Dred Bob Posted June 24 Posted June 24 (edited) I purchased a well used 66' Yellowboy (Cimmaron Navy Arms .38 Spc, 1st gen?) from another cowboy. Smoothest feeling action I've ever encountered and looks beautiful BUT it only fires about half the cartridges I run through it. Primers are showing light strikes. I pulled it apart and thoroughly cleaned the firing pin and bolt and still isn't firing. The trigger spring feels very heavy and maxed out so I don't think that's the issue. I purchased a replacement Slix Firing Pin from Longhunter. It comes oversized (I guess) and needs to be fitted. The original pin I pulled is 1.935". The new pin is 1.970". I installed the new pin and it noticeably sticks out from the bolt face and cycling a cartridge leaves an imprint on the primer and the round hangs up some on extraction. I noticed some other differences in dimensions on the base end of the pin as well. Before I started filing things down I thought I'd check here to see what I should be looking for to determine what to modify and how much. My first thought is to just take 0.010" off the end and check it again. Since whatever I take off I can't put back I wanted to get instruction from those that know. Edited June 24 by Dred Bob discovered it's a Navy Arms 1 Quote
PaleWolf Brunelle, #2495L Posted June 24 Posted June 24 https://www.slixprings.com/proddetail.php?prod=SliXprings-Firing-Pin Installation Instructions 3 2 Quote
The Original Lumpy Gritz Posted June 24 Posted June 24 Have you tried with factory ammo? You should..... Try a new hammer spring. 2 Quote
Sedalia Dave Posted June 24 Posted June 24 How much play does the firing pin extension have? Over time the hole in the frame will wear and this allows the firing pin extension to bind up when the hammer strikes it. I had a 66 that this happened to. Sent it off to Snake Oil George and he trued up the hole in the frame and installed an oversized firing pin extension with a one piece firing pin. He also made a few other mods to the action. When it came back it felt like a different gun. 1 1 Quote
Griff Posted June 24 Posted June 24 As an aside, I might be wrong, but... Cimmaron didn't import any of what I consider the 1st Gen 1866's... I think those were only available in .38 Spl. I don't know if they were the same size (dimensionally) as the 44 Henry Flat only available from Navy Arms, but I believe those 38 Spl versions were also imported by Dixie Gun Works and EMF. By the time Cimmaron opened, (mid-1980s), the Uberti '66 had been upsized to have the same carrier mortise as the '73. Quote
Dred Bob Posted June 24 Author Posted June 24 (edited) 5 hours ago, The Original Lumpy Gritz said: Have you tried with factory ammo? You should..... Try a new hammer spring. honestly, I don't have and haven't bought factory .38 in over a decade. The hammer is pretty heavy so I don't think that's the issue. I have the new pin I just have to *fit* it first. If that doesn't work I might be able to scavange a hammer spring from a 73' although I don't actually know that they're the same. Edited June 24 by Dred Bob Quote
Dred Bob Posted June 24 Author Posted June 24 (edited) 2 hours ago, Griff said: As an aside, I might be wrong, but... Cimmaron didn't import any of what I consider the 1st Gen 1866's... I think those were only available in .38 Spl. I don't know if they were the same size (dimensionally) as the 44 Henry Flat only available from Navy Arms, but I believe those 38 Spl versions were also imported by Dixie Gun Works and EMF. By the time Cimmaron opened, (mid-1980s), the Uberti '66 had been upsized to have the same carrier mortise as the '73. I provided some misinformation. I went by memory and thought the rifle is a Cimmaron but the barrel is marked "Navy Arms Co Ridgefield NJ -> Italy" and the receiver tang marked "Caliber 38 Special". So it might not be compatible with other 66 parts / 73? Edited June 24 by Dred Bob Quote
