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Discussion Starter · #1 ·
Hello All.

I have an older SKB gas operated semiauto 12 gauge. It appears to be the same model as the Ithaca XL900.

It's in overall really good condition (I bought it used). I've shot quite a bit of clays with it and it's always functioned well. I have always wondered what condition the recoil spring and tube were in since I never touched that assembly in the many years I've owned the gun and I'm guessing it may have never been serviced.

Long story short the spring and tube and such looked in good clean condition. Based on the dry hard grease caked on the tube and such it appears nothing has been touched since it left the factory. I cleaned everything up, put a bit of light lube on the parts and put everything back together.

All seems to work and cycle fine now except the bolt will not stay back when I pull it back by hand:

1) Is there any connection at all between the recoil spring assembly and the bolt locking back? My recollection is that it locked back fine prior to my messing with the recoil spring. I haven't had it out of the safe for a few years however so my memory could be off. It's possible it was acting up when I put it away long ago but I'm thinking not.

2) I don't know the part name but there is the flat "rod" that engages with the bolt release button. It springs out to stop the bolt then goes flush against the receiver when the release button is pushed so the bolt can slam forward. At quick glance that seems to be moving freely both in and out. Sometimes it will hold the bolt back for several seconds before it slams shut. Is it possible/probable the tip of the rod or such is worn to the point where it can no longer hold the bolt back? I'm not sure where exactly on the bolt or bolt slide assembly that rod tip engages to hold the bolt back until the button is pushed. Maybe there is an issue at that junction letting the bolt slip by.

3) Whether the gun is cocked or uncocked when I pull the bolt back seems to make no difference. It slams shut.

4) Does anything in the trigger group play a role in locking back the bolt? Maybe something out of sync?

Any direction is appreciated. It seems to be a new issue related to my messing with the recoil spring although I can't see how the two are connected.

Thank you!
 

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This is the “tricky” part when re-assembling the 300-900-1300-1900-3000 series of SKB semi autos
With the trigger assembly out and the bolt assembly in place; pull the bolt back about half way and then install the trigger assembly. The trigger assembly doesn’t always want to “seat properly, and the two pin holes are therefore not aligned. Be patient and with practice you will get the hang of this. I’ve seen guns where these pins are damaged because guys haven’t figured out how to engage the bolt assembly with the
 

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Discussion Starter · #3 ·
Thank you Pumped. I'll give that a try today. Since my original post I took the trigger group out to see if I could spot anything obvious. If I put the group back in the bolt is now locked tightly closed - just the opposite of the original problem. I drop the trigger group out and the bolt cycles fine by hand. Reinstall and bolt won't move...

As you suggest something does indeed seem to be out of alignment. The really frustrating part is I've taken this very gun apart and out back together several times in the past without an issue. I'm not sure what I'm doing different this time.

I'll give the bolt half back suggestion a try.
 

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Advise if you have success trying this. I've taken a number if these guns apart; many were filthy, as they had a reputation of being difficult to put back together; this was the main issue, and on some the bolt handle was held in by a small detent on the back side of the bolt assm, you need a pick to push in the detent while pulling out the handle; others you just centered the slide bar over the bolt and pull out the handle.
once you get the hang of pulling the bolt back while inserting the trigger assm, so the bolt will properly lock in place, it becomes easier. If you still have trouble, I can try to put a short video together for you
Really a overall simple and well built gun; a lot to like about them; just a couple of quirks that are easily mastered (after some frustration) Also difficult to find any tear down instructions, etc on these guns. I buy parts from SKB Nebraska, and they were kind enough to send me an owners manual (without asking!), but as with most manuals, not really any help beyond the basics
 

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one other thought; make sure you are installing the link the right way; you likely are, since you've had this apart a number of times. SKB does have a parts schematic on their website; great to have that!
 

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Discussion Starter · #6 ·
Hello Pumped.

Thank you for the detail. Yes - your suggestion worked. I now have my trigger group installed and the bolt assembly slides back and forth smoothly. Thank you again.

My original problem remains however where the bolt will not stay locked back. Do you have any suggestions for that? I've tried to figure out for myself exactly how that mechanism is supposed to work to no avail. It would seem something is worn, bent or broken.

