Another 250 rounds of .308

[Pirate]

Went to the range today and did more testing. Started out with 8mm and had some
binding problems with the hammer, I added some weld to it to increase the mass and
it was causing problems. I cleaned up the hammer and still had misfires, so I switched to
.308 and still had misfires. I took out the new striker and put the old one back in and ripped
through a 50 round belt non stop. Put in another and ripped through that as well, the other
people there thought I was nuts, by now the gun was smokin' dirt was flying, and empties
were rolling off the bench. Then it was Stifeouts turn to do 50 and he ripped through those.
I shot another 50 rounds and by then the gun was to hot to shoot. After the gun cooled off,
I put in the last belt of .308 and halfway through the hammer broke ending the test.
After today, I am totally convinced the FAL fcg is the way to go and will start work on an
improved more refined version. I am sure the gun will run with any kind of ammo with these
improvements.

[none123]

sounds like the fal fcg is deff the way to go... Was there any difference between the wedge that was causing problems and the one that worked? also what was the cause for the hammer breaking?

so did you let the beer looter shoot any as well?

[Pirate]

The striker was to tight, when I drilled the wedge and feed stud I used a 3/16" drill, the
rod I am using is 3/16" as well, so it has to be polished down for clearance. It was a bit
to tight. As for the hammer after welding I quenched it and it was to hard, it snapped off.

[gunslingerdoc]

I went out the other day and was plagued by ftf's. I had repalced my bolt extension and cleaned up the hammer re-cocking pad and cocking handle bar. I did make my 'wedge hole' larger when I drilled mine and I tappered the firing pin end when I initially set it up. I think the issues I was having were related to the ejector bar binding on the firing pin - I could get a few to go bang when I recocked the hammer, but not all. Im thinking of grinding down the tops of my round spacers in order to guarentee there is plenty of space for everything.

I did have a few primers that wanted to start floating back out so Im pretty sure I have to tweak my spring tension as the spacer/spring bears on the wedge - Im just concerned about slam fires.

Any thoughts there?

How have you solved the recoil spring trying to poke into the extension or getting off center enough to block the buffer? I tried making some tack weld holders but my sucess has been hit or miss - I thinking of welding the spring on to the extension and being done with it.

Hey, and were did the tape go?

[Pirate]

GSD,
1. copy the striker I made there is a dwg and photos, use #8 flat washers for the stops.
2. use a spoon shaped ejector extension, with the striker I made there is no interference
with the ejector bar.3. The striker bar must be LOOSE in the wedge and in the bolt feed
stud. with the bolt in the gun push the striker forward and meke sure there is no binding
and that it floats back and forth freely.
3. do not try to weld the spring, it will break. I made a step in the bolt extension to retain the
spring so the 2 flat coils go in . this is important as you have discovered to prevent
the spring from binding on the buffer.
as for the primers you may have to heavy of a return spring. the spring does not need to
be real strong. the whole purpose of the fal fcg iis to keep pressure on the primer to
prevent blow outs. a small bit of extrusion will occur but it should not be more than a couple
of thousandths.

I will be working on improving the bolt extension as soon as I have it worked out I will post
photos and dimentions.
My gun is about 95% reliable, as soon as it is 100% I will post the details so all can avoid
all the problems I have had to solve.

I stretched the bbl latch spring to eliminate the tape, it catches fire after 200 rapid rounds!!

[gunslingerdoc]

Pirate,

Im using a flat ejector extension bar. I just read your other post and I see that your rear spacer fits inside the ejector sleeve. The one I have simply butts up to the feed stud --actually my feed stud just extends into the extension enough to hold the ejector sleeve since it cracked when I was drilling it. If you look at the pics I posted I have a rear spacer, spring and then a thicker front spacer that is not fixed to the FP. Im still trying to get the spring tension/purpose down. Too much and the wedge is held too far forward, yet you want enough to keep the (new) firing pin to the rear so its not pushing on the wedge. While I like this idea/system this is the core issue I have with it - I dont want to be making something the goes bang unintentionally. What are your thoughts?

