issues with the gun firing after assembly. a little help?

Hello

It's hard to tell what is going on. When the bolt closes, is the cartridge missing the chamber? Or is is getting stuck
partially in the chamber at an angle? I think if you can take a still, close up photo of the stuck cartridge, it would help.

Another question. If you put a single round in the magazine, will it feed correctly and fire?

Hiya Romagnus,

Is the magazine that tight a fit you HAVE to bang it into the mag'well Could be worth checking that the feed lips haven't been flattened due to the mag being thumped against the closed bolt
If the lips are bent the round won't sit at the right angle and won't be stripped out correctly maybe.
My MGC Thompson's mag feed lips got bent lke that and wouldn't feed right.

My factory assembled Grease Gun's mag only needs to be slid into the well until it clicks the catch.
I've also found with all my guns that inserting the mag with the bolt open is easier than when the bolt's closed.
It does look like the cartridge isn't being fed all the way into the chamber, as Fledermaus says is the cartridge jamming part way in

it seems like the round isn't getting pushed all the way in. i am going to try an adjustment in the next few days and will let you know.

I posted a response to your "Instructions" , I noticed your kit's diagrams show the old Open Cartridges and Detonator Pin...
You won't have open cartridges otherwise you'd have questioned the loading guide I sent you but I assume the Detonator Pin your gun has is Not the Open Cart. type is it

Another thought, the Hudson c.p. inner pistons are shorter than MGC types. They can tip over in the cartridge body and jam up...
Try loading the cartridge by gently pushing the piston all the way down until it almost touches the cap then screw the top on.
Will the cartridge feed into the chamber now

well I tried adjusting the feed ramp in the barrel but no change. itappears that the bolt slows down conciderably as soon as it makes contact with the magazine. it fires fine with the magazine removed. the carts are going onto the detonator pin fine, just not with enough force. I will see if I can modify/shave any parts to help it move along.

I'll take some photos of my Grease Gun's magazine today. Hopefully I can show you how the cartridges sit in the lips.

Maybe rubbing down the lips' edges will help Any burrs or rough edges there might be grabbing the cartridges.

I'll measure the mag spring free length too,

I took apart my mag today and lubed the sides and even filed down some corners. I did find the ejector rubbing on the bolt so I took care of that. It really hits hard until the magazine is in place. I did get it to fire from the magazine once but then I loaded 5 rounds and it did like before. believe it or not, this is a fun part of model guns for me, trying to figure it out!

As promised, here are those photos of my Grease Gun's mag...













The spring's free length is 425mm

Hudson did re-work the magazine recently (ref http://mp40modelguns.forumotion.net/modelgun-news-f3/hudson-m3a1-news-t642.htm ) I would assume mine has the older magazine and there's a possibility yours will be the new one.
I can tell you though that mine feeds well and fires consistently.

Hope this helps

hey! in the 4th picture down the bullet feed in the magazine looks like there is a groove cut into it to the right of the "bullet". Is that a groove cut into it? That is exactly where my bolt hits mine and slows down! I have wear marks on mine. If yours is grooved I will file mine down!

Is this the groove you've spotted


The follower is a plastic moulding on mine, and I can't recall if it was grooved when it was new or not
I'm inclined to think now, especially as you say your's is showing signs of scratches, that the bolt's feed ramps have been rubbing through it over time.
I would've thought that the bolt would only rub along the follower when

• the bolt closes after the last round's been fired
  
  
• dry firing with an empty mag
  

A loaded mag would push the follower down into the mag's body and well out of the way wouldn't it

Is your bolt is being stopped dead, or slowed right down as it runs over a loaded magazine
Does the bolt get stopped / slowed by an empty mag
Your bolt slams shut without the mag doesn't it
Could the mag' be sitting too high into the receiver

i understand what you mean. my bolt slows down weather themag is full or empty. i tried firing with the magazine not fully seated and it still wouldn't load right. i think i will find some stronger springs for the bolt, they could be just weak.

You would think that the springs supplied in the kit should be up to the job as they're brand new wouldn't you
As long as they are stored without any tension on them they ought to be fine

I used to keep my steel STEN stored fully assembled, but with the bolt closed thinking that there wouldn't be enough tension on the recoil spring to cause problems.
Later attempts at firing would have the bolt slow to a stop as it struggled to strip a round out of the magazine. Much the same problem as you describe with your M3 now.

I found that the spring had become coil bound and wasn't strong enough to overcome the mag spring pressure. Take a look at this photo...


A new spring cured the problem instantly. I would have expected the spring to be damaged if the gun had been stored with the bolt cocked or way back in Safety but not just assembled. I store the STEN without it's recoil spring now
That said, it's the only instance I've had with this problem. All my other models are stored assembled and fire OK.

If you place a round in the chamber by hand, remove the mag and pull the trigger it'll fire and extract / eject fine won't it
There's no possibility of any moulding flash, high spots, burrs etc around the breach, mag well, ejection port that's fouling the bolt enough to slow it down that much

Could you slip some tubing over the recoil spring guide rods to put some pre-load on them
That might make them a little "stiffer" but might be too strong for the blow-back...

Ok. The problem is with the springs. I took some automotive plastic vacuum tubeing and drilled out the center and cut to equal length. I inserted them on the rods and here you can see the final out come that actually startled me! You can see me jump because I was sooo not expecting it! enjoy....

oh you can`t beat the sound of those heavy rounds thwacking into walls etc

Mate ..there is some weirdness happening with your barrel nut too ...


DOC