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chriskat
01-11-2010, 09:48 PM
Made a little more progress. Below is a picture of the various parts I have made to date. To center is the receiver, you can see the extractor housing in the lower front of the receiver if you look closely. Clockwise from the receiver (roughly) is the pivotal bar with connects the trigger group to the breech block. The pin for the hold closed plunger, then the hold closed plunger. Next the trigger housing. Lastly the breech block.

http://home.comcast.net/~chriskat/Vault%20Lock%20Rifle/DSC_1007%20%5B640x480%5D.JPG

Close up of the breech block and receiver. You can see the slot for the pivotal bar and the extractor housing better.

http://home.comcast.net/~chriskat/Vault%20Lock%20Rifle/DSC_1010%20%5B640x480%5D.JPG

Assembled with the action closed.

http://home.comcast.net/~chriskat/Vault%20Lock%20Rifle/DSC_1011%20%5B640x480%5D.JPG

And with the action open.

http://home.comcast.net/~chriskat/Vault%20Lock%20Rifle/DSC_1012%20%5B640x480%5D.JPG

Jeff

chriskat
01-11-2010, 09:55 PM
I also have a question. Shortly I'll be threading the barrel. I plan on indexing the breech end of the barrel in my four jaw by indicating on the bore.

My thought is to use a piece of 10 or 12 gauge bare solid copper wire, because I have it around, as a shim between the chuck jaws and the barrel.

Once I get the breech end indexed with no runout I'll use my spider to make sure the bore is running parallel with the head stock of the lathe. To do that I came up with this.

http://home.comcast.net/~chriskat/Vault%20Lock%20Rifle/Aligning%20Bar%20%5B640x480%5D.JPG

The small end is a smooth slip fit into the bore, no wobble. My plan is to index on the larger end 4-5" from the breech end of the barrel and adjust the spider to get no run out there. Once that's done I'll re-check the runout at the chuck, indexing on the inside of the barrel, then one more time at the end of the bar above.

Sorry I didn't put a scale in the drawing. The small end is about 2" long and the larger end around 6". Total then just about 8".

Seem workable?

Jeff

38_Cal
01-12-2010, 10:03 AM
As long and heavy as the large diameter end is, you'll probably get some deflection. It only needs to be long enough for the indicator to bear on it. Half an inch is just fine. The way I do it is to rough indicate the bore at the breech end, indicate the muzzle end at the spider and then get the breech end to under .002". I'll then double check the muzzle and adjust it as needed to under .001", then back to the breech to under .001"...usually to less than .0005". It takes a bit of time, but it's worth it. I'll then thread and chamber the barrel. For chambering, I use a floating reamer holder from Manson Precision. I use brass shim stock between the jaws of my chuck and the barrel, as well as around the barrel at the spider.

David

mattm
01-12-2010, 06:39 PM
I have only done a couple of barrels but what I read and it seemed reasonable is to use the wire as a ring at the breech end. This keeps the flat jaws from bending the barrel when you are pushing the muzzle end with the spider. So that is what I did and it seemed to work.

matt

s7hss
01-13-2010, 10:55 AM
Jeff,

The ring idea seems reasonable, long as you don't push the cuts hard. Have you the ability to turn the barrel between centers? I'm guessing not as it may simplify turning and threading the barrel.

Tom

Chip Soles
01-27-2010, 09:27 PM
Hello Jeff, If the front face of the receiver is ground square to the top, and bottom edges, you would probably get just as good a result by indicating that
face to less than .0005". After 42 years of building tooling of various types, I might use pieces of .06"-.12" alum. to pack the chuck jaws, to stop marking.
Get your face to zero, with the jaws slightly loose, and then snug them up a bit at a time. Tap the face with a piece of alum. rod, and a gentle ball pien
hammer. Small, narrow, strips of shim may help to tip the block, by adding,
either at the top or bottom of the jaws.
Regards,
Bob

Chip Soles
01-27-2010, 09:49 PM
Ooops! Its time to go to bed. I can't read.
Jeff, I gather that the muzzle end is protruding from the left side of the headstock. And the breach end is in a four jaw chuck. If the gear housing is
non magnetic, epoxy, a piece of 3/16"-1/4" steel to it to support a mag. base.
You can then indicate both ends of the barrel, independently, finishing up with the bore on the breach end. A .0005" test indicator will give you all that
you can get with the rod, without worry about scratches in the bore, or any movement, at the end.
I appologige for the first post, as I saw after I hung up that the breach had been bored, and threaded.
Is this your design? will it be a rimfire?
Regards,
Bob

rws
01-28-2010, 09:02 AM
Jeff,

Your method of indicating the barrel is done by some very experienced riflesmiths. Others indicate the ends to zero.

No rifle bore is straight, it's a given. By using the long rod and "walking" the breach end to run concentric ensures the chamber is heading straight into the bore. Depending on the barrel and how straight the bore was drilled, you may be very surprised how much run-out you have on the muzzle end. And your use of a copper ring also ensures there is no bending while indicating. Just use very little jaw pressure during the initial indicating, letting the barrel move where it needs to be.

The only downside of using this method, again depending on the bore straightness, it may be quite a bit off on point of impact. A very well known long range smith "clocks" the barrels when threading so the barrel run-out is up, which helps with scope adjustments at 1000 yards.

Short range smiths usually don't bother with the bore run-out, and indicate each end to zero. It has never been proven one method creates a more accurate barrel than the other.

There was one barrel maker, that made very successful barrels, drilled a very crooked bore. When you put in through the headstock and dialed it in, a queezing feeling of sea-sickness would come over you watching it rotate. However, they shot great! There is no real excuse for a barrel maker to drill such a crooked hole with today's tooling. When I get a barrel, before I do aything to it, I clean it, indicate it in and see how much drift is in the bore. Then I run reamer bushings carefully through, increasing the size, to feel how well it was lapped and how consistant the bore is. If I feel a tight spot or see too much wobble through the barrel, I send it back.

The most important point of the chamber is at the throat. The chamber must be dead center aligned to the bore/groove diameters. The use of piloted reamers helps a great deal here. Get a good fit in the bore, not too tight where it marks the lands, and you will do fine. There are other ways to skin this centering cat, but this one will do well.

Bob Ford
01-29-2010, 04:00 PM
Pinging Chriskat

did you get my email pictures?

Bob

chriskat
01-31-2010, 07:31 PM
Bob,

Sorry I haven't replied sooner, but no I didn't get emailed pics. Could you resend to chriskat@comcast.net

Also, I have a question about your "home made" reamers. You mentioned in another thread that you ran a roughing reamer all the way in with no pre-drilling. Did you make a seperate roughing reamer? Or did you just cut the entire chamber with the reamers you made?

Jeff

Bob Ford
01-31-2010, 09:42 PM
Jeff

I make ruffing reamers .005 - .010 smaller. To me a ruffing reamer is used to insure that you follow the bore.
With shorter cases I have used the finish reamer to cut everything. If you use a finish reamer to do all the work, you must be extremely careful to clean chips often or you will score the chamber.

Bob

chriskat
01-31-2010, 09:52 PM
Thanks Bob, I guessed that was what you did. I'll give it a try this week.

Got the emails, thanks for the pictures they'll help.

Jeff