Dred Bob Posted June 24 Author Posted June 24 2 hours ago, Sedalia Dave said: How much play does the firing pin extension have? Over time the hole in the frame will wear and this allows the firing pin extension to bind up when the hammer strikes it. I had a 66 that this happened to. Sent it off to Snake Oil George and he trued up the hole in the frame and installed an oversized firing pin extension with a one piece firing pin. He also made a few other mods to the action. When it came back it felt like a different gun. it was originally fouled up with grease but after cleaning the pin moved freely in the bolt. It doesn't feel like it is binding or anything after assembly. It just doesn't punch deep enough for ignition reliably. Quote
The Original Lumpy Gritz Posted June 24 Posted June 24 29 minutes ago, Dred Bob said: honestly, I don't have and haven't bought factory .38 in over a decade. The hammer is pretty heavy so I don't think that's the issue. I have the new pin I just have to *fit* it first. If that doesn't work I might be able to scavange a hammer spring from a 73' although I don't actually know that they're the same. Using factory removes all questions if it could be your reloads. Quote
The Original Lumpy Gritz Posted June 24 Posted June 24 11 minutes ago, Dred Bob said: it was originally fouled up with grease but after cleaning the pin moved freely in the bolt. It doesn't feel like it is binding or anything after assembly. It just doesn't punch deep enough for ignition reliably. Measure how much the pin sticks out from the boltface. Quote
Colorado Coffinmaker Posted June 24 Posted June 24 (edited) I sounds to me like you actually have one of "The Ancient Ones." I would have to compare dimensions of the Breach Block (bolt) and the Carrier Block to be sure. If the rifle is one of the really really OLD '66s, new build Uberti and after-market parts aren't comparable (compatible, Otto, compatible) for the most part. Everything may well require extensive fitting. If you have a more recent build Uberti Toggle Link rifle, you need to measure the Carrier Block and the Carrier Block Mortice in the frame. The Old Bolts and Carrier Blocks are shorter than newer Uberti guns. The Firing Pin needs to retract fully into the Bolt with no pressure from the Extension Rod. Without hands-on, I am not able to tell exactly which end (if not both) needs fitting. The firing pin also needs reshaping the contact end of the firing pin to be more pointy. Edited June 24 by Colorado Coffinmaker fix it and I hate OTTO 1 Quote
Griff Posted June 24 Posted June 24 46 minutes ago, Dred Bob said: I provided some misinformation. I went by memory and thought the rifle is a Cimmaron but the barrel is marked "Navy Arms Co Ridgefield NJ -> Italy" and the receiver tang marked "Caliber 38 Special". So it might not be compatible with other 66 parts / 73? Measure the carrier mortise, if it's shorter than 1.600" It likely is one of those 1st gen '66s. Measure the bolt length also, that might give you an idea of the correct firing pin lenght. Quote
Sedalia Dave Posted June 25 Posted June 25 8 hours ago, Dred Bob said: it was originally fouled up with grease but after cleaning the pin moved freely in the bolt. It doesn't feel like it is binding or anything after assembly. It just doesn't punch deep enough for ignition reliably. How much up and down / side to side movement does the FP extension have in relationship to the frame? The FP extension is what pushes the firing pin installed in the bolt. If the hole in the frame is worn the FP extension will move out of proper alignment when the hammer strikes it and cause the bolt, firing pin, firing pin extension assembly to bind. This will cause the light strikes you are seeing. With the assembly out of the gun, hold the bolt while pressing in on the firing pin extension. How far does the firing pin protrude past the bolt face? Quote
Dred Bob Posted June 25 Author Posted June 25 16 hours ago, Colorado Coffinmaker said: I sounds to me like you actually have one of "The Ancient Ones." I would have to compare dimensions of the Breach Block (bolt) and the Carrier Block to be sure. If the rifle is one of the really really OLD '66s, new build Uberti and after-market parts aren't comparable (compatible, Otto, compatible) for the most part. Everything may well require extensive fitting. If you have a more recent build Uberti Toggle Link rifle, you need to measure the Carrier Block and the Carrier Block Mortice in the frame. The Old Bolts and Carrier Blocks are shorter than newer Uberti guns. The Firing Pin needs to retract fully into the Bolt with no pressure from the Extension Rod. Without hands-on, I am not able to tell exactly which end (if not both) needs fitting. The firing pin also needs reshaping the contact end of the firing pin to be more pointy. Measurements 1.960" : New Pin 1.930" : Old Pin 1.508" : Carrier Length 1.515" : Carrier (Mortice?) 