Cracked Choke Tube

O'Shark

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Mar 2, 2011
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Ladoga, IN
This is out of a second hand, 35 year old Mossberg model 500. I had trouble getting the tube out so I soaked it overnight. This was my "pheasant" shotgun and slugs were never fired since it also has a slug barrel. The tube finally came out and this is what I found:
 

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worddoer

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Jul 25, 2011
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Did you pull the gun apart and inspect it when you bought it? If so, did you use some grease or Never-Ceez to lubricate it prior to installation? I like to use some high temp bearing grease on mine. Maybe some rust formed between the choke and the barrel, it put enough pressure on it to fracture it? Is there any other damage to the choke inside or outside?

I ask because I have had 2 relatives who had their chokes rusted in place and both came to me thinking I could easily fix it.

They did not take care of their guns (I am assuming they got wet during hunting). Even those who clean and oil their shotguns regularly after a hunt can forget to pull the choke to clean and lube the threads (which I only do if copious amounts of water were involved).

On the guns brought to me, the chokes were basically rusted in place. A week long endeavor using a combination of a heat gun (I had to be careful due to plastic front bead) and LOTS penetrating oil eventually got them out.

It took a bit to clean the threads of the barrels though. I happened to have a really stiff plastic bristle cleaning brush that I chucked into my drill and ran the same direction as the threads. More penetrating oil and some high speed cleaning and thankfully the threads in the barrels cleaned up nicely.

I had them both buy new chokes (I was thinking they ran less than $20 each) and when I installed them, I use the same process as mine...high temp bearing grease. It holds up a bit better to a hot/warm barrel...it tends to be more water resistant than most gun oil...and it stays in place and will not leach out.

My father (who was a auto mechanic for several years) likes to use Never-Ceez. He has not had problems, but he does not tend to get his guns in wet / adverse climates either. So not sure if that is better or not.

Not sure why the choke cracked, but seems to me that a really good inspection with a magnifying glass should be done of the end of the barrel and it's threads to make sure it does not have damage. Better to buy a new barrel than to have something blow up and hurt yourself or someone nearby.
 

O'Shark

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Ladoga, IN
You guys brought up some good points. I have shot steel shells on a goose hunt but less than a dozen. I will get the bright light and magnifier out and look at the last few inches of the barrel. That one choke tube has been difficult to remove almost from day one. I haven't noticed any trouble with the other two tubes. I bought it at used at a gun shop in Muncie and have taken several birds with it over the years.

I have hunted in sleet and snow but I'm diligent about keeping my guns clean. I removed the long, ribbed barrel years ago and installed the shorter slug barrel. I saw the ribbed barrel sitting there and decided to see if I could remove that choke tube since I had so much trouble with it in the past. It was totally stuck. I put the muzzle end down into a plastic bag and sprayed some Ballistol into the chamber and let it run down into the threads and waited a day. That did the trick. There was a little rust on the threads which came off easily with a bronze brush.

An internet search showed several posts in various forums about cracked choke tubes in various brands of shotguns. The metal seems thin on the tube. I honestly wonder if I didn't crack it just by removing it. If it was the rust that had it stuck in one spot, I can see how the wrench could pull the tube apart but it's hard to believe I put that much torque on it. The barrel was off the gun so I had to hold it in one hand and turn the wrench with the other. I will definitely use anti-seize in both that barrel and in my Model 37 from now on too.

I thought it was interesting that it cracked but I'd like to know why! The first order of the day will be to inspect the end of that barrel.

Thanks for the suggestions.
 

Tombs

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This may be a shot in the dark here... But I wouldn't be surprised if it cracked when being removed. If it was really brittle hardened steel, that wouldn't surprise me at all as thin as most chokes are. Could have been an overly brittle heat treat.

I find the concept of a slug or steel shot cracking a STEEL choke to be a bit hard to fathom.
 

O'Shark

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Mar 2, 2011
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Ladoga, IN
Well, I inspected the muzzle end using a 10X magnifier and a light. There were no cracks and the threads are fine. I sent an email off to Mossberg to see if they can give me a date of manufacture. I also sent them the picture just as a data point for their quality dept. I'll report back if they have any idea why this would've happened.
 

Tombs

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Jan 13, 2011
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Well, I inspected the muzzle end using a 10X magnifier and a light. There were no cracks and the threads are fine. I sent an email off to Mossberg to see if they can give me a date of manufacture. I also sent them the picture just as a data point for their quality dept. I'll report back if they have any idea why this would've happened.
If it was old crack, there likely would have been a visible line around the recess in the barrel for the choke. So that kinda proves the theory that it cracked on removal.
 

Leadeye

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Jan 19, 2009
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This may be a shot in the dark here... But I wouldn't be surprised if it cracked when being removed. If it was really brittle hardened steel, that wouldn't surprise me at all as thin as most chokes are. Could have been an overly brittle heat treat.

I find the concept of a slug or steel shot cracking a STEEL choke to be a bit hard to fathom.
I've picked up some doubles cheap and cut them down that had bulges from steel shot. Granted they were from the 70s.
 
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