Is this "normal" for this pump shotgun? (PIC)

[mick53]

Hi,

The shotgun in question is a Stevens Model 620, manufactured in 1952.

I had it out today and noticed that, after firing, the ejection port was opened up part way (pic at the end of the post).

So I started conscioulsy to keep the arm that supports the forend rigid after every shot and found that the ejection port did not open when I did this.

But, if I "relaxed" the support arm, the ejection port would partially open. Is this normal???

This model shotgun breaks down beautifully and simply. Just open the action all the way, twist the magazine tube, and it comes apart. It's a great feature.

Anyway, after I ran out of shells and I was breaking down the shotgun to put in the case I noticed the magazine tube was not tightened all the way.

So I'm wondering if the "loose" magazine tube might be the cause of the ejection port partially opening up after firing?

I'm also wondering if I didn't tighten the magazine tube down all the way when I was preparing to shoot, OR, if the firing might have loosened it up? I'm usually carefull about tightening it up well before I shoot it.

I'm hoping the "620 man," Lee Lapin will see this and give an opinion.

Anyway, here is a pic of what the receiver and ejection port looked like after firing. The pic is a staged reproduction using a snap cap, but this is how it looked.



Thanks fellas,

Mick

 

[theman838]

Edit: Oops.

 

[rcmodel]

cause of the ejection port partially opening up after firing

What you have is the bolt unlocking and opening part way.
Not, the ejection port opening.

That the bolt didn't slam open violently and eject the case leads me to believe it locked properly in the receiver at firing.
Then released properly after firing so you are able to pump it again.
That is normal.

Model 1200 Winchester pumps open so fast with Magnum shells it almost wears blisters on your hand from the forend checkering slipping through it.

rc

 

[mick53]

Wow, talk about two differing opinions!

I do hope this is normal.

Lee Lapin, I need ya, buddy!

Mick

 

[4thPointOfContact]

BEFORE you pull the trigger, does the bolt lock up tight?

 

[mick53]

Locks up tight as the proverbial drum.

It may be germane to know that I was loading and firing one shell, a single shell, at a time. I never had two in the magazine. Just one.

 

[Milkmaster]

As long as it is locked up tight before you fire and only opens AFTER you fire, then you are good to go in my opinion. I have an older 870 that will fall almost all the way open when you stand it in the corner, but it locks tight when loaded for shooting.

 

[Fred Fuller]

Mick,

A couple of things here, to keep in mind. #1, I don't have so much as an owners manual for the 520/620, much less the equivalent of the Kunhausen shop manual for the 870 that I depend on to tell me what is and isn't supposed to happen with that particular shotgun.

#2, keep in mind what we're talking about here is essentially a 1903 design - that was the date of JMB's patent for what became the Stevens 520, which is mechanically pretty much the same gun as the 620. Pump shotguns were new ideas back then, and the 520's patent is only ten years newer than Browning's patent for what became the Winchester 1893 (soon revised as the 1897) pump shotgun, which was the first widely successful pumpgun in the US. It was predated by the Spencer and the Burgess pumps, but those did not achieve anything like the sales of the '97. And as they say, things were different then.

The 620 is a slam-fire design, that is, it has no disconnector that mechanically requires a separate pull of the trigger to fire another shot after the action is cycled. What the 520/620 does have is variously referred to as an interrupter or safety interlock, that is intended to prevent the hammer from falling until the bolt is fully forward and securely locked. It does not require a separate pull of the trigger to fire another round, if there was one in the magazine when the action was cycled, which is what makes it a slam-fire design.

And also according to Swearengen, the design has a recoil interlock mechanism, intended to unlock the action/forearm upon recoil. This usually happens due to an almost imperceptible forward movement of the forearm as it is held in in the shooter's hand as the rest of the gun recoils back. Even with no hand on the forearm, the gun is going to recoil 'inside the forearm tube', effectively moving the forearm forward to unlock the action. I'd say what you described was to be expected, and is normal.