1.437" : Bolt 5.160" : Bolt + Ext open 5.130" : Bolt + Ext compressed 0.025" : pin extended beyond bolt face (open) 0.060" : pin extended beyond bolt face (compressed) 0.030" - 0.035" : current pin travel even though the pin is extended beyond the bolt face it is not leaving a noticeable dent in primers unfired but I haven't cycled a full mag through it. Just tested a couple quick cartridges. I have taken 0.010" off the new pin to start fitting. I probably should have taken it off the base first. I can't safely test fire the rifle where I live. Quote
Dred Bob Posted June 25 Author Posted June 25 16 hours ago, Griff said: Measure the carrier mortise, if it's shorter than 1.600" It likely is one of those 1st gen '66s. Measure the bolt length also, that might give you an idea of the correct firing pin lenght. 1.515" ...... {see my full response in the thread for all measurements" Quote
Griff Posted June 25 Posted June 25 1 hour ago, Dred Bob said: I have taken 0.010" off the new pin to start fitting. I probably should have taken it off the base first. I can't safely test fire the rifle where I live. Mind ya, I ain't a gun mechanic, but, I think, yeah, the base end would be a good place to start. To test... just use a primed case. Ya don't need all that pesky powder & projectile stuff. 3 Quote
Dred Bob Posted June 25 Author Posted June 25 did some more playing around. I did notice that the punch I was using to act as the pin between the bolt and extension had a slight bend from abuse that was skewing the #'s a bit for FP travel. I used the actual pin and 0.005" - 0.060" : new firing pin extension from bolt face 0.000" - 0.040" : original firing pin extension from bolt face I checked to see if I could just file down the inside collar of the origin pin base to get more extension but the issue is that the extension is fully blocked by the bolt. I'd have to remove material from the inside of the bolt or add material the original pin base to get more extension. What I have is probably as good as i can get with the new bolt since I removed 0.010" off the pin instead of the base. I need to probably test this and see if I get ignition and it can cycle. If not I'll have to buy another pin and remove from the pin base. So far I've learned you have to potentially fit the pin at 3 locations. Base, inside collar, and tip. Maybe the 0.015"-0.020" I gained so far will fix the problem without creating any new ones. Quote
Colorado Coffinmaker Posted June 25 Posted June 25 PLUS ONE for Sedalia Dave. .040 firing pin extension beyond the bolt face should be more than sufficient. You DO NOT want to remove anything from the base of the replacement extended firing pin. You should only remove enough from the front of a new firing pin to result in the pin retracting inside the bolt face. Optimum Head Space is .004 and anything over .008 is flirting with fail to fire. If the Head Space is bad, you have a real problem as there are no parts available for "The Ancient Ones." Although there may be a "sort of" fix, depending on the actual head space. Yule need a set of tapered automotive feeler gauges to check between the the cartridge head and Breach Block face when fully chambered. Quote
Abilene, SASS # 27489 Posted June 25 Posted June 25 One other possibility, If the gun was ever fired out of battery it could have bent the lifter arm and that will affect headspace. With the side plate off, see if the toggles line up straight when the bolt is forward. 1 Quote
