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Acrobat
June 19, 2002, 07:52
Yesterday I fired the G1 I just finished building from a Tapco parts kit and have a problem with the trigger action. The firing pin is not remaining cocked after the action cycles.

I started out by single loading the rifle fith the gas setting fully opened and adjusted one click at a time until the bolt would hold open (this occured at a setting of four). Then I started loading two rounds in the mag and began noting that while the second round chambered fine, the rifle was not remaining cocked. When I extracted and examined the unfired round, I noticed a light indentation on the primer, indicating a weak pre-mature release of the firing pin (fortunately, the primer dent was too light to cause a discharge on the second round). I removed the mag so the bolt doesn't stay open and single loaded again. In each case, the results were the same with the firing pin released instead of remaining cocked.

I cannot replicate this by manually operating the bolt. It only occurs when firing a live round.

My HTS is the cheap stuff from Century (I bought the same US parts kit that I'd previously used with good success in my Imbel build six months before). The trigger feel is good with no appreciable creep. I guess I can start swapping parts between the two FAL's but before I did that I thought I'd write and see if I could understand which part in the trigger group is most likely causing the firing pin to release and if there are cures other than replacing HTS.

kurt

stimpsonjcat
June 19, 2002, 12:48
I assume you mean the hammer is not remaining/being set after firing a round? The firing pin is simply floating with a spring holding it to the rear...it is normal for there to be a light primer strike when the bolt/carrier loads a live round and then you eject it without firing it. Of course, if the spring is too worn, this could get dangerous (slam fire).

If the hammer doesn't get reset when firing, but does when mnually working the bolt. Then either the bolt isn't going rearward enough to lock the hammer or the HTS parts are failing to hold on sear. If the ejection is nice and brisk, we can rule out the bolt not moving far enough rearward.

If it is the HTS...I'd recommend replacement over tinkering with them. Do a search for FSE here and you can order some of their parts. A basic test to check HTS is to CLEAR THE WEAPON, then rack the bolt and pull the trigger, now keep the trigger pulled and rack and release the bolt again. The hammer should remain back (you can leave the dust cover off while performing this test to see what is going on). Now veeeerrrrry slowwwwwly release the trigger, if the hammer falls rather than catching on the sear you have a bad part. Be sure to run the test several times.

be forewarned that this failure is sometimes only manifest when actually firing as the violence of the cycling process causes a partially bad part to fail to function.

If you get new parts, get a new sear spring while you're at it.

orca
June 19, 2002, 13:52
it really sounds as though you are selected to full auto on your safety......it does happen quite often, orca

mountain man
June 19, 2002, 16:52
Yeah, my G1 will do exactly that if you push the selector too far.

Eightball
June 19, 2002, 18:55
same here with my stg.......
make sure you dont have selector in full auto.

Acrobat
June 19, 2002, 22:12
Thanks everyone for the ideas.

stimpsonjcat really nailed the problem. Once I separated the upper from the lower I could see that if I released the hammer and continued to hold the trigger back, the hammer would not reset.

I took the HTS apart again and compared them to the originals. With the help of a file, a Dremel and some 400 grit paper, I matched the geometry of the Century parts to that of the original parts.

Now the system seems to be working -- ie, when releasing the hammer and continuing to hold the trigger back, I can now re-set the hammer and the sear holds it as it should. In addition, the trigger is breaking at a about 4 very smoth pounds.

Next step, I'll head the range again this weekend and fully expect that my expensive single shot FAL will operate as it should.

kurt

skfullgun
June 20, 2002, 15:50
Acrobat,
Stimpsoncat gave you excellent info and I'm glad you seem to have it worked out.

I would add one note of caution. When you go to the range to test fire it, load it with a single round to make sure the problem is corrected. If all looks good, load it and shoot it a couple of times with only one extra round in the magazine. It will be a whole lot easier to control if it starts to slam fire with only one round in the magazine....as opposed to twenty!:eek:

Best of luck!

Acrobat
June 21, 2002, 09:53
Thanks for the reminder skfullen,

I always do as you suggested when firing any new (to me) weapon - not just semi-auto's.

I was recently reminded of the value of doing so when I was firing a new handgun and experienced a case rupture.

My hand was blackened and my face spatterd. I hate to think what my day would have been like had a full maginzine been kicked off in the grip...