1919 A4 Forums banner

1 - 20 of 64 Posts

·
Premium Member
Joined
·
3,030 Posts
Discussion Starter #1
Traded a semi 1919a4 to another board member. It arrived today and he can't get it into battery. I shipped in two packages - one with the box (internals inside under pressure from the drive rod spring) to his FFL and the barrel, booster and shroud directly to him. The receiving FFL stated that the box arrived well packed and apparently undamaged.

He installed the barrel, booster and shroud and called me because it won't lock up leaving a gap at the bolt face of about 3\8". I have schematics of the a4 on my shop wall, so over the phone I walked him through backing the barrel out far enough that the barrel tenon didn't project past the face of the barrel extension. No joy on lockup.

Had him completely strip the internals, check for anything broken or out of place, then re-install everything without the drive rod and spring. Bolt locks up fine under finger pressure.

So, I had him re-install the drive rod and spring, put the bolt back in, install the back plate and release the spring. No joy there either. Still refuses to go into battery by about 3\8".

I'm stumped and hampered by trying to trouble shoot from 1500 miles away. Put around 400 rounds through this gun over several years and never a problem like this. Do any of you have an idea what is up?
 

·
Premium Member
Joined
·
3,030 Posts
Discussion Starter #3
Osceola, Iowa.

I tried to take headspace out of the equation by having him back the barrel out of the barrel extension until the threaded barrel tenon did not protrude. Was I on the wrong track there?
 

·
Moderator
Joined
·
5,467 Posts
Osceola, Iowa.

I tried to take headspace out of the equation by having him back the barrel out of the barrel extension until the threaded barrel tenon did not protrude. Was I on the wrong track there?
Try this screw the barrel ALL the way into the barrel extension. There will be no lockup unscrew the barrel one click at a time until the you get lockup with the bolt back about 3/4 inch and travelling forward by its own spring pressure. Back out 2 more clicks for .30 caliber and 3 to 4 clicks for 7.62 Unless there's something caught in the booster like packing material this should do it.
 

·
Registered
Joined
·
18 Posts
Hello I am the one who has it now here is a quick photo of its current position





Ill take some photos but it will have to wait till tomorrow I have to work tonight the only way I have gotten the bbl extension to touch the trunnion is by removing the lock frame
 

·
BeltFed GURU
Joined
·
4,277 Posts
ambivolent,
fits with no lock frame that tells me it is the accelerator position when you slide the extension and lock frame in together
it should be un folded with the fingers behind and "under" the pin on left side of barrel extension as you slide it in ,then as you push it home the barrel spring/plunger( rod with spring & pin , pin in cutout on left side of lock frame) is what it keeps the extension and accelerator in the "open " position and forces the extension that last 3/8" closed against the trunnion .Why it is called the barrel spring/plunger !
 

·
Registered
Joined
·
213 Posts
Sounds like a problem with the ass,y process. I snap the lock frame into the barrel ext. and slide it into place so it locks into the side plate. Then slide in the bolt insert the charging handle and it should lock up.
 

·
Registered
Joined
·
4,704 Posts
I'm with the Frog on this one. Sounds like the accelerator isn't in properly, or the plunger popped out of it's slot.
REMEMBER,, DO NOT to put your head behind the gun when the backplate is off!!


Take it apart and start over. It's the only way to be sure. The accelerator fingers have to be 'lying down' until you assemble it to the barrel extension. It'll 'snap' together when you slide it into the box.
When the gun fires, those finger snap open, giving the bolt extra inertia for when it's cold,dirty etc.
That's why it's called an accelerator.
If after all that,it's not closing, it's either gotta be headspace, something stuck in between the booster and barrel or effin' gremlins.
Oh yeah! Make sure the cam in the bottom plate has a tiny bit of wiggle to it. It's not supposed to be tight.


