Oh No......

[PIKELAKE]

Well, not quite as mad but still mad. I took the advice to get a hold of my machinist buddy and let him take a look. It seems that all is not lost. My ragged hole was not that bad. He helped me round it out and I will have to use a larger liner. We both believe that I can get that larger liner to work. Next time I will start with a smaller liner for sure. Cody and birddog6, a new barrel would probably be the best bet if I was making this rifle for someone other than myself. But like I said, the rifle was for the most part finished and I would be getting into a lot of work to refit a new barrel. Nate, I always remove the plug before drilling a liner hole. The drill bits I use are job specific and I buy them from a production tool store; not the most expensive but not the cheapest either. I have made notes in my journal; the journal of goofs. I have always used liners and will continue., not till next week anyways. Thanks to everyone who took the time to offer advice. I learned a lot and will get a machist manual for sure. Feed speed eh ? Never thought about that. And billd, I think the drill bit took a hit when it was breaking thru. Thanks again everyone.  JZ

[D. Taylor Sapergia]

John, may I presume that you had the barrel held tightly in a drill press vise, and that the vise too was clamped to the drill press table?  Holding metal down with one hand and feeding in the drill with the other, is asking for trouble, and can/will cause serious bodily injury.

[PIKELAKE]

Taylor, thanks for responding. Yes, I use a drill press vice that  is locked down on the table and the barrel is supported on the free end. Like I said, I have drilled maybe a dozen holes for liners and never experienced a problem before.  My guess is that the bit may have had a fracture that I failed to notice. I threw that bit away. From now on I think that once I have the lock and barrel set into the wood, I will drill for the liner, instead of finishing the rifle and then drilling. I believe it will all work out.  I really enjoy your work by the way; good stuff. Still mad though...  JZ

[The other DWS]

This is a very informative thread, especially for guys like me that have no machinist training.  I have a cheap chicom drill press--5sd by moving the belt and various hand held variable speed drills.  I've always operated on the principle--fast on soft stuff and slow on hard stuff.   I guess I've been lucky so far---biggest issue has been misaligning holes for the pins.  but then I still have to drill the hole for the liner on my current project

you mention bits breaking as they cut through to clear on the back side of a hole.  I have had that happen on occasion.  What causes it to happen?

[D. Taylor Sapergia]

Sometimes where a bit is breaking through the far side, there is just too much metal for the flutes to carry it up, and the drill goes from 2400 rpm to 0.  If it doesn't slip in the chuck, which often happens, the drill shatters.  Meanwhile, you're still applying pressure, and the broken stub is pressed into the pieces of jammed drill bit and the hole, causing a catastrophic pit rather than a nice clean hole. 
I'll bet you won't do it again, now that you know what that breaking through feels like, and you'll bring the bit through the other side with control.

[Daryl]

?Or have Taylor do it for you

[bluenoser]

Well put Taylor!!!

I suspect breaking through and running the drill too slowly will increase the chance of failure.

Laurie

[ehoff]

One thing no one has brougt up is the use of a piolt hole. Using a piolt hole at then working up to the correct size drill helps avoid this as the drill does not have to remove as much material, at least that's how the instructors taught us in tech school.

[D. Taylor Sapergia]

That is excellent advice Ehoff.  Even with a 1/4 x 28 liner and the # 3 drill for the hole, it would be BEST to drill a pilot hole...say 7/64" first.  Then the # 3 drill will follow that hole precisely, with much less chance of a problem.

[Darkhorse]

If your going to be feeding that drill press by hand then developing a sense of feel and touch is essential. 9 times out 10 when a drill breaks when breaking through your material it's because your putting too much pressure on that feed handle.
This goes for both drill presses and hand drills. The other 1 time it's because your set up is not rigid and the drill twist pulls it off the table suddenly and uncontrollably increasing your feed rate.
When I started in the Tool & Die trade 40 years ago we drilled lots of tool steel with primitive equiptment. Developing a sense of touch was imperative.
I always run my speed on the high end of the band for the material I'm drilling. (but not above the recommended speeds)(infact, I don't even look at the books anymore. When it looks right I drill) Less feed and more speed! Along with plenty of cutting oil.
I bet most of these guys who's been doing this awhile have developed that sense of touch without even realizing it.
When doing a swamped barrel, I lay out the position of the hole with the barrel and lock in the stock. Then remove the barrel and using a level I clamp the barrel so the "Center drill" (always use one) goes straight into the flat. I also drill mine with the breech plug in place (heresy I know). I turn the RPM's up and feed lightly and feel when the point begins to cut through. Then continuing to feed lightly and with strict control I just touch the plug. Or not. This tells me exactly what I need to file and polish out if indeed there is interference between the liner and plug.
When using a pilot drill or a center drill be sure the hole is larger than the thickness of the web of the tap drill or it may still run off center.
I know my habits may bother some but I've been doing this stuff for a long, long time and I just do it.

[billd]

 I would use a center drill and then go to the full size drill rather than using a pilot drill. The smaller the drill the better the chance of it breaking or walking. The following drill will follow the pilot hole wherever it goes.

Darkhorse made some very good points in his post.

Bill

[PIKELAKE]

Well since this post was resurrected again I will have to admit that my fix did not go too well. I had hoped that a larger liner would be the answer, but it was not. Infact I called Barbie today and ordered a new barrel.  Now the fun begins. I will have to fit a new barrel into a rifle that for all practical purposes is finished. It will be awhile before  I can start this new adventure. I'll need that time to calm down. Not so much mad anymore but very disappointed. Thanks again to everyone. Will I get over being gun shy on drilling vent liner holes?  Hope so........JZ

[44-henry]

Did you ever consider having a patent breech made for the barrel in question. This would solve the problems and you would only have to re-fit the tang. In any event, I'm sure you can find a good use for the shorter barrel on another project.

[Black Jaque Janaviac]

John,

I was going to suggest that you fix her up as best you can so that she is at least functional if ugly.  Then sell her at a really good price.  That way the buyer is really happy that he got such an awesome deal on a gun that only had a buggered up touch-hole.  And you won't have that ugly thing staring you in the face every time you open the gun cabinet.

Sounds like you're going the route of entire barrel replacement.  Let us know how that works out because I'm curious if it can be done.