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Thread: FN49 Firing Pin

  1. #1
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    Default FN49 Firing Pin

    I just received my new two piece firing pins and springs for my FN49's. I installed them and realized the full length firing pin can be cut to 69.00MM and the front firing pin with a new spring can be added instead of purchasing the rear section of the two piece firing pin. I'm sure I can machine it down to 69.00MM. In my 3 FN49's I did also notice each used/orginal firing pin spring was shorter than the new ones. No two were the same length. One fn49 had a different firing pin spring too it had a thicker wire but it was shorter too like the rest. So if your going to still use the one piece firing pin I would suggest getting a new spring for it. This could be why the slamfires are occuring because of a weak firing pin spring. Well one reason anyhoo.

    Being an engineering lead tech (retired) its just in me to still find out why things fail before i replace them. We need to know why it broke before we actually repair the problem, we need the root cause first.
    Are you ready for 12-21-2012?? Lets pray its the second comming of Christ and not the end like so many predict.

  2. #2

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    where did you get the two peice fireing pins from thought they were all sold out. thanks for any input

  3. #3
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    Numrich Gun Parts they came here lastweek.
    Are you ready for 12-21-2012?? Lets pray its the second comming of Christ and not the end like so many predict.

  4. #4
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    Default FN 49

    Does anyone have an idea of where a two piece 7mm Veni fireing pin, with the bolt stop could be obtained? I ordered one from Gun Parts and was sent one from an Egiption.SP

    Thanks,
    Bill

  5. #5
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    Quote Originally Posted by seabee View Post
    Does anyone have an idea of where a two piece 7mm Veni fireing pin, with the bolt stop could be obtained? I ordered one from Gun Parts and was sent one from an Egiption.SP

    Thanks,
    Bill
    I believe the two piece firing pins with the springs are the same and interchange with each FN49. My egyptian 8mm, my LUX 30-06 and my Vene 7mm all apear to be the same lengths. I think the springs had changed lengths do to wear and the age of them, the orginal springs were much shorter when i compared them to the new springs. I did check the firing pin protrusion too and it seemed ok with each bolt after the two piece firing pins were installed. These parts were not marked as to which country they were for too. The package only said FN49 or the part number. I don't have any knowledge of the bolt stops.

    Some of these new rear firing pin sections may need to be fitted too. I had one that was tighter than the rest of the ones i had. The first thing is to check it for maching burrs and then stone it and polish it with steel wool till it fits freely in the firing pin bore of the bolt body. The two piece firing along with any firing pin needs to float freely so it won't stick and slamfire.

    I did notice the one piece firing pin can be cut to 69.00MM from the rear(your removing the orginal firing pin and making the length of the rear section at 69.00MM. This way you only need the new front firing pin and the new spring. You can save some $$ if you can cut it at the correct length and face it off.

    I haven't done much with my FN49's but there starting to grow on me now.

    Maybe Goose52 will chime in and clear it up too.
    Last edited by 1911crazy; 09-12-2009 at 12:24 PM.
    Are you ready for 12-21-2012?? Lets pray its the second comming of Christ and not the end like so many predict.

  6. #6
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    Quote Originally Posted by 1911crazy View Post
    ...and realized the full length firing pin can be cut to 69.00MM and the front firing pin with a new spring can be added instead of purchasing the rear section of the two piece firing pin. I'm sure I can machine it down to 69.00MM.
    Other people have reported cutting down the one-piece firing pin to create a rear section of the two-piece design. None have reported any long-term results as to whether they ended up with any peening on the cut portion of the pin. In addition to any potential peening issue, dimensional accuracy and checking for firing pin protrusion would be critical if one chose to modify the original FN parts.

    Quote Originally Posted by 1911crazy View Post
    Being an engineering lead tech (retired) its just in me to still find out why things fail before i replace them. We need to know why it broke before we actually repair the problem, we need the root cause first.
    FN had two basic versions of the one-piece firing pin - a long nose and short nose. The short-nose pin may have been an effort to reduce bending at the nose. There were two basic configurations of the rear section of the two-piece firing pin - the later version eliminated one of the right-angles in the retention notch and replaced it with a radiused or ramped profile - probably made to reduce the likelihood of crack propagation at this point. Given the number of changes made to this part, it would appear that FN was trying to identify and eliminate failure root causes as well !

    Quote Originally Posted by seabee View Post
    Does anyone have an idea of where a two piece 7mm Veni fireing pin, with the bolt stop could be obtained? I ordered one from Gun Parts and was sent one from an Egiption.SP
    Thanks,
    Bill
    All of the one- and two-piece firing pins are essentially interchangeable ... although it's becoming clear that checking for firing pin protrusion is critical. In the case of a Venezuelan contract rifle, you are looking not only for a two piece firing pin - but ALSO a rear section that is slotted for a firing pin safety stop. See photo of a slotted rear section. Numrich has both sections of the two-piece pin, but most people report that they are OUT of slotted rear sections that you would need for proper operation of the FPSS.


    When you say that you also want a bolt stop - do you really mean you need an FPSS? If you are missing the FPSS for your Venezuelan - then you're just about out of luck. The FPSS for this contract was unique - not used on any other contract - and spares for this part are just not available. If you really just need a bolt stop - these are common across the contracts - shop at these sources:
    http://www.sarcoinc.com/fn49.html
    http://www.e-gunparts.com/productsch...odel=1410z1949
    http://www.ssporters.com/FN49.htm
    https://www.apexgunparts.com/

    Goose
    Read a good book lately?
    www.fn49.com

  7. #7

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    Don't know if anybody else does this...
    I get an empty case and fill the primer hole with a fairly hard clay.