Dred Bob Posted June 25 Author Posted June 25 2 hours ago, Sedalia Dave said: What is the headspace? I don't know how to check that. I don't have any feeler guages but I'm sure amazon has something so it might take me a while to check it 2 hours ago, Colorado Coffinmaker said: PLUS ONE for Sedalia Dave. .040 firing pin extension beyond the bolt face should be more than sufficient. You DO NOT want to remove anything from the base of the replacement extended firing pin. You should only remove enough from the front of a new firing pin to result in the pin retracting inside the bolt face. Optimum Head Space is .004 and anything over .008 is flirting with fail to fire. If the Head Space is bad, you have a real problem as there are no parts available for "The Ancient Ones." Although there may be a "sort of" fix, depending on the actual head space. Yule need a set of tapered automotive feeler gauges to check between the the cartridge head and Breach Block face when fully chambered. I'll pick up some guages and give this a check. thank you for some reference #'s 1 hour ago, Abilene, SASS # 27489 said: One other possibility, If the gun was ever fired out of battery it could have bent the lifter arm and that will affect headspace. With the side plate off, see if the toggles line up straight when the bolt is forward. I don't see any damage or strange wear. the linkages and everything operate extremely well and smooth. I honestly don't see much wear or signs of customization. Quote
Colorado Coffinmaker Posted June 25 Posted June 25 OK. Visit your local Auto Parts Emporium. You're looking for "tapered" blade type feeler gauges. The tapered blades are fit between the cartridge base and the face of the Bolt without hitting against the side of the mortice. You should be able to "just" close the action on an .004 gauge. If you are able to fit an .008 or more blade, you have a head space problem. Quote
Garrison Joe, SASS #60708 Posted June 26 Posted June 26 7 hours ago, Abilene, SASS # 27489 said: If the gun was ever fired out of battery it could have bent the lifter arm and that will affect headspace. Not the lifter arm. That will not affect headspace, since it does contact the the toggle links in any way. BUT - a bent lever can certainly affect the headspace. An OOB discharge can bend the lever to open up additional headspace. That is why after an OOB, it is important to check headspace and complete straight-line alignment of the links at action lock-up. good luck, GJ 2 Quote
Abilene, SASS # 27489 Posted June 26 Posted June 26 1 hour ago, Garrison Joe, SASS #60708 said: Not the lifter arm. That will not affect headspace, since it does contact the the toggle links in any way. BUT - a bent lever can certainly affect the headspace. An OOB discharge can bend the lever to open up additional headspace. That is why after an OOB, it is important to check headspace and complete straight-line alignment of the links at action lock-up. good luck, GJ Thank you for the correction GJ, I MEANT lever! Once when talking to Jim Bowie about longer links for a headspace issue with a 32-20 '73, he told me to bend the lever first, saying that many Uberti rifles have headspace issues out of the box and bending the lever usually corrects it. Didn't fix mine though so he sent me the longer links. 2 Quote
Dred Bob Posted June 26 Author Posted June 26 9 hours ago, Abilene, SASS # 27489 said: Thank you for the correction GJ, I MEANT lever! Once when talking to Jim Bowie about longer links for a headspace issue with a 32-20 '73, he told me to bend the lever first, saying that many Uberti rifles have headspace issues out of the box and bending the lever usually corrects it. Didn't fix mine though so he sent me the longer links. so while I wait for gauges. I didn't know that links came in different lengths? do you have them customized? custom made? For now I'm just curious but if my headspace needs to be adjusted it would be worth knowing. That and it's just worth knowing With my luck since this appears to be an early model Navy Arms in .38spc only, that it's totally custom and the rifle becomes a wall hanger or parts gun, but I'm ahead of myself. Quote
Abilene, SASS # 27489 Posted June 26 Posted June 26 Hi Dred, yes some or all of the short stroke link makers have/had a set(s) with longer links for those with headspace issues. And yes, with the shorter action parts in your older gun, nobody makes anything to fit yours. To short stroke your gun would be a cut-and-weld operation, and you most likely don't want to make a race-gun out of an older gun with no parts available. 3 Quote
