Lets discuss the "other" method of barrel chambering. (kind of long)

I'm no expert here and still on the learning curve, but here's my experience in getting things to work so far.
With my SB 13x40 the shortest barrel I can use with my spiderchuck/outboard spider is 24" thru the headstock. Still my preferred method with best results.

Shorter barrels I've worked with so far have been old Rem 700 takeoffs, rechambered and put back on Mausers or other Rem 700's. What I did was make up a 3" length or so brass slip fit bushing inside the headstock which now has various ID's to fit muzzle and breech ends with .25 hole bored in the center to blow chips/oil out when chambering. I have a threaded cap and use extenders that help hold it all in together on the outboard end.

I mostly do 26" barrels or longer for F-Class/TR rifles, but for top quality short match barrels I've mounted the new barrels between centers and made an .200 long cut at the muzzle [to be later parted off and recrowned] to whatever diameter I prefer in my brass headstock bushing that fits snug. That's about as close as I can get the bore true at both ends with short barrels.

I've also tried to design various inboard spiders inside the headstock, but have not come up with anything workable yet. I originally tried a 60° cone to enter the bore, but the problem was getting it to stay all together in the setup.
 
At the match in Luther this past weekend, I shot out of a box of old Berger 68 gr bullets that were made probably 15 to 20 years ago when Walt was still pulling the handle. The box was sealed until Saturday. I was third at 100 yards with them. I don't have a doubt that they would shoot with any bullet made today. FWIW, the top 6 shooters at 100 were stacked in from .2836" to .2948", I had a .2926". Conditions weren't good by any stretch, but those old Berger's shot just as well as the newer made bullets.
 
I wish I had about 10,000 of the Fowlers I had in 1998. Or a whole bunch of the first Bruno 00's I had.

Great bullets, great barrels, and great tuning tends to make good shooters.........jackie
 
Mike,

About all I can say to that is, the guys who are responding with that sort of experience or guessing it to be that way, are shooting short range. If you were to ask guys shooting long range, I'd bet it'll be unanimously in agreement with what I had said. If there are some who'd disagree, they'll probably do so while referring to some hand made bullet that isn't available to the general public. Jmho.

Aggregate numbers in 1K differ greatly from short range. In the last 15 years, there's been an improvement in winning aggs of roughly 30-40%. That's a ton. Groups that were a once-in-a-lifetime thing 15 years ago, literally won't win relays today. I'm just saying that in 1K, I don't think it's the advancements in gunsmithing causing it.
 
4Mesh said:
Charles, do you mean that Dave was bearing on the uncut tenon, or on threads? You and Ray both mention this, but I'd be surprised if they were bearing on the threads as they chambered. jmho. I suppose it is possible, but I probably wouldn't, and no, before today, I'd never heard of anyone doing that, unless what you meant was to rough the tenon, then bear on it.
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No, the steady rest bearings were set to ride on the threaded tenon to cut the chamber.

IIRC, Dave didn't know why. It was just AFTER CHECKING THE WORK, he determined he got better chambers that way. BTW, those were the days when Dave growled if you called him a "machinist." He was a "gunsmith." Too many guys getting out of school who could only run a machine were calling themselves "machinists." I like to recall the 19th century use of "mechanic" -- not someone who bolted part A to part B, but someone who solved problems.

Whatever.
 
4Mesh said:
Mike,

About all I can say to that is, the guys who are responding with that sort of experience or guessing it to be that way, are shooting short range. If you were to ask guys shooting long range, I'd bet it'll be unanimously in agreement with what I had said. If there are some who'd disagree, they'll probably do so while referring to some hand made bullet that isn't available to the general public. Jmho.

.
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Phil, yes my comments were referring to 100/200. I'll readily agree that bullets for 600 & 1k are better now. Barrels are no better IMO.

As to running the steadyrest on the threaded tenon, for some it is a common method, BUT, you need the radiused bronze tips or the roller bearing tips to do that and still there is a possibility of inducing chatter. Most who use this method cut a tenon diameter to about 70-75% thread which leaves a nice flat on the top of each thread to run on. I wouldn't do use that method for a benchrest barrel but for an average BangumMagnum I might!!
 
Re putting the steady on the threads - I have my little gizmo that consists of a short barrel stub that's been bored and threaded to match the receiver. It's used to test the thread when you are getting down to the last cut. I'm sure everyone has one of these. Anyway, I screw this on the thread, take a very light cut to true it (less than a thou) and run it on the steady.

Going back to the "old days" - 15 years is not a long time when it comes to point-blank Benchrest, but it is a long time for long-range. There are many bullets that didn't exist back then, and cases too. But, bottom line is what 4Mesh said, advances in gunsmithing don't account for the smaller groups and/or higher scores of today.

