Jump to content
SASS Wire Forum

IAC CB Model 97 jamming


Recommended Posts

In an earlier thread, I mentioned that I was having problems with my new IAC Cowboy Model 97 failing to go into battery and locking up.


Yes, I am well aware that the action needs to be manipulated strongly and I tried a variety of different ammo, none of which made any difference. At home I used some dummy shells to try to identify where the actual problem was occurring. It never locked up when the shell was fed from the magazine, only when the shell was loaded into the ejection port so that the extractor had to ride over the rim of the shell base. :huh:


Aha! I was getting somewhere! I finally figured out that there were actually two interrelated problems. First of all, the right extractor was binding when trying to ride over the shell rim. This caused the bolt to fail to move forward far enough so that the locking lug on the riser could mate with the locking lug on the bolt. This was aggravated by the simple fact that the leading edge of both locking lugs was quite sharp and, with the very tight tolerance there, the lugs would not clear. The result was a nasty jam that was quite hard to clear. What to do?


With a fine file, I slightly rounded off the leading (sharp) edges of both the bolt and riser locking lugs to give them a bit more leading edge tolerance. However, I still got jams. It had to be something to do with the right extractor!


I found that the leading edge of the right extractor was rather rough and there were some small burrs on one side. Careful use of a fine file was used to smooth the leading edge of the extractor and remove the burrs from its sides. I then oiled and exercised the extractor spring.


Running some dummy rounds through the ejection port was successful. No jams! Then I carefully did the same thing with some different makes of live ammo. (Yeah, I was nervous doing that but took great pains to make sure that the gun could not accidently fire.) That, too, worked! The next step was to go to the range and do some live firing.


Today, I ran 25 rounds through the gun by loading into the ejection port and a friend also sent 25 rounds through the gun the same way. It worked smoothly and beautifully! No problems of any kind even though the weather was barely above freezing.


I do believe that I shall declare success! :)


[in case the thought should occur to any of you, I do plan to repeat the test in warm weather, too, but that will have to wait a while.]


Has anyone else had this particular problem? If so, what did you do and what were the results?




Link to comment
Share on other sites

A Big Congratulations on solving a big problem with the IAC 97s! I had the same problem with mine even though it was supposed to have been worked over by Coyote Cap. I wasn't sure what to do about it so I gave it to Shotgun Boogie and he went through it smoothed everything out as you said. I haven't had a problem with it since. Happy shooting, W. L.

Link to comment
Share on other sites

Will Lynchem,


Would you be so kind as to post the last three serial numbers of the your CB-97 and also the serial number of the upgrade action work, so I can determine which Cowboy Dealer your IAC

M-97cb was delivered to.


The most important serial numbers should be those located on the left bolt rail right behind the pin that secures the firing pin into the bolt.


The upgrade action serial numbers should be somewhere around the 3,800 area.


Those numbers are important to ascertain if your gun has received the new .200 mainspring, a new lightened "Chinese Titanium" firing pin and return spring and also two new inventions called the "Double Cocker" carrier timing change.


That information would be very helpful!


Thanks, - - - "Coyote Cap"

Link to comment
Share on other sites

Hi Cap:


Would you be so kind as to explain what this M-97cb "Double Cocker" modification looks like and/or how it works. I never heard of it and am quite curious.


BTW, tries to send you a message but was told that you could not receive any. It didn't say why you couldn't.




Link to comment
Share on other sites



I don't have a clue as to why messages are not coming through - I will investigate - thanks for the "heads up" about it .


To answer your question about the "Double Cocker" and carrier timing invention.


It is a .030 machined bump on the forward portion of the underside of the bolt, causing the hammer to be cocked twice, but also allows for a free floating return forward of the bolt into lock.


Sear length is critical to how the system works and almost all of the CB-97's have a sear length of .905, as compared to a Win. (Average) at .850


The free floating bolt gives those CB-97's such a smooth action, by eliminating the underside drag of the hammer on the bolt caused by the sear being a LOT longer and also closer tolerances caused by CNC machining of the frame, bolt, hammer, sear and carrier.


The "Double Cocker" bump has to be in exact position on the bolt, or the sudden pressure of the hammer being cocked the second time, can upset the carrier timing, which upsets the ejection.


This problem is found in later production IAC M-97w-20cb models with serial numbers above 450 and the cure is not simple and requires welding twin ramps to the carrier, to force the carrier back down before the bolt can reach the ejector.


How you can tell if your new CB-97 has this problem is to see how far the ejected hulls clear the breech upon ejection. If only a few inches, take out the carrier and try the extracting and ejecting process without the carrier installed.


I will bet the extracted/ejected hull will now fly a good 8 to 10 feet across the room.


The cause is the "Double Cocker" to carrier timing has been messed up at the factory, probably by installing an older bolt in a CNC'd gun.


Also, as part of the system is the close tolerances provided by CNC machining which decreases the wear factor involved with high speed cycling.


When all is correct, the CB is VERY STRONG at ejection and SUPER SMOOTH in cycling.


It took me (4) trips to China over 17 years to get these Cowboy Competition M-97's built to the same (but improved) specifications associated with the outstanding M-93/97 of five years ago.


There are very few gunsmiths that are aware of how these new CB-97's work or how to correct a problem with a "Double Cocker" system they never heard of, except to get lucky by smoothing a few parts and then take credit for fixing it.


I hope I haven't messed with your mind in this long winded explanation to the problem that was the original question in this posting!


"Coyote Cap"

Link to comment
Share on other sites

Hey Cap, I tried to PM you with the info you wanted along with where and when it was purchased and a summary of what went wrong and what fixed it. I love this shotgun now and am looking forward to purchasing another one in a couple of months.

It was a lengthy PM so do you want me to post it here or email it to you, Will.

Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.