Dialing in the bore

Schulze · Aug 15, 2003

Ok here it is. I dont have a cat head to slap in the back of the spindle bore to dial in the muzzle end. This is a Krieger barrel and I need to set it back and rechamber. Can I get away with just indicating the bore on the chamber end? I believe I can but this is a 30 inch long barrel I am working with.

Rifle is a 308 win Palma gun

CBlair · Aug 15, 2003

Schulze;

Forgive me but why don't you have a cats head? You have a lathe and they are very easy to make. I have made several of them for various lathes in the past. For barrel work I put nylon screws in them to keep from marring the barrel. If there is enough room you could also use a tapered sleave on the barrel that is a close fit in the spindle. This is of course assumeing that the outside of the barrel is true to bore.

Charles

Schulze · Aug 15, 2003

I am running out of time to make one at the shop up at gwinnett. I have a major match in october and I need atleast 2 weekends of training. I can make one in a snap but it is finding the material is the hard part. MSC wants a good bit for delrin type stuff I have about 8 class sessions till the qtr ends and I have to make some tooling. But I dont know how long it will take to make the actoin rod, hopefully less than an hour.

ANy materials you can recomend to make one for? Also since I have so much sticking out the back end, what would I set the mag base on?

CBlair · Aug 15, 2003

most of the ones I've made I use aluminum, just because thats what I have laying around. Steel will work great and even brass will do in a pinch. A friend of mine in NC made one out of hard rock maple with brass screws. It does not have to hold on to tight as the force is at the other end. As far as the dial indicator goes...Thats a good question, I'd have to see your setup. I have never done such a high end barrel for that level of accuracy so my setups may not be sturdy enough for you or else I would be happy to let you use one of them. Of course mine probably wont fit your lathe anyway.

Hey are you useing one of the school lathes, if so which one?

Charles

Schulze · Aug 15, 2003

Going to use one of the colchesters. I like the threading on it better than the southbend.

[This message has been edited by Schulze (edited 08-16-2003).]

rws · Aug 18, 2003

My lathe has a cast cover on the far left end that covers the belt and gears that is attached by two studs with knobs. It's pretty rigid when tight.

I drilled and attached a piece of angle iron to the cover the distance below centerline of bore the same height as a magmount and dial indicator. I set the magmount on it to indicate the barrel. Works good.

wallyw · Aug 18, 2003

Assume a spindle OD of 2.000". Get some round cold rolled, aluminum whatever of about
2.500". Cutoff and face to about 1.500". Bore it to ID of outboard end of spindle. Bore one half (3/4").

Set piece in a mill vice and drill through piece. Rotate 90 deg and drill through once again. Insure you drill through end bored to ID of spindle. You now have four holes at 90 deg. Tap for your bolts. Epoxy to outboard end of spindle.

If you need to be able to remove spider you can attach it to spindle with a couple of set screws. Better yet bore spider 0.250 or so less than spindle ID and thread to fit spindle.

Take just about as long to describe as actually doing it.

Wally

John Ricks · Aug 18, 2003

Steel, Aluminum, are ok. Don't use plastic, you will strip the threads. I will send you a photo. Put in 4 screws, three is too time consuming to align the bore.

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Dialing in the bore

Schulze

Aluminum

CBlair

Diamond

Schulze

Aluminum

CBlair

Diamond

Schulze

Aluminum

rws

Cast Iron

wallyw

Plastic

John Ricks

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