I hope your choice of user name wasn't influenced by this issue. :eek:
It's almost always something simple and usually seems obvious and trivial after you figure it out.
It gets better, trust me.:)
 

·
BeltFed GURU
Joined
·
4,277 Posts
It could be one other thing the breech block is in backwards ,looking at the extension over the tail towards the barrel threads and the breech lock should have the beveled top edge facing the threaded end of the extension !!

If it is not the gun will do exactly as you have happening , the breech lock is being stopped by the breech cam ramp and jambed up against the bottom of the bolt hanging you up 3/8" our of battery !! It is a small thing but it does make a big difference !!!

I would bet that is the problem if it came in "pieces " and the dealer turned it around .....:rolleyes: with little or no experience with a 1919A4 !

As you can see have been pondering it all night :confused: ........
 

·
Registered
Joined
·
18 Posts
I think I found the problem, i think its in the trigger I removed the trigger installed the bbl extension and lock frame tripped the accelerator and lock frame went fully forward it appears that the accelerator has not been widened to allow the trigger to pass through



 

·
Registered
Joined
·
198 Posts
One of mine did this after tearing it down and taking it to the range. Tearing it down again and putting it back together solved the issue. Never 100% sure what it was, but it was all good afterwords.
 

·
Premium Member
Joined
·
3,030 Posts
Discussion Starter #13
The thing that is so odd is that this was a working gun when I removed the barrel and shroud for shipping. Didn't mess with the internals at all. It should have gone right together by simply screwing the barrel in (it has a USGI profile indexing spring so you can do that) then putting on the shroud and booster. Can't imagine that any additional machining is necessary.

If it doesn't go together today let me know and I'll set up sending it to a reputable builder close to you for repair.
 

·
Registered
Joined
·
2,001 Posts
I think I found the problem, i think its in the trigger I removed the trigger installed the bbl extension and lock frame tripped the accelerator and lock frame went fully forward it appears that the accelerator has not been widened to allow the trigger to pass through

If it is the accelerator, you can open it up more. A Dremel tool, a file, or mill works best. But it's one of those things where clearance is needed. Too little is more of a problem than too much. Easiest fix would be a mill with a carbide end mill. Can someone add in how wide the slot should be? As time goes on you will start to accumulate extra little parts.

Is anybody close to the border of Missouri and cornfields :) that can help hands on? I'm sure he would like to be able to shoot over the weekend, too far from our little group.

Be sure to keep us posted, your new status makes it a bit harder for the experts to contact you.
 

·
Registered
Joined
·
213 Posts
That was what I thought d dog I still think it in the ass,y procedure The bolt should be put in last with the lock frame and barrel ext. locked together with the accelerator loaded should be put in the gun first.
 

·
Registered
Joined
·
18 Posts
Here are a few more photos there is a wear pattern on the accelerator that suggest that the trigger was riding against it, I have assembled this using ironcreations re-assembly video on youtube as a reference, also how much travel Should I be getting on the trigger bar the pictures show it at its height of travel when installed in the receiver.










 

·
Registered
Joined
·
4,704 Posts
Well hmmm.
The breech block is facing bevel up and forward as it should be.
I can't tell from the pic angle if the trigger is high enough.
It looks to have plenty of clearance between the accelerator fingers.
The 'T' part of the trigger bar travels over those fingers anyhow, not between them. Don't cut them off! :)
It does however need clearance in the bolt. I can't see the fit in the bolt from pics. I'll review my AGI 1919 vid tomorrow to see it that shakes anything helpful loose from my brain.
He has a nice HUGE armorers display of internals in it.
 

·
Registered
Joined
·
1,499 Posts
I thought it was the breech lock but as long as the chamfer is to the front of the gun it's ok. Going to look one over for a coffee or two.
 

·
Registered
Joined
·
843 Posts
To me it looks like the accelerator has not been modified for semi looking at your pics. Who's trigger and sear? Not sure if anyone asked yet.
 

·
Registered
Joined
·
213 Posts
As devil dog said it worked when it was torn down. every thing in the pics look fine.I would not alter any parts. double check your ass,y order it is critical to get it into battery. J.R.
 
1 - 20 of 64 Posts
Top