    Then I remove the magazine and the extractor. I manually load the
    case and let the bolt slam forward.

    I always like to test new springs in this way, just to be safe.
    Never had any indentation with original fn springs.

    Maybe not an exact science, but I feel more reassured this way.

  8. #8
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    Quote Originally Posted by abl View Post
    Don't know if anybody else does this...
    I get an empty case and fill the primer hole with a fairly hard clay.

    Then I remove the magazine and the extractor. I manually load the
    case and let the bolt slam forward.

    I always like to test new springs in this way, just to be safe.
    Never had any indentation with original fn springs.

    Maybe not an exact science, but I feel more reassured this way.
    Hmmm, that's an interesting idea. What kind of "clay" do you use to do this?

  9. #9
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    Thanks Goose52 for chiming in. As far as I could tell the 3 firing pins all looked the same. Like I said the only difference i noticed between the one piece firing pin and the two piece firing pin was the length of the springs of course the older ones would be shorter.

    All three of my new rear firing pin sections have the slot in them too. Maybe i got lucky.

    The way the rear section of the firing pin looks they cut it at the smaller diameter to make it exactly 69.00MM. This would leave me to believe the hardness is right thru that smaller cross section too. I would beaware of this when cutting the one piece firing pin to shorten it for the new rear section. I would go slow with a cut off wheel and cool it with water while cutting it or inbetween cutting it so your not changing the hardness of the rear section. I would also suggest putting a tad of grease between the two piece firing pins too. This would soften there inter action to prevent peining too. Just one spot of grease on the mating parts. Leave the spring dry.

    Now believing the one piece firing pins lasted for so many years it would lead me to believe the firing pin spring is the problem with slam fires as it goes weaker over time, its still in a compressed state. Springs do fail or lose there tention over long periods of time. I would suggest with any older military semi-auto rifle that has a firing pin spring it should be checked against a new one for the difference in length or just replaced for safety. Whats a few $$ for a new spring. Its not worth the risks of having an accident.
    Are you ready for 12-21-2012?? Lets pray its the second comming of Christ and not the end like so many predict.

  10. #10
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    Quote Originally Posted by 1911crazy View Post
    Now believing the one piece firing pins lasted for so many years it would lead me to believe the firing pin spring is the problem with slam fires...
    Certainly a weak firing pin spring could be a contributing factor ... but the one-piece firing pins haven't really "lasted for so many years." The one-piece pin started breaking and causing slam-fires soon after the rifle entered in service in 1949. By around 1952 or so, the two-piece firing pin design was released and used on all subsequent rifle deliveries. It appears that none of the using nations having pre-1952 deliveries conducted a recall/replacement effort and only replaced the pins as they broke. So, the early contracts like the Venezuelan, Egyptian, first Luxembourg order, etc. are often found with the one-piece pin. Later contracts, like the Argentine, are usually always found with the two-piece pin.

    Breakage of the one-piece pin is real - I've had it happen to one of my rifles already and now routinely install a two-piece firing pin in every FN-49 that I acquire.

    Goose
    Read a good book lately?
    www.fn49.com

  11. #11
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    My Fn49 Vene & my FN49 Egyptian both still had one piece firing pins still intact. On my FN49 Lux it had the two piece already in it but the spring was much shorter than the springs.
    Are you ready for 12-21-2012?? Lets pray its the second comming of Christ and not the end like so many predict.

  12. #12

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    Quote Originally Posted by texaggie77 View Post
    Hmmm, that's an interesting idea. What kind of "clay" do you use to do this?
    Normal pottery clay.
    Just make sure it's not too soft so it will drop out.

  13. #13
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    UH-OH!!!

    The Veni and I went to the range this Morning and burned some powder together...

    Aaahhh... the pungent aroma of burnt nitrocellulose on a crisp Autumn Morning!

    Upon getting back and pulling it down for cleaning, I took a notion to pop the FP and take a look see at it, having read all this stuff about one-piece vs. two-piece for all these years.

    I got the rim of a 7.62 X 54R casing that happened to be lying around on the bench under the tang of the little retainer clip, got a thumb nail under the top of it, pried it up and pushed it downwards, rotating 90* to release the FP. Then pulling it straight out, "*POP*" went the FP briskly to the rear, propelled by what certainly seems like a good strong spring.

    One look at my FP and I went "UH-OH!!!";

    ............

    So I guess I'd better hope someone has a Veni slotted 2-piece FP, huh?

    Other than the slot, are the other specs the same? Could a non-slotted FP have the temper drawn, the slot milled, and then re-hardened? I would hate to run it without the FPSS.

  14. #14
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    Question Update; 2-pc. FP

    I ordered the 2-piece FP from GPC and e mailed them requesting a slotted one if they had it.
    Much to my delight, they replied in the affirmative.
    The pin set arrived today and both appear to be unused -

    .....

    I wonder if these are original FN parts or reproductions?

    I thought that these locked together like the Springfield FP does, but the ends are just solid square cut-offs with a very short sub diameter "stub" in the center.

    ..............

    Whats the scoop with these things? Do I just slip the spring over the nose of the forward section and drop it down the FP channel, followed by the rear section so that they just butt together?

    It would seem that if I had excessive FP protrusion that I could take a little steel off of one of those "stubs" on the abutting ends to bring it down, rather than mess with the tip of the pin.

    I'll give it a try and see what happens.

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