Reaming to 50

I need to dill and ream a barrel from 45 to 50.

What is the absolute best way to cobble together the bits and reamers from standard off the shelf stuff I can get at the hardware?

This is a cheap CVA tube and I am not paying a bundle for the fixings or sending it off to have it done "right". I am also not going to use a good 36" piece of octogon stock for a tomato stake!

It's been "not much of a rifle barrel" for around 20 years and I guess now it will be "not much of a snooth bore" for another 20!

Only good thing about this barrel was that it would group better with a bare ball than with a patch! It would do consistant 4" groups at 25 yards without a patch. I always figured that some of the pitting caught the ball and gave it just the right spin or something. :rotf:

 

[TANSTAAFL]

Bit of a chore involved, but with that said and if me, and if my math is right. A 31/64" bit at .4844" diameter will leave 0.0156" to ream. (but only .0078" of material is actually cut) Off the shelf job bits normally drill a little over sized, which in this case is a not a bad thing.

A spiral .500" LH reamer will give a finished .50 bore, then hone and polish if desired for better surface finish.

An extension of appropriate length made from 7/16" (or turned down 1/2") bar stock will be necessary, drilled 5/16" on center in one end. Tool shanks will need to be turned down to 5/16", fit into drilled hole of extension and welded, silver soldered, or pinned in place.

Keep feed slow, don't hog or force, tooling well flushed with oil and use a LH spiral reamer with RH cut, as this helps keep the chips moving ahead as reaming transpires.

(A 12.5 mm drill would put it at .4921" with only 0.0079" material to ream)

 

[Birddog6]

I think you will end up with a .50+ cal roughbore, cause by hand you have no way of drilling or reaming it straight & honing it evenly & etc. However, it is something to tinker with. :hmm:

:hmm: Gonna be slow going too or you will bind the bit. If you weld a bit to a rod & use that, after the bit gets into the barrel full length there is no way for the chips to come out, so you will have to drill & back out, dump chips, drill again, back out & dump chips, etc. Like I do on a RR hole on a stock.
You will need a good cutting oil also & a bit that cuts slow as you will have a problem with the bit wanting to grab since you are starting at a hole .45 plus rifling depth on each side of ? .010 .....
Just thinking, it hits me that will really bite on & grab the bit when doing by hand. You may be better off to drill it to a .54 cal if ya can as that gives more of a surface to cut & the it may not grab as bad. :hmm: That is if ya got enough barrel to bopre out to this.

To hone it take a piece of 5/16" or 3/8" allthread & use a hacksaw & split the end of it about 3". Then get some emerycloth & tear into strips & slip into the slot in the allthread,wind up tight & get it to where it will just barely start in the hole & use the drill to turn it. Make sure you rotate WITH the wind of the emery & don't reverse rotation of the emery wind, as it will end up binding it & then have a H of a time getting it out ! (Been there done that !)

I have honed a few old shotgun barrel like this & just go finer & finer & then got to a swab with valve laping compound & and then JB Bore paste etc.

Also have sanded allot of RR holes in stocks with this same gismo. Ya ever get a RR hole & get all the pipes & entrypipe in & the rod continues to bind ? Take this with some coarse emerycloth & work it into the entrypipe & RR hole & it will smooth out that problem area. Just remember to take it out often & get the dust out or you will bind it up. And it works best with Emerycloth, not sandpaper. Emerycloth is much more tear resistant.

:thumbsup:

 

[bob1961]

why not just make a smoothy out of it to the safest wall thickness :v ...........bob

 

[wszumera]

I'm thinking that you will want to grind a pilot on the drill bit to center on the rifling.

Clutch

 

[benvenuto]

three fluted drill followed by a reamer and hand lapping?

 

[Jim-Iowa]

Best advice I can give is to go over to Bookies site. Toad Hall Rifle Shop, He pretty well describes the process he uses.
Get his book on the Iowa Rifle Bench and he shows exactly how to make the tooling to ream and rifle your barrel.
Since He is one of the few who do it this way I'll post a link.[url] http://www.midiowa.com/toadhallrifleshop[/url]/

 

[John Taylor]

I tried doing a few with hand tools many years ago, it don't work so well. If you use the old square reamer with a wood adjusting stick you will have the smoothest bore but you still need somthing to kepp it going strait. If you plan on using a drill to take out most of the metal it will need a pilot or your bore will not be strait. It's still better to use a lathe to help keep things going strait. Unless there is oil pumped through the reamer it will build up chips and not leave a smooth finnish. The old square reamer can be set to take a very small amount so the chips are not a problem.
I have found that barrels with rust can have pits that won't clean up even if you are taking out 1/8"