What size D1-4 Backing Plate to make a chamber jig out of 4" DOM?

[unioncreek]

BP,

Great job on the cats head. Wish I had a bigger lathe, so I could increase the variety of jobs I could do. But, right now I have very limited space so the 8x12 is going to have to do for now. As long as I can get the jobs done that I want to do right now it will work.

Bob

 

[ridgeway]

BP...thanks for taking the time to post some pictures! Very nice set up indeed!

I have yet to actually chamber a barrel. I am slowly getting tooled up to do so. I'm almost ready though. With that said, I just finished making an outboard spider and just had to try it out. The barrel is already chambered(not by me), Krieger 6mm HV 4 groove. Chambered for 6 Dasher. Its actually my fireforming barrel.

I set it up in my 4 jaw with a 4 gauge copper ring between the jaws and barrel to act as a pivot. I just wanted to dial in the muzzle end using my spider to see how its done and how close I can get it. The spider end was actually easier to dial in than the chamber end. Maybe its my Chinese 4 jaw and the crude movements? This is why I think a chuck side spider would be much easier to work with and dial in?

Anyhow, here is my video and pictorial of my first dial job!

[video=youtube;ofKtO6t4UQo]http://www.youtube.com/watch?v=ofKtO6t4UQo&feature=youtu.be[/video]

 

[bptactical]

You have the right idea but invest in range rods or at the least gage pins to put in the bore to indicate on. With your needle jumping around over the lands and groove you introduce an opportunity for error by whacking the zero. It is also hard as hell on your indicator.
Also if you use a similar rod for the chamber end you zero in on the actual bore rather than the chamber and can correct(as long as the barrel blank chamber is undersize) for chamber misalignment
Your right about cheap chucks, the first one I had was miserable to adjust precisely so I kept my eyes open and found a 8" D1-4 Atlas for $150.00 here: http://www.lostcreekmachine.com/metal_lathes.htm
Ahhh, decent jaws and screws make life easier.....

On a side note, I really like Lost Creek Machine, they have some great deals and are like the Sears Wish Book for our toys )

 

[ridgeway]

Thanks for the suggestions. I still need to get or make a reamer holder and some indicating rods. Would you suggest range, indicator or grizzly rods? From what I read, they all have their ups and downs to them.

 

[ranch23]

View attachment 59481View attachment 59482

 

[ridgeway]

Pretty nice ranch! Seeing you welded it it...TIG maybe, how true does it spin? Back plate warp at all?

 

[ranch23]

TIG, yes, no warp at all, the backplate is thick enough to not heat up. Was very careful in construction so ran almost dead true. Then I took a cleanup cut after it was finished. I index mark all of my chucks so that they all are as close to zero as I can get them.