Thank you again.
 

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Hello All.

I have an older SKB gas operated semiauto 12 gauge. It appears to be the same model as the Ithaca XL900.

It's in overall really good condition (I bought it used). I've shot quite a bit of clays with it and it's always functioned well. I have always wondered what condition the recoil spring and tube were in since I never touched that assembly in the many years I've owned the gun and I'm guessing it may have never been serviced.

Long story short the spring and tube and such looked in good clean condition. Based on the dry hard grease caked on the tube and such it appears nothing has been touched since it left the factory. I cleaned everything up, put a bit of light lube on the parts and put everything back together.

All seems to work and cycle fine now except the bolt will not stay back when I pull it back by hand:

1) Is there any connection at all between the recoil spring assembly and the bolt locking back? My recollection is that it locked back fine prior to my messing with the recoil spring. I haven't had it out of the safe for a few years however so my memory could be off. It's possible it was acting up when I put it away long ago but I'm thinking not.

2) I don't know the part name but there is the flat "rod" that engages with the bolt release button. It springs out to stop the bolt then goes flush against the receiver when the release button is pushed so the bolt can slam forward. At quick glance that seems to be moving freely both in and out. Sometimes it will hold the bolt back for several seconds before it slams shut. Is it possible/probable the tip of the rod or such is worn to the point where it can no longer hold the bolt back? I'm not sure where exactly on the bolt or bolt slide assembly that rod tip engages to hold the bolt back until the button is pushed. Maybe there is an issue at that junction letting the bolt slip by.

3) Whether the gun is cocked or uncocked when I pull the bolt back seems to make no difference. It slams shut.

4) Does anything in the trigger group play a role in locking back the bolt? Maybe something out of sync?

Any direction is appreciated. It seems to be a new issue related to my messing with the recoil spring although I can't see how the two are connected.

Thank you!
I make no claims as to being an expert, but I'll try to help. I've never seen an SKB auto, but I think it must have some things in common with other autoloaders. I'll try to help you figure out the problem. Since I don't have the gun here to look at, you'll have to do the looking.

First, you need to remove the trigger assembly. Then, while pressing in on the bolt release button, you should see a flat bar that runs longitudinally inside the receiver. This bar should move when you press on the bolt release button. This bar also likely controls the release of the next shell out of the magazine.

Once you've located this bar and watched how it moves when you push in on the bolt release button, this should indicate to you what part of the trigger assembly it would contact when the shell moving out of the magazine contacts the bar and causes it to move just as if you were pushing in on the bolt release button.

Once you've identified the location and part on the trigger assembly that is actuated by this bar, then I think you will identify the part that is defective or not correctly installed. Sometimes a little spring may be missing or something not installed correctly on the trigger assembly.

I can't be any more specific than this without seeing the gun. And it's possible that the gun may have some other method of correlating the movement of a shell out of the magazine with the activation of the bolt release button other than a flat bar, but if so, this should be apparent to you upon examination of the gun.

Just keep this point in mind: When a shell comes out of the magazine, then the bolt release button is activated and this, in turn, releases the bolt to come forward and chamber the newly released round. OTOH, when nothing comes out of the magazine, nothing should activate the bolt release button, and therefore the bolt should remain locked to the rear... providing of course that the bar activates something in the trigger assembly which will lock the bolt to the rear.

In your gun, something is broken, missing, or incorrectly installed which interrupts this sequence of events/action and allows the bolt to come forward rather than being locked to the rear as it should be when the last shell has been fired. Now it's your job to find out what this "something" is. Good luck.
 

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Discussion Starter · #8 ·
Thank you Ulysses. Your write up gave me a good picture of how how things should work regarding the bolt lock back on a typical semi-auto. I've never explored it much because I didn't have to.

My SKB is still a bit of a puzzle. The flat bar seems to move as it should. The default position is the bar extends into the receiver. I assume that is meant to block the bolt from coming forward - keeping it "locked" back. When I push the bolt release button the bar goes flush against the receiver. I assume this gets it out of the way and lets the bolt mechanism slam shut. All as you describe above.

