FAL fcg test

[Pirate]

Took the gun to the range today for testing, had South African 308 with berdan primers
and romanian 8mm to shoot.
Had the gripstick with the FAL fcg, the new recoil spring and the striker type firing pin to
test. loaded a starter belt with 2 rounds and fired those. both fired and the primers looked
good. I fired about 10 more rounds when the gun stopped ejecting. The rear firing pin spring
collapsed, allowind the striker to come out of the bolt wedge. I replaced the spring and fired
another 10 rounds and had the same problem. I put in the 8mm bbl and feed tray / cover
and loaded a couple rounds of 8mm, there was a big difference in the way the gun operated.
The primers looked good no extrusion and they had a nice dimple in them. after a few more
rounds I started having problems with the springs again and tried several different one
but the result was the same after a few shots. the springs are el cheapo ones from the
local hdwe store and are not up to the job that they are doing. I need to get some better
springs and rework the firing pin striker so that it uses one spring and goes into the locking wedge
a little further.
The gun really rocks with 8mm, .308 is a bit wimpy for a gun this size, if I am going to
hump a 20 lb 4' long gun to the range I want a lot of noise & recoil.
The south african ammo is pretty good stuff, I got it from AIM Surpluss, it is relatively cheap $147.00
for 980 rounds, that's .15 per round, I shot a battle pack in my G3 last week and it worked
good in that too.
Using the FAL fcg, is worth the work involved to perfect it. At this point I am not sure if the
gripstick will hold up to lots of long term use without adding sideplates. I plan on cutting up the
FAL lower I have and add a gripstick to it. It will not look a nice as an unmodified one
but I am building a shooter and more concerned with long term reliability than looks.

[BELTLEAD]

Congradulations Pirate! It looks like your FAL idea is going to work after you tweek it

[ak47dennis]

Cool, I have been thinking of using the FAL fire control fpr some time....the AR disconnct does not seem to hold up for me, I have gone thru aprox. 6-8 of them, the wear and allow the hammer to follow thew bolt to close resulting in weak strikes!

Is your fire control from the inch FAL?

[Karbinator]

Very nice looking primers Pirate !!
Is there any chance I could see what that firing pin looks like
that you designed w/original?

Thanks....

[gunslingerdoc]

I should have mine done today (hopefully) and be able to test. My FCG sits and .10 farther to the back than yours appears to. Im not especially worried about durability of the trigger pin hole but since I thined the inside of the grip stick the get the hammer in Im pretty sure that pin hole will give me troublewith 'egging' over time.

Initially I was trying to set it up so that the hammer which is VERY hard could be used with as little modification as possible since many home builders may lack the tools, but I ended up moding it anyway.

I think Ive also come up with a piece that retains the trigger spring plunger, the hammer spring and acts as a sear block, I just have to weld it in the grip stick. Again, Im going for improvements over the original design and trying to simplify production for the home builder. Im still trying bolt extension/FP ideas.....

Good work Pirate!

[Pirate]

Karbinator, this is a photo of the striker / pin. the locking wedge has a 3/16" hole in
it. the fa fp sits in front. using the fa pin gets the fp protrusion right, ,the clearance
around the pin and pin hole is correct and the pin is properly heat treated. eliminates
a lot of work for those who don't have a lathe.
The oa length is determined from your hammer face. the rear washer / striker rear
protrusion is also determined from your hammer face. it is a simple part to make.
Brownells sells the silver brazr compound for $28.00 an oz. You could also try lead
free solder. it is antimony or an alloy of antimony and tin. you can get it at HD or a
plumbing supply.

[Pirate]

GSD, the trigger pin is not a problem, it is the hammer pin that is the problem. while the
parts fit into the gripstick, it is not an optimal setup. the hammer needs a lot of work to
fit. the gripstick also needs several mods. one possible solution for the hammer pin is to
silver braze a couple of #8 washers to the inside of the gripstick. However after building
a working model and testing it I am almost certian it will need sideplates like the AR parts.

[TOM R]

lookin good ,i will be glad to see this project runnin reliable

[gunslingerdoc]

Pirate,

I think that after you get rid of the left 'post' on the hammer you gain over .25 inches laterally. Using this extra space, washers could be used to 'beef up' the holes if they were welded on (from the inside). this way you provide more support and maintain the outer appearence of the grip stick. Yes welding washers inside will be tough (at least for me), but I think you gain the bulk and accompanying support internally vs. externally.

Another option is making an insert box that enclosed the entire FCG and just drops in. All that one would need to do is drill the hammer hole in the grip stick and mill out the space, then drop it in. Perhaps some internal plates would suffice. SO far my proto type seems to work but Im 99.9% sure I'll be reinforcing my pin holes the way Ive done it -- but thats a relatively easy fix.

Tonights plan is the bolt/extension and firing pin....Im debating a stiking rod on the wedge vs a long tradition firing pin sans anti bounce vs. long FP going thru the antibounce....or trying to seduce my wife....Wanna bet I end up getting a more work done on the mg or my wife?

[Pirate]

Doc,
You can silver braze washers inside the gripstick. I know you can trim the side of the hammer
I have built and tested a working unit. it all looks good untill you put it in the gun and
try to make it work.. the hammer needs major modification.

[gunslingerdoc]

Major is realtive. You have to shave the left side down, trim the top, and depending on what angle you set the hammer spring at contour the back side of the hammer so it wont hit the hammer spring when it trys to cock. OF the things Ive spend my time on the hammer took about 20 minutes of grinder time and about 5 minutes again as I played with the hammer spring angle. Now getting a piece that held the trigger spring and served as a base/mount for the hammer spring, that took me quite awhile. So far I its taken me about 4 hours off and on between drilling, milling, welding, grinding, thinking, answering pages and telling the kids they couldnt watch while Im welding to get to a working grip stick. I dont think that's too bad since I started with a FAL lower receiver and a hand full of parts. Hell, I even had to stop to talk with Orin at on point.

Im sure I'll end up doing another one and incorporating changes, but thats part of designing something largely from scratch. Ive also paid attention to your posts and Orin and I have talked way too much about the FCG and the bolt/FP so hopefully the hive mind sessions will save me some trial and error time there.

I will say though that hammer is HARD! Worked out well though since my 120 grit sanding disk polished it like a mirror.