Try this. With the gun empty (check visually and with a finger, both magazine and chamber), point in a safe direction, push the safety off, and with the bolt forward and locked/hammer cocked, pull back firmly (not gorilla grip, just firmly) on the forearm and then pull the trigger. I would expect the action to stay locked until you move the forearm forward a tiny fraction of an inch. That's how the 870 works, and I would anticipate a properly functioning 620 to work the same way. But I stand to be corrected, if anyone comes along who is more familiar with the design than I am.

hth,

lpl

 

[HGM22]

I posted a similar thread after seeing this occur in a Hickok45 video and the majority think its just fine. I'm inclined to agree as long as its not opening during firing.

 

[b.thomas]

Perfectly normal!
I have a 35 year old old Wingmaster that will do the same thing.
It's a matter of having a well used, smooth opperating action.....................plus the recoil of the shotgun.

 

[Hunterdad]

As stated above, as long as its locking up when you put a round in the chamber, you are good to go.
When I went out this past year to sight in my slug gun with Remington Buckhammers I had a similar issue. For the first couple of shots, I was not putting my hand on theforend, when I would fire, the round would eject itself. I thought something was wring too until I figured out the recoil itself would open it up.

 

[mick53]

Try this. With the gun empty (check visually and with a finger, both magazine and chamber), point in a safe direction, push the safety off, and with the bolt forward and locked/hammer cocked, pull back firmly (not gorilla grip, just firmly) on the forearm and then pull the trigger. I would expect the action to stay locked until you move the forearm forward a tiny fraction of an inch. That's how the 870 works, and I would anticipate a properly functioning 620 to work the same way. But I stand to be corrected, if anyone comes along who is more familiar with the design than I am.

hth,

lpl

Lee, I did the test following your directions.

Upon cocking the shotgun, I noted the action release drops down.

Next, I pulled the trigger while applying rearward pressure (pulling the foreand back towards me) I heard the firing pin hit the snap cap. So yes, it fired. Upon firing, the action release button moves forward.".

At this point I was not able to open the action by pulling the forend back.

Next, after applying a bit of forward pressure, the forend moves some very small fraction of an inch forward, there is an audible "click." The action release button moves up and into the reciever when the forward pressure is applied and the action is free to where the forend can be pulled rearward to cock the shotgun.

Upon cocking, after pulling the trigger,the action release button appears to move rearward ever so slightly and the whole cycle can be repeated.

I realize I'm being more than a bit cautious about this, but better safe than sorry has always been my motto.

I think what is happening is when I fire the shotgun with my hand gripping the forened, the initial reaward momentum sends the gripped forend forward and frees up the action release button.

Then, the rearward momentum bounces the shotgun off my hold sending the shotgun forward slightly(and thus the forearm which is still in my grip moves rearward) and the action opens some.

Does this sound like what's happening to you?

Mick

 

[inthedark]

Lee Lapin has hit the nail on the head. You don't have any problem. I get the same concerns every year from the guys during annual requals about the 870's and some of their personal shotguns that they bring in. Owners of the Ithaca 37 will have the same event happen with them. Chimo ITD

 

[Virginian]

You don't need your hand on the fore end at all to make this happen. It's the weight of the fore end, action bars, and bolt and their inertia. When the gun recoils, this weight tries to stay forward, and then after it is moving to the rear under recoil, you stop the receiver and the bolt continues to the rear. If I shoot my Wingmaster without holding the fore end it will eject the shell every time.

 

[BADUNAME37]

Any pump action shotgun I have ever owned would automatically open upon shooting if I were not holding the forearm closed by holding tightly and pressing forward.

 

[Carl N. Brown]

I have observed the same with other models of pump shotgun. It is easy to see that the bolt of my old S&W 916 tilts up and securely locks, but fired one handed or lightly gripped, it opens under recoil. There is no swelling of empties so peak pressure is long past before the bolt opens.

The Winchester Model 1200 pump action shotgun was developed in parallel with the Winchester Model 1400 semi-auto shotgun; (Numrich Gun Parts Corp. Firearms Parts Catalog lists a number of parts in common between the two models.) I have heard at least one owner of a 1200 brag they could pump off a repeat shot faster than a semi-auto.

It appears to me that it is common for pump-action bolts to unlock and start ejection under recoil.

 

[Fred Fuller]

Mick,

That sounds like everything is working as it should be. Enjoy it, it's a great shotgun.

Every time I think about the detail of his his designs, it reminds me what a genius John Moses Browning really was...