The puzzle is the flat bar does not appear to block anything on my gun. When it extends into the receiver the tip of the bar falls exactly in front of the lead edge of the main metal trigger assembly casting. It doesn't engage with anything at all in the trigger assembly.

The bar also appears to be positioned well below the bolt assembly without engaging it in anyway. The bolt is free to cycle back and forth with plenty of clearance from the lock back bar.

I'll explore further. I have a Beretta semi-auto I can take a look at to see how their lock back works. It seems something is maybe missing or worn or such. Except for the lock back the gun functions as it should when I cycle everything manually and dry fire.

Thank you again.
 

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This is undoubtedly a useless comment but I will give it a try anyway. Does that model gun require that the carrier release at the bottom or somewhere be pushed first before the bolt will lock back? Like all the Beretta semi autos that have that feature.
 

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Discussion Starter · #10 ·
I haven't shot it in a long while oyeme but as I recall no - nothing has to be pushed to pull and lock the bolt back. I'll take a look though and give it a try just in case. I appreciate the suggestion.

I do seem to remember the carrier latch button has to be pushed and held in each time a shell is loaded into the magazine which I think is unique to this gun.
 

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I took apart one of my XL 900's and put it back together, to remember how to engage the trigger & bolt assm.
Took some pictures that i will try to post here. Here is a brief step by step;
1. After removing the barrel, remove the bolt handle
2. Pull the bolt assm out of the receiver as it sits on the bolt rail assm
3. Remove the link
4. punch out the two trigger assm pins and pull the trigger assm out of the receiver

To re-assemble;
1. slide the bolt assembly (sitting on the bolt rail) back into the receiver.
2. Install the bolt handle
3. Install the link; (I use a pair of needle nose pliers to hold the link while pushing back with a screwdriver the spring loaded interface. At this point the bolt assembly should slide freely back and forth, but not lock
4. Holding the receiver in my left hand, pull back the bolt assm all the way back and hold in place with your thumb(I believe I told you halfway). Now install the trigger assembly, and as Ulysses said, depress the shell latch button so the carrier clears.
5. Visually make sure your your trigger assembly pin holes are aligned, so you can tap the pins in. They should go in very easy, or repeat until you see no interference.
At this point, your gun is reassembled and the bolt should lock back in place. This took me about 10-15 minutes, but I've done it dozens of times.
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Discussion Starter · #12 ·
Happy Thanksgiving Pumped. Thank you for the photos. Your method of dropping the trigger group then putting the link in from the bottom certainly seems to be much easier than the way I do it - from the front of the receiver with the barrel off. I then slide the bolt assembly into place with the link sort of balanced in place. It usual takes several tries.

That begs a question. I make sure the two "wings" on the front of the link rest on the the action bar grooves on either side of the receiver. This means when the action cycles the wings slide back and forth in the groves along with the action bar.

Is this where they are supposed to be? Maybe that is part of my problem. Begs a second question. If the link wings do indeed ride/slide in the action bar groove, how do you get them in the groove from the bottom of the receiver? I've always found the only way to get them in (due to clearance) is to slide the link straight in from the front of the receiver when the barrel is off.
 

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Happy Thanksgiving Zanardi and everyone! I install the link after the bolt assembly is in the receiver. You can do so by holding the link perpendicular and toward the buttstock end of the receiver. It will slide into the slots, just as it came out. Here's a pic of how it should look installed
Wood Air gun Shotgun Gadget Trigger
 

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Discussion Starter · #14 ·
Thank you yet again pumped. I believe I have my link installed correctly based on your description and photos.

Unrelated - when I took my recoil spring and parts out to clean them up - the action spring follower (the piece that goes into the end of the recoil spring toward the receiver) on mine looks like the attached photo. Its long and tapered on one end and short and flat on the other. I didn't pay attention to how it came out. When I put everything back together I put the part in so the long tapered end went in first toward the receiver. The end of the spring then engaged with the short flat end.

