3/8x10 to 3/8x10 .308

Kim Bye

Kim Bye

AzB Silver Member
Silver Member
I got a few shafts with regular 3/8x10 threads. But the cues i use has the 3/8x10 .308 flat minor pin, making it next to impossible to use my shafts.
Can i buy a 3/8x10 .308 tap and re thread or "widen" the threads to fit my 3.308 flat pin or will that totally mess up the threads?
 
3/8x10 .308

Just took a pin with the .308 and screwed it into to a shaft that was tapped for the normal 3/8x10 and it fit fine. Are you sure the shaft is not the one with the minor and the pin is the standard thread
 
Kim Bye said:
I got a few shafts with regular 3/8x10 threads. But the cues i use has the 3/8x10 .308 flat minor pin, making it next to impossible to use my shafts.
Can i buy a 3/8x10 .308 tap and re thread or "widen" the threads to fit my 3.308 flat pin or will that totally mess up the threads?
Click to expand...

Kim,
Take your "regular" 3/8-10 shafts to a cue mechanic who is familiar with the difference. He/She will bore out the minor in the shaft for you. Then you can use that shaft on either type of butt pin.
My 2 cents,
Gary
 
I just ran into this problem last week. I swear I checked my .308 minor pins to make sure they fit into after market LD shafts and I sent out a cue only to find out that is doesn't fit. There was a variance in the pins from one batch to another and again in a different material. I'm changing that particular pin to the v-thread 3/8-10 to accommodate other shafts.

Now, if you have a shaft or two that you want to fit the butt with the .308 minor, boring the shaft a little isn't going to knock the earth of kilter.
 
I use the .308 flat pins in my cues. Regular 3/8 x 10 should work just fine on the .308 pin since the regular 3/8 x 10's are drilled with .312 or 5/16 bit it is 4 thou. bigger than .308.

My 3/8 x 10 tap and the .308 tap are the same except for the bullet nose on the .308 is .308 to help guide the tape in the .308 hole. Have no problems screwing either shaft either way.

If it is tight just put wax on the pin. If this does not work run 5/16 bit and 3/8 x 10 tap thru the hole to clean up as sometimes moisture will swell threads.

If these shafts have phenolic inserts then yes you will need to drill with 5/16 bit again and run the 3/8 x 10 tap in and out a few time to loosen and fit .308 flat.
 
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Rather than running a 5/16" drill bit into the hole I would suggest running a 5/16" reamer. The reamer will maintain the centering that existed before this mod, as opposed to a drill bit that doesn't care if it wanders off center a little bit.

TW
 
Hi,

McMaster Carr sells chucking reamers in any size in .0005 increments.

They are about 9 inches long and do self center well into the bored hole very nicely with no Walking.

When I do my shafts I drill my blind hole undersize of my minor, bore undersize of my minor just to establish concentricity, then let my chucking reamer follow in to a specific size. This way no test pin or measuring the hole and you hit the dimension every time.

My pin is non standard and not .308 or I would share the reamer size.

I had to buy a few reamers to get a nice firm thread engagement all the way in and out on my shaft inserts. Very repeatable!

Mechanical thread standards for fit up of nuts and bolts are too sloppy for joining a cue the way I see it. Adjusting the minor allows you to control the situation concerning the interference delta. When a tighter fitting joint faces, it locks up hard and you can't over torque the joint with just hand pressure and stress the threads IMO.

It is amazing the difference a half a thou makes concerning the fit when screwing on a shaft. I got it right on the third reamer.

Happy happy joy joy!!!

Rick
 
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The cues i got is from Jim Baxter and Leon Sly. The Baxter got a brass pin and the Sly has a aluminum pin.
other than the metal, they look very similar, but the brass pin actually makes the fit even harder.
i don`t know where Mr. Baxter and Mr. Sly get their pins from, but they do look like a standard Atlas 3/8x10 F pin.
I have to add that all the 3/8x10 shafts i have tried. Katana, Predator and McDermott all have a plastic insert og some kind. That may make it ekstra tight?
I`m gonna try really carefull with a 3/8x10 .308 tap and see if that makes a difference.
If that does not work i have to send my shafts to a professional...
I must say that it sucks BIG TIME that 3/8x10 has so many stupid variations, it`s a nightmare for the customers!
 
It is not the variation but the inserts. If they were wood you would not have this problem. Just get someone to run a 3/8 x 10 tap in and out a few time and it will fix the problem. I have to do this all the time for people with inserts in their shafts.

Most repair guys will do it for free as I do.
 
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