Do you think the rear spacer has to go into the ejector sleeve? We both accomplish the same thing just our methods of retention are different. (and I really dont want to try to drill thru another damn feed pin - ouch!)

I think youre correct in the issue being a case of the FP binding on the ejector. I may try flattening the top of the spacers and seeing if that solves the problem.

The feed pin stud committing suicide led me to using the flat ejector bar. I saw how you bevelled the rear of your extension to get the spring to stay fixed - I tried to accomplish this with a few tack welds around the back - no consistant luck. I may try a sleeve that accomplishes the same thing or I may bore the rear out a bit to match your set up.

Thankfully my new parts arrived today so I can quit remodifying the same parts over and over and start anew with the needed changes.

How many coils did yu chop for the recoil spring? I think I chopped 4.5 and it worked first outing, but then I had to make it better---DOH!

"The enemy of good is better."

[Pirate]

GSD,
Personally I would discard the ejector bar and striker you have made. I went that route
and after lots of work got nowhere with it. The one that I am using now works well.
1. if your feed stud is missing you need something to center and hold the striker. You can
make a bushing to fit inside the ejector sleeve, it could be as simple as a washer. for
test porposes you can solder it in using electronic rosin core solder. silver brazing paste
from brownells would be the proper way to do it.
2. discard the ejector extension and get a spoon shaped one, it will eliminate binding problems
I wasted a lot of time with that too..
3. the striker length is critical, if it is to long even by only 1/16" it will cause a problem.
4. you only need a fairly light spring to push back the striker, ,so get a small hdwe spring
for testing. be sure to lube the fa fp to prevent sticking.
5. make sure the striker moves freely with the bolt locked in the gun. you should have at
least .005 clearance.
6. harden the ends and slightly bevel them.
7. I don't know what you are using for a bolt extension, post a pic and possibly I can help
with that also.

keep in mind the simpler you make these parts the better they will work. when I simpified
my parts the gun started working.

[gunslingerdoc]

Pirate,

Is the striker/FP your using the one pictured in your FAL fcg test post?

I can weld a new end onto my feed stud (I'll even use something softer) and drill a hole thru it.

Im using an extension similar to yours (same dimensioned tubing). I started with a piece of square tubing which actually helped to center the spring better and gave me better clearance above and below, but I was having internal clearance issues with the buffer. I did dremel some material out of the inside which helped, but it was half assed so I decided to use round tubing to get around the buffer clearence issue. Of course I got 20 rounds off with no problems after everything functioned 'dry' at home with that set up. Then I decided to make it better - oops!

I think if I had unlimited time and more access to better tooling, I would go with square tubing over round, using thicker walled stuff and bore the ID out to fit the buffer, but I dont. The square tubing allowed me to cut a notch for the spring and it held it perfect.

How much interaction is there between your ejector 'collar' (the part secured by the feed stud that is struck by the booster)?

Have you settled on a correct recoils spring coils to 'chop'?

Im hoping tonight or tomorrow to get some time to set down and work on my 'new parts' Im thinking Im at a point where Ive refit/reground/moved and otherwise screwed with the parts I have been using that alot of issues will go away if I start from new stuff - that and I tired of grinding....

Let me make sure I understand your FP set up

1. your rear spacer fits inside of the ejector collar and rearward travel is limited by a hole thru the feed stud.
2. the front spacer just serves to center the FP with the wedge and a base for the spring.
3. the springs purpose is to hold the firing pin (yours) off the wedge, but is weak enough the hammer striking the firing pin over comes its tension so the firing pin can hit the wedge hard enough to slam the wedge and its FP into the primer.

How much does your spring bear against the wedge?
Have you noticed any difference in function if you totally omit the spring?

[Pirate]

GSD,
1. the striker is the one in the fal fcg test. there is a dwg posted of it on my build tutorial
page 7. the rear washer sits against the feed stud and limits rearward travel. The front
washer seats the striker return spring. the striker goes through the bolt wedge and should
fit looselt, also in the rear through the feed stud.