Dred Bob Posted June 29 Author Posted June 29 On 6/25/2026 at 3:18 PM, Colorado Coffinmaker said: OK. Visit your local Auto Parts Emporium. You're looking for "tapered" blade type feeler gauges. The tapered blades are fit between the cartridge base and the face of the Bolt without hitting against the side of the mortice. You should be able to "just" close the action on an .004 gauge. If you are able to fit an .008 or more blade, you have a head space problem. gauges came in. I was able the get a .011 between a spent brass and the bolt. I did run some rounds through the rifle with the new firing pin after I did my fitting. No dents on any primers for a full magazine but I didn't get to a range yet to see if they all go "boom". Quote
Dred Bob Posted June 29 Author Posted June 29 On 6/26/2026 at 10:27 AM, Abilene, SASS # 27489 said: Hi Dred, yes some or all of the short stroke link makers have/had a set(s) with longer links for those with headspace issues. And yes, with the shorter action parts in your older gun, nobody makes anything to fit yours. To short stroke your gun would be a cut-and-weld operation, and you most likely don't want to make a race-gun out of an older gun with no parts available. It is not currently short stroked and I'm not looking to turn it into a race gun. I just want it to work as intended and maybe run it in the occasional local match for fun. The 66's are a beautiful rifle. I hate having it and knowing it isn't working correctly and just hanging on a wall isn't where it belongs. I would be willing to send it off to somebody if I can't figure out how to get it running myself. I've learned a lot with this thread even if I can't make the repair. Worst case I'm planning on going down to KY for Black Gold in a couple of weeks and Lassiter has been known to show up there. Maybe I can get him to take it home and give it some love. 3 Quote
The Original Lumpy Gritz Posted June 29 Posted June 29 You definitely have a headspace issue that needs to be corrected before anything else is done. Quote
Colorado Coffinmaker Posted June 29 Posted June 29 PLUS ONE fer The Original Lumpy Gritz. There are NO parts available for your '66 so the only real good way to solve you head space problem is have the Barrel Set back which may also require it to be rechambered. Good Luck. Quote
Griff Posted June 29 Posted June 29 13 minutes ago, Colorado Coffinmaker said: PLUS ONE fer The Original Lumpy Gritz. There are NO parts available for your '66 so the only real good way to solve you head space problem is have the Barrel Set back which may also require it to be rechambered. Good Luck. Might not the bolt be modified? Quote
The Original Lumpy Gritz Posted June 29 Posted June 29 5 hours ago, Dred Bob said: It is not currently short stroked and I'm not looking to turn it into a race gun. I just want it to work as intended and maybe run it in the occasional local match for fun. The 66's are a beautiful rifle. I hate having it and knowing it isn't working correctly and just hanging on a wall isn't where it belongs. I would be willing to send it off to somebody if I can't figure out how to get it running myself. I've learned a lot with this thread even if I can't make the repair. Worst case I'm planning on going down to KY for Black Gold in a couple of weeks and Lassiter has been known to show up there. Maybe I can get him to take it home and give it some love. Best to call him and confirm!..... 1 Quote
Colorado Coffinmaker Posted June 30 Posted June 30 Griff 😊 Not really. Adding at least six thou to the bolt face requires welding up the bolt face, re-drilling the firing pin hole, machining the bolt face for head space, making a new cartridge guide tab, making or modifying(?) the extractor and finding/modifying a firing pin to fit. Way easier to set the barrel back about one turn (and cheaper) 1 Quote
Dred Bob Posted July 2 Author Posted July 2 called Lassiter, gonna meet up with him down at Black Gold and let him have a look. this was a really instructive thread and if nothing else I feel like I understand these rifles just a little better and less intimidated by taking it down and removing the bolt! 1 2 Quote
Rooster Ron Wayne Posted July 3 Posted July 3 I have owned a couple of the short carrier 66's by Navy Arms over the years . Everything you need will be a part you need to custom fit . Nothing I mean nothing is made today that is a drop in part . Rooster Quote
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