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Firing Pin Replacement

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  • Firing Pin Replacement

    What is the spec. length of the M-! firing pin? I had several failures to fire at the range yesterday after running through 42 rounds. There was no marks on the primers. Fired cases showed a good crater.My rifle is a Springfield s/n 19194XX that I got from DCM in the early 80's & have been shooting with the original parts ever since. The pin measures 3.772, & I'm replacing it with my spare that is 3.776 It'll be a while before I can get back to the range to see if this is my only problem. Thanks for your help.
    Last edited by seadog; 03-25-2018, 02:38 PM.

  • #2
    First what ammo are you shooting? Does not sound like a firing pin problem but a problem with the bolt not rotating fully closed. If the bolt does not fully rotate closed the safety bridge prevents the firing pin from moving forward. Clean your chamber with a chamber brush. Check the over all length of your ammo to make sure its in spec. Welcome to the forum.


    • #3
      Thanks for your input. Shooting my reloads: LC-67 brass,f/l resized 5x, 165gr.fmj/bt, wwlr primer, 46.5gr H4895, oal 3.295-3.300. I'll check bolt lock-up next trip to range.BTW, I had been a forum member some time ago, but couldn't get back in with my old user name:"oldshot" so I re-registered. What do I have to do to d/c oldshot?


      • #4
        I agree it is not a firing pin issue . When the rifle FTF have you noticed is the bolt all the way into battery?


        • #5
          To be honest, I don't remember. I was firing single rounds using a SLED & had gone through about 40+ with no problems,when the first FTF occurred. I racked the bolt back, ejected it and tried 2 more times (3 rds. total) with same result. The primers were without any evidence of a hit.The shoulders seemed OK:No scratches or dents, so I believe they chambered OK.I have since dissembled the gun. Trigger group is OK: No broken springs, or damaged hammer/other parts. Took bolt apart same deal, that's why I asked about the Mil-Spec on the fp.


          • #6
            If you had no marks on the primers the bolt wasn't all the way to battery unless the firing pin is broken. With a floating pin if the hammer contacted the firing pin it would have fired or left a mark. Obviously the bolt never closed far enough to even snap the extractor over the rim since every round loaded in a Garand with full bolt closure will result in a shallow pin mark on the primer whether you drop the hammer or not. The Garand has a safety feature built in that prevents out of battery fire by preventing the hammer from contacting the pin when even very slightly out of battery.

            One thing that will definitely prevent full closure is improper lubrication with GREASE on the bolt lugs and lockup areas of the receiver. It's pretty coincidental that it started malfunctioning after about 40 rounds since that's generally about how many rounds it takes for an improperly lubricated rifle to develop that malfunction. You may also have carbon contamination or brass contamination in the chamber. Are the cases scratched when you eject the unfired rounds or is there and denting on the shoulders? It doesn't take much in the way to prevent full closure to battery. Quite often, polishing the chamber with Kroil and fine steel wool that fits the chamber tight in a patch holder turned by cleaning rod driven by a drill at the muzzle. Or use a tight patch and Bore Paste turned by the same method. Either one will buff the chamber without harm.


            • #7
              First, many thanks to all for your concern and excellent advise. The chamber was "clean" as a solvent soaked patch on my combo tool came out gray after the first few wiggles and a fresh patch was much lighter. Brass ejected was unremarkable. I put the DNF rounds through again and they still refused to fire. The primer pocket's chamfer to remove the crimp ( LC cases) looked a little too bright for their age, so I placed a straight edge across the base and under a magnifier the primers were very low vs some of my newer re-loads.I pulled the bullets,salvaged them
              and the powder and tossed the brass. Hopefully problem solved. No problem firing the newer re-loads. Again, thanks to all.