Short Barrel - Long Headstock

[rbertalotto]

The need to chamber a 13" barrel for an XP-100 arose.

I wanted the bore of the muzzle centered in the headstock, but it simply wasn't long enough to reach the spider.

I would rather not chamber in the steady rest, although that is how I've done short barrels in the past.

Instead I made up this device. the "delrin" plug was to not damage the crown as this barrel was being rechambered and the crown was complete.

Worked out great. The only way it would work better is if the headstock plug was a precision expanding mandrel..........

 

[TRECustom]

Roy B, I couldn't open the photo, but I have run into the same problem a couple of times with barrels that were shorter than my spindle. I ended up in the steadyrest with both of them, but had to make a steel rider ring with a teflon bushing to protect the high-polish blue on one of them. The Delrin plug would have been much quicker to make. I wonder how true it would be if I made an aluminum plug with a couple of O.D. grooves for o-rings that tight-fitted in the spindle bore, then center bored and threaded it for individual caliber threaded Delrin or hard teflon pilots? The plastic pilots could have a threaded base plug (3/4" dia ?), with a short shoulder. Might work if the pilots were screwed into the aluminum plug and then turned to caliber. Better chance of being concentric. Sounds like a project for a long rainy day, maybe.

Thanks for posting, Tom

 

[rbertalotto]

Hopefully you can see the image now........

 

[TRECustom]

Thanks Roy, as good or better than my scheme, and much simpler to make and use! I don't have Delrin, but do have some small pieces of filled (hard) teflon rod I can try.

I appreciate the dwg.

Tom

 

[DCRYDER]

Nice concept! I just wonder if instead of the "spindle plug" having a recessed cone and different pilots made for it, would if work just as good or even better if it was made with a 60* protruding cone. This would be a 1-piece, and universal "pilot" that could be used for any caliber, seems to me it may be a stronger setup, and definately faster and easier to make.

 

[TRECustom]

DC, I thought about the cone. Most of the time it would work, but a lot of short barrels have front sights. Many of them can go inside the spindle and center up without taking the base off, and some have bases that are shrink-fitted or hard-soldered on. Those would interfere with a nice deep cone. In those cases, it would be quicker to use the bore instead of the O.D. of the muzzle. On the rest, the cone would be easier to make and faster to use.

Roy, I'm going to see if I can find a piece of Delrin stock. None of my Teflon rod is big enough, and I've got to buy something anyway. Aluminum would work, but a good snug fit would make it hard to push out of my spindle. The I.D. has a bored finish, not ground smooth. It's true, but has tooling marks. That's why I was thinking about a couple of tight-fitting O-rings on the O.D. of the plug, but I don't know that they would center up well enough.

Tom

 

[DCRYDER]

I meant making the delrin or aluminum "spindle plug" the opposite way that you're thinking which would center up in the bore. Just like the dead center in the tailstock, with a PROTRUDING cone. It would be 1 piece and universal. I think the o-ring idea is good, but like you said the bore is rough. I doubt the oring would survive the 12" trip!

 

[TRECustom]

DC, that makes sense. It would be very easy to make and quick to set up.

Thanks, Tom