I'm not sure if it makes a difference but it seems parts are designed the way they are for a reason. Any idea if I have this part installed the correct direction? I'm not convinced this has anything at all to do with the bolt not locking back but I should probably have it in the correct way regardless. The part looks different in all of the schematics so I have nothing to reference.

For what it's worth too I looked at my old Beretta AL2 and the end of the flat bolt release bar on it terminates right in front of the trigger assembly casting as well - the same as my SKB. Based on that I'm guessing that bar is as it should be on my SKB and is not the reason the bolt is not staying locked back.

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Thank you yet again pumped. I believe I have my link installed correctly based on your description and photos.

Unrelated - when I took my recoil spring and parts out to clean them up - the action spring follower (the piece that goes into the end of the recoil spring toward the receiver) on mine looks like the attached photo. Its long and tapered on one end and short and flat on the other. I didn't pay attention to how it came out. When I put everything back together I put the part in so the long tapered end went in first toward the receiver. The end of the spring then engaged with the short flat end.

I'm not sure if it makes a difference but it seems parts are designed the way they are for a reason. Any idea if I have this part installed the correct direction? I'm not convinced this has anything at all to do with the bolt not locking back but I should probably have it in the correct way regardless. The part looks different in all of the schematics so I have nothing to reference.

For what it's worth too I looked at my old Beretta AL2 and the end of the flat bolt release bar on it terminates right in front of the trigger assembly casting as well - the same as my SKB. Based on that I'm guessing that bar is as it should be on my SKB and is not the reason the bolt is not staying locked back.

View attachment 39501
I'm thinking that part would go in the other way, i.e. with the long tapered end going back into the recoil spring and the flat end facing the connecting rod. Is either end of this piece "cupped"? If so, that would be the end to face forward (toward the connecting rod).
 

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Look closely at the last pic I posted, along with the pic that shows the link outside of the upside down receiver. You can see the "ball" end of the link fits inside the part you referenced. From the pics it looks like the long end of that part goes into the receiver.
 

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Discussion Starter · #18 ·
Thanks guys. I did check out the schematic on the SKB website. The silver part I included a photo of looks different than the part pictured in the schematic which is why it wasn't of much use.

The silver part in my photo/gun is not cupped on either end. There is a cupped part visible in my receiver into which the end of my connecting link/rod fits. That did not come out when I took out my recoil spring and I did not attempt to push it out.

It appears I have two pieces on the receiver end of my spring. The silver part in my photo engages with the spring on one end and another cupped part that extends into my receiver and holds the end of the link rod. The schematic appears to show a single piece with a cupped end.

There may be different production versions out there. My gun is factory threaded for screw in chokes which seems unusual and hard to find (at least in my experience) for this model. I'm guessing mine is a very late production model before they were discontinued (probably back in the early 90's?). Maybe the parts were changed up at some point along the way for who knows what reason.
 

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I have both styles, fixed choke and choke tubes. I have never removed the action spring on these guns, so I can't speak to it. If the action spring follower is compressing properly, it would seem you have reassembled it right.......still worth investigating;
My biggest discovery getting the bolt to lock back is back to what I originally posted; it was two days of on and off trial and error until it finally worked. The guys at SKB confirmed they get calls from gunsmiths, etc., trying to get these guns back together. .I hope you get it back together properly; two trips to SD late season last year, and these guns performed flawlessly.....................and yes, you have to depress the shell latch button to load shells in the magazine tube on all the models I"ve seen. Keep us posted
 

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If you have to press the shell latch button to load shells into the magazine (like the Remington 1100), then it's likely that the shell coming out of the magazine hits the carrier release button which lifts the round up to be chambered (like the Rem 1100).

The lifting up of the carrier then releases the bolt to come forward to chamber the round. So, it would appear that whatever "thingamajigger" the carrier trips to release the bolt is stuck in the "release" mode.

What you need to do is find out what this "thingamajigger" is that is tripped by the carrier to release the bolt and figure out WHY it's stuck in the "release" position. It could be that a part is missing, or perhaps installed incorrectly, or that a piece/part is stuck in a certain position and not moving back and forth as it should. It's kind of like a valve that is stuck in the "open" position. You need to find out why it's not moving.
 
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