Iver Johnson Thread

[Varminterror]

Taking a long shot here, and it’s largely irrelevant now, but would anyone happen to know the thread pitch for an Iver Johnson Champion stock bolt? Is it really 1/4-24?

I measured the major diameter at .2450” and 24 tpi with a pitch gauge. But I’m surprised to see 1/4”-24. I also ran it through some reference nuts to confirm the gauge, since the threads are old, worn, and relatively irregular - it’s NOT 1/4-20 nor 1/4-28, nor is it M6 or M7. Just an odd size 1/4-24, wondering if that changed during their production, or if these were simply old enough to predate standardization for course and fine thread pitch.

I’ve cut down a stock for my grandpa’s old Champion 410 (4th Generation in my son’s hands), naturally leaving the bolt too long. 1/4-24 dies are out there, but the thread stands proud from the shank, such the shank is smaller than the major diameter of the thread, so I decided to work on the head end instead of extending the threads. I’m cutting the head end shorter, threading 1/4”-20 for a short length, screwing on a nut, and welding in place. I MAY cut a groove as a screwdriver compliance, but otherwise plan to remove the bolt in the future with a socket. I bought a replacement bolt and replacement stock - two actually, since grandpa and dad had damaged the original beyond repair. When he gets old enough for a full length, I’ll simply put the other new stock and the original stock bolt back on it.

 

[beag_nut]

That's an interesting situation. I don't happen to know what the pitch is, but I could tell in about a minute with my thread pitch gauges, if I had the screw here. Those gauges don't cost much and are very handy. If I recall correctly, you do a lot of gun work and that could justify such a purchase. I do like your present solution to the problem.

 

[Varminterror]

Thanks @beag_nut - sorry, my original above isn’t clear. Pitch gauges are how I measured the 24tpi. I also ran through a handful of reference nuts to confirm it’s NOT the other, more standard options. Edited to reflect. The bolt is old and worn, naturally, so the threads appear a bit irregular (and ARE irregular for major dia), but it threads cleanly and freely into the receiver. So I measured AND validated my measurement.

I’m more surprised to see an oddball thread used. And maybe a little frustrated to see the threads proud to the shank, rather than cut into, as it does force a more involved and less elegant solution. Wholly functional, but less desirable.

 

[BBBBill]

It's a gun so, when it comes to screws, all bets are off.

 

[BBBBill]

Delete.

 

[Obturation]

When I run across an odd thread ,if the bolt Is able to be recreated I'll just drill and tap the hole slightly larger and use a normal and available fastener. Not sure that's a solution for you in this case though.

 

[beag_nut]

If some are surprised with "odd" threads, they should look at some Starrett instruments to see how really odd things can get. Being a former machinist I can tell you that they (perhaps) deliberately used strange thread combinations in many of their tools/ instruments. I suspect it is to try to prevent copying. I have a set of parallel clamps with a broken screw, and cannot find a replacement anywhere, INCLUDING Starrett.

 

[Varminterror]

@Obturation - I COULD ream and retap the receiver, I’m confident there’s enough meat on the receiver to do so, but putting a new head on a bolt would be less risk, and should be easier.

I took this photo for another purpose of another gun part this week, but the IJ was on the bench. I cropped down, but this is the receiver spindle which mates with the stock bolt, at top left. Retapping or not, I have to cut a custom length bolt anyway, so putting a new head on a $20 take-off bolt with no risk to the receiver instead of retapping AND making a bolt is an easy choice.



She’s ugly, but she’s ours. My grandpa, my dad, and I have ported this little shotgun after bunnies with little regard for her health, and now my son is old enough to do so as well. My entire life (until now) the stock was broken (held together with an exhaust clamp at the grip neck when I got it), she was rusted, the hammer spur broken off, and the forend snap plate missing, so I hunted it all of my life without a forend. It always worked - even has a rather decent trigger, but in the 30yrs I have had it myself, it certainly has been on the verge of “unusable.” As maybe a bit more than a hobby smith, I don’t have any excuse to give it to my son in this condition. She’s still rusty, but I replaced the hammer, fabbed a new hammer pin to replace the bent original, bought a new snap plate assy from Numrich, bought another as a parts gun (chambered for 44cal shotshell, 44-40 shotshells, such it’s largely unusable anyway) to get good condition forend and stock, and bought a duplicated stock to cut down to his current 11” LOP (10.25” currently, but will grow fast, assuredly) - also replacing the line checkered plate which came with the repop stock with a repop IJ owl buttplate, trimmed to fit the new, smaller buttstock footprint source on eBay. I may send all of the metalwork out this summer to be reblued, but I’ve discussed with a few resto-smiths that I will likely lose the markings, since the original stampings (save the serial) are very shallow. I may hand chase the text before bluing, but I’ve debated conceding to let the makers marks disappear, and paying a more skilled scratch than myself to engrave new markings with a more pleasant aesthetic. Or maybe my boy will simply want to shoot it as it is, patina and all.

 

[12Bravo20]

Actually 1/4" 24 is a common thread size for machine screws. Here is just one example: https://www.lowes.com/pd/Hillman-1-...bination-Drive-Machine-Screws-5-Count/3035893. You might get lucky and find one the correct length that you need.

Savage is another one that uses an oddball size bolt. The stock bolts on the MkII and 93 series rifles is #12 - 32 instead of the more common #10 24 or 1/4" 28