oversized chambers

[hpdrifter]

I am gonna put a 38-55 barrel on an old Win 94 30-30 that I have. I am not TOO worried about doing it. I know it could turn into some work, but I'ma doing for learning purposes and tohave the 38-55.

My main question is about the chamber. Should I get lucky enough to have to touch up the chamber for some reason, how does one go about controlling the size of it. Are you at the mercy of the reamers available? Are special reamers out there to prevent getting oversized chambers?

Seems like every gun that I've bought for the last 5-7 years(after some education at this and other websites) has grossly oversized chambers. Almost all the 30-30's have a slight swell infront of the web after firing, a 45 colt Rossi 92 had to be sent back because of this.

Since I'm gonna do this meself, I want to get a proper chamber.

Any advice, knowledge, offerings out there?

[versifier]

Honestly, the best way to learn how to work with chambering reamers is to use a couple of worn out barrels and practice on them first. Cut the threads to fit the action and make the sights (if already there) line up properly, then cut the chamber and learn to use the feeler and headspace gauges while you get used to the feel of the reamer cutting. Then use the cutoff tool and try it a few more times. It is made much easier with a collet holder for your lathe, but that isn't absolutely essential. Don't chuck the reamer in the tailstock chuck - it is easier to use a tap handle and stop it on the tool holder as you have to remove it often to clear the chips and reoil it. It's much, much better to make a few mistakes practicing on a dead and worthless barrel, because you will make a few mistakes, it's inevitable, and it's much nicer to not make them on an expensive blank.

[hpdrifter]

Ok, I got all of that, but what I want to know is: If reamers come sized properly or do you just have to bite the bullet(no pun intended) and live with oversized chambers if you don't cut your own reamer?

With the 38-55, being a tapered case and it headspacing on the rim, if I stop short of bottoming the reamer the diameter at the case mouth may not be the correct size. I don't want my brass(it's expensive these days) to have bells above the web.

[Dale53]

I have had good luck talking directly to my reamer provider about my concerns. My provider happens to be Clymer and they are VERY helpful. I would suspect that most of the good reamer people are pretty much the same way.

Dale53

[Jon K]

hpd,

Are you using a barrel blank or an already chambered barrel?

When ordering the reamer, you supply the drawing and specs to grind to.
Most Lever guns have a large chamber, for feed and cycling. A lever will never have a tight bench rest tolerances.
The 38-55 usually has a lot tighter chamber than the 45LC & 44 mag. I think the tapered chamber allows it to chamber reliably without putting in extra clearance.

If you are using a blank, you should rough bore, or have a roughing reamer, then a finish reamer.
If you are re-cutting, you might want to stop short and hone and polish to match, so as not to have a witness mark and oversize chamber.

These are just my observations, I have never done a Lever action, only bolt action and single shot pistol.

Have Fun Shooting,
Jon

[hpdrifter]

thanks for the replies.

This is an octagon barrel, already threaded, chambered, dovetails cut, etc.....

Probably have some extra work because of this, but if it is close, it'll save some work also. If it lines up or indexs too close "out of the box", I'll live with the chamber as is if it is ok. However, if I have to set it back a thread or something, I'd prefer a close chamber.

Thanks for input.

[Jon K]

hpd,

Did you chamber cast and measure the chamber?
Screw it on the action and see where it locates.
The original brass is 2.130 and current production is 2.080. You can calculte and turn back oal to index the barrel to square. I have a 1980 Win OFW Commemorative, it will only chamber up to 2.090. I guess you should be able to do what you need to make it fit, and still have a close fit, with only minor clean up modification.

Here's another vote for Clymer. Good people, easy to work with.

Have Fun Shooting,

Jon

[Char-Gar]

Drifter.. Most, if not all, of those eggs in the chamber don't come from the reamer, but from the improper use of the reamer.

If you buy a reamer from a quality maker (Clymer etc.) the reamer will be correct and not cut oversized chambers.

[versifier]

You have to remove the reamer often, clean and reoil it. The chips can catch under the cutting edge and really make a mess of things. The most common mistake is not being patient and not cleaning it often enough to "save time".

[Ken O]

I am trying to picture what you guys are talking about. I am no machinest, but am interested in how its done.
Do you put the muzzle end in the chuck? It seems with a long barrel it would be suspended with out support for the reamer. I have some 30" match barrels and I wondered what size lathe it would take to chamber them. Is there a chuck type where the barrel could go all the way though like some of the industial pipe treading equipment?

[Char-Gar]

The barrel muzzle end goes into the lathe headstock. How far depends on the size of the hole in the headstock. The chuck is adusted to center the barrel and and a steady rest is used to hold the breech end. The barrel is centered again with a dial indicator. The reamer is held by a center in the tailstock and fed into the barrel by turning the tailstock inward. The reamer is held by a wrench to keep it from turning.

There are several ways of doing this, but the above is the most basic. There are gizmos that can be used to hold the reamer etc. etc.

There is lots of math and stuff to determine the depth of the chamber.


Like all machine work, set up is 95 percent of doing the job right.

[Jon K]

KenO,

What Chargar said is basic set up.
What you asked about putting the barrel thru the headstock can be done. It is not the size of the lathe but how the lathe is built, not all lathes are built to rear feed, if the lathe will accomodate the barrel diameter, you can build a tapered support for the lathe. The tapered bushing support needs to be 2 piece or close to size(will work like an external steadyrest) Indicate both ends for runout
The chuck also has to be able to accept the barrel OD.
The advantage to keeping the work close to the chuck/spindle bearing is rigidity.
Like Chargar said there's lots of different ways to do things.

If you want to tinker and learn, check out the local community colleges. They usually have some pretty good machinery, and they take good care of it.

Jon

[Ken O]

Thanks guys, I have checked into the local community college, and there are no programs. I am thinking of picking up a lathe and trying to learn with a correspondence course. There is no hurry since I am retired, but it looks like a lot of enjoyment.
My Dad did this most of his life, then lost interest and sold all of his stuff. He liked to make steam engines, and the Sterling heat engines were his favorites. He is 86 years old now and still talks of the fun he had in his shop. He lives a long ways away, otherwise I would have a teacher.