remington samples are current production. The last two green ones were extracted from Grand American Cases dating back to 1996.......Sincerely, X-Jet boat Bill
    bl350_2008_030312.jpg
     
  19. Barry C. Roach

    Barry C. Roach Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    9,209
    Location:
    Scottsdale, AZ
    Unless the firing pin is separatiing (two piece pins only) the problem is not the gun. IT"S CRAPPY PRIMERS. If it's only one kind of primer or shell that's causing the problem I'd look there first. I'd replace the pin anyway since I do once a year anyway.
     
  20. mikepacific60

    mikepacific60 Member

    Joined:
    Jan 29, 1998
    Messages:
    86
    Thanks everyone for the comments. With respect to the condescending remarks of Mr Waalkes, I have some experience of Perazzi shotguns and would not do anything to put the gun at risk. Perazzi firing pins sometimes do need to be fitted to the individual gun – I have seen new pins that are too long and protrude from the breach face when the gun is uncocked (unsafe).
    I do not think it inappropriate to ask such a question on this trapshooting discussion site & wonder why Mr Waalkes thinks that derogatory comments are called for. Regards to all, even Mr Waalkes, Mike.
     
Thread Status:
Not open for further replies.
Search tags for this page
best length pistol firing pin protrusion
,
firing pin protrusion shotgun
,
how far should firing pin protrude
,
how far should firing pin protrude on a shotgun
,
how to shorten a firing pin
,

shotgun firing pin protrusion

,
sxs firing pin protrusion
,
winchester select over under firing pins