2. I don'y understand the question about the interaction of the feed collar. it should
go all the wat forward for proper ejection. if the collar is not hitting the buffer the bolt
extension is to long or your spring is to long. there are 19 coils on my spring. I would
strongly recommend getting a brand new spring. my old one was severely collapsed
and it is a very important part.

3. as for the bolt ext, I agree with you that the current style I am using could be better,
I have had a few problems with mine and am waiting on material to make a new style.
it will work a lot better, as soon as it is tested I will post photos, possibly get some
made for sale.

4. the front spacer only hold the fp spring. the striker is suspended in the feed stud
and bolt wedge. the washers do not touch anything. use #8 flat washers, grind down
the rear one the front is ok as is.

5. you need the striker spring to eliminate the possibility of slam fires, it does not need to
be real strong spring.

there will be a builders chat tomorrow night at 8pm log on and I can answer your questions

[gunslingerdoc]

Pirate,

My feed stud question was founded in concerns about friction on the firing pin by assorted parts thereby limiting its inertia. I was trying to ask if your rear spacer touched the collar or if the only place it touched in the rear was where it went thru the feed stud.

Look at using some thick walled square tubing for an extension and boring it out to fit the booster. You have more machining capacity so its worth a look. The piece I used was a piece of scrap I picked up at my welding instructors shop.

As an aside...

Last night I was working on my new and improved grip stick/fal fcg. To start I filled the entire front end up with weld and built up the front end of the grip stick until it was square with the top. I also filled in the inside so the whole top have was the thickness of the double walled sections. Then I chucked a 1/4 endmill in the drill press and went to town. So now I have much thicker side walls. For the front attachment point, I just cut the notch with my 4 inch angle grinder and shaped it. THe front end went very quick. Any way I think this will fix/answer our concerns about egging out holes.

I may come to play tonight at 8pm, but will see what plans the family has...Plus if I can get everything done, Im planning on testing tomorrow night!

The real question we have to ask is when are we gunna quit with all this extension crap and go with a striker set up that mounts in the bolt carrier? I keep finding myself coming up with improvements newer designs before I finish the last one!

[Pirate]

GSD,
1. the striker rests against the feed stud, it does not touch the collar. obviouslt any
binding needs to be eliminated, but the striker needs to be properly located and held
by the hole in the feed stud.

2,. I am working on a new style bolt extension, have material coming and hope to
have a prototype late next week.

3. a good rule to follow is that if it works any attempt to make it work better will ruin it
Been there many times!!!

4. A bolt carrier striker arrangement has numerous problems to overcome. since the
carrier sits over the ejection port a relaese mechanism will be difficult. also the parts
will need to be precision and properly heat treated . The amount of R&D involved
would outweigh simply improving the bolt extension. Also the design would have to
be submitted to BATF for approval.

based on the results of my R&D so far I think a properly installed FAL fcg and improved
bolt extension and striker will result in a gun that is 100% reliable with all ammo. I have
been working on this project for a few months and feel a perfected conversion is very
close to being completed.

[j. bergmann]

gunslinger , here is what i did for my buffer. i made a new nose peice that has a taper too it so it guide's into the bolt extension better. I tell ya , it nice having a mill and a lathe!!!oh , and the buffer bolt is drilled and the hole beveled also . i didn't want anything touch'n when stuff is banging around.john

[gunslingerdoc]

J.B.,

I Modified mine similarly - I ran a bead around the opening (extended it toward the ejector collar about 1/8 inches) and drilled a 1/4 inch hole in the screw about 3/16 deep. I havent bevelled mine as much as yours but that could happen.

Thanks for the pic

[drooling idiot]

i was considering cutting the buffer spring down by 3/8 " and fabing a new 3/8 " longer nose piece for the buffer with a similar taper . same OAL but a deeper pocket to prevent FP problems.

its funny that brp never thought of this stuff.