FN49 owners -- question on slam fire and firing pin


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iamkris
September 15, 2007, 11:07 PM
I have a really good looking Egyptian FN49...took it out shooting for the first time today with some boxer primed Hirtenberg 8mm.

http://www.thehighroad.org/attachment.php?attachmentid=55049&d=1174236550

I was only firing single shot...e.g., only putting 1 round in the magazine at a time. I did not try to load the magazine to full capacity. When letting the bolt fly home to strip the catridge and load the chamber, I experienced a slam fire on two occasions. For all the other times I loaded it, I slowly ran the bolt carrier forward.

I've field stripped the action...there is no cosmoline jamming the firing pin. It is not otherwise stuck a forward position. The pin does seem to have quite a bit of free travel with what feels like a return spring at the end of its travel.

Questions:

Is the firing pin supposed to be free floating or spring loaded?
Is slam firing a common occurence with these rifles?
The Hirt ammo is mil surplus so I'd think it capable of withstanding a light blow...anyone else had this issue?


The rifle appears to be wonderfully accurate by the way...4 shots touching at 50 yards. Thanks in advance for the advice.

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trueblue1776
September 15, 2007, 11:16 PM
You may have a worn pin spring.

Onmilo
September 16, 2007, 01:14 AM
This is an expected experience with this rifle and others similar such as the M1 Garand, the M1 Carbine, and the M1A/M14.

You cannot drop a cartridge in the chamber at just let the bolt fly home because inertial will allow the firing pin to move forward with sufficient force to fire the cartridge before the bolt is in full battery.

There is no firing pin spring on these weapons.
When used as the designer intended there is no need for one, a one less part bonus in a military use weapon.
Like the M1 Garand they rely on a mechanical piece to keep the firing pin to the rear until the bolt is in full battery.
In the FN-49 this piece is called a Firing pin stop.
Like the M1 Garand/M14 firing pin bridge this piece keeps the bolt to the rear until the bolt is in full battery.

If you load cartridges by dropping them into the chamber and then let the bolt fly home, this firing pin stop piece will be overwhelmed by the additional bolt velocity caused when there is little or no friction from the action of stripping a cartridge out of the magazine to slow its progress.

One should never drop cartridges into the chamber and then let the bolt fly home on any of these rifles, always feed cartridges to the chamber from the magazine.
As you found out, it is a surefire, pun intended, way to induce a slamfire.

Trebor
September 16, 2007, 02:43 AM
I agree. By bypassing the magazine the bolt no longer was slowed down by stripping a round from the mag. That extra "omph" on the bolt is enough to increase the odds of a slam fire.

Slam fires are a known danger on the 8mm FN 49's due to the lack of a firing pin spring and the one-piece firing pin. Often when a slam fire occurs the weapon will often fire out of battery as well.

My advice is to stop loading by dropping a round directly into the chamber. You may also want to hunt down an aftermarket two-piece firing pin. I know a couple different people have offered those over the last few years. They were designed to eliminate the possibility of slam fires. Unfortunately I don't have any contact info or other info to help you find one.

Ask over at www.falfiles.com and someone there might be able to track down a two piece firing pin for you.

iamkris
September 16, 2007, 08:49 AM
You cannot drop a cartridge in the chamber at just let the bolt fly home because inertial will allow the firing pin to move forward with sufficient force to fire the cartridge before the bolt is in full battery.


My advice is to stop loading by dropping a round directly into the chamber.

Sorry guys...apparently I wasn't clear in my description. When I said I didn't load the magazine, I meant I didn't load it with multiple rounds. I DID however put the single round in the mag and let the bolt fly home. (I'm going to edit the OP to make that clear)

Since the bolt was stripping the round out of the magazine but still slam firing, it makes me think that this behavior will happen whether I put, 1 round, 2 rounds or a full mag in.

Now that I made that clear, what do you guys think? The advice to get a 2-piece firing pin is a good one, however, this rifle seems to be slam firing during normal operation.

Trebor
September 17, 2007, 05:56 AM
The 2 piece firing pin should eliminate the slam fire problem. The FN 49's are known for a tendency to slam fire and that's why someone made the 2 piece FP's.

Onmilo
September 17, 2007, 09:32 AM
Two piece firing pin should help.

FN-49s like FN-FALs can fire out of bettery if the one piece firing pin breaks.
They aren't really noted for slam firing any more than any other semi auto rifle.

I also think I may be wrong and the FN-49 rifles do have a firing pin spring.
Replacing this may also help.

iamkris
September 17, 2007, 09:42 AM
Thanks...I think I'll start with the firing pin spring ($3) and work my way up to replacing the firing pin itself ($40)

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