Ray

Ray
 
For those with spindles too long to chamber short barrels, and use a bush to locate the barrel in the outboard end of the spindle. How do you machine the inside of the spindle true and if you use an indicator how true is the inside of the spindle?? Ian
 
Ian_Owen said:
For those with spindles too long to chamber short barrels, and use a bush to locate the barrel in the outboard end of the spindle. How do you machine the inside of the spindle true and if you use an indicator how true is the inside of the spindle?? Ian
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Ian, I would be suspect of any lathe that the ID of the spindle does not run true with the spindle OD. That said, in reality, there may be 0.002" or so runout in the bore but that, being more than desired, would in no way ill-effect the barrel fitting outcome.
 
Ian,
I'll just agree with Jerry here, and say that the spindle bore on a lathe is not perfect, but probably is as close as a barrel bore, maybe closer cause it's a bigger diameter:length ratio, thus easier to make.

Truth is tho, I can't indicate it any easier than I can the barrel. I trust my eyes. I know when a part is in a lathe and it's running out 5, I can see that while standing on my head. It's a mile. 3 is still way way visible, and even 1 is visible at the proper speed and looking closely. Something like a barrel muzzle has very little feature to it, so it's easy to see if it's running out. When I look down the spindle at the barrel, if it looks like it's out, I pull it, clean things and put it back. That's pretty much it. When it looks good, I assume it is well within any tolerance I'm going to accept.

Even if it isn't ok, we have people here advocating a lot more movement than I will ever have in a bushing, even if I made mine in a drill press by hand. (and I don't). Again, it comes back to what method you want to use, and what the person considers important. This very thread came from differences in opinion of what is or is not important. Fact is, nobody has shown their way or any other to be, so, who's right? Guns seem to shoot well regardless of chambering method, so it's hard to advocate one over another for performance reasons, that's why it's gotten down to machining disagreements.

Charles,
Interesting. I suppose then it's like Jerry said where he'd probably leave a small flat on top (as do I) and then use them to ride on. That's one I'd never heard. Of course, I don't go back and remove the flat later even though I don't use a steady, probably neither did he.
 
Steady rests themselves have many differences. Telescoping brass jaw types, ball bearing types, the old style SB steady with the slotted rectangular jaws, the latter of which I have always found capable of providing the most accuracy. Needless to say, Work holding has always been a key issue in machine work.
 
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A Note

One thing that you always have to be cognesant of when doing any type of machine work is the concept of "stacked tolerances". Any time you have to change a set-up, there is always that possibility.

Basically, this is the inability to get something indicated exactly as before when setting up to to another machining operation.

That is one reason I prefer to do all machining operations that have to run dead true with each other on the same set-up.

Once again, it goes back to checking, and proving your work..........jackie
 
Hi guys,

I finally got to where I could log on. Damn computers. Since my name was referenced a few times in this thread I thought I would clear up a few things.

I've chamber barrels every conceivable way possible and then came up with a few others as unique situations arose, except for Gordy's method. Not a slam on Gordy just never saw the need to explore that technique. Always though there was -- never mind.

When I started in this business I didn't have a lathe that would accept a barrel larger than 1.450" through the headstock. That leaves it doing it between centers and using a steady rest. I explored every alternative to determine the best way to run the barrel in the steady rest for chambering. Cleaning up the outside of the barrel while it was between centers and running the steadty rest on that, that I didn't like. It shouldn't matter but it did, too much runout. Then I went to the tenon. I got acceptable to very good results running the steady rest on top of the threads using the brass inserts not bearings. And yes I do have a pretty good flat on top of my threads.

I got my best results after a very wise man gave me a bit information one day at a match. I have never seen a discussion of how to put an accurate center in a barrel. This is the key to consistancy using this chambering method. In the past I always got a close fitting bushing and jammed the center reamer in until I had the depth I wanted. Thought I was good to go. There was one very important step I was ommitting. Here's how I do it. Set the barrel up either in the chuck if it will fit or run it in a steady rest and run it at about 100 rpms. Push the center reamer in by hand to the depth you want, here's the bit information that makes a big difference, with the lathe still running pull the reamer to one side until it stops cutting. You have just removed all the tolerences that stack up between the fit of the bushing to the bore and the bushing to the reamer. You now have a center that is in perfect alginment to the bore.

That wise man who gave me that tip was George Kelbly at a 1k yd. match. Thank You Sir.

Since then I have no reservations about chambering a barrel between centers. I don't have to these days unless it's a really short odd barrel and I'm not tooled up for it on the Haas. I have three lathes a 10X30 Nardini, 14X40 Clausing Metsoa ( over priced medium quality lathe BTW ) and a Hass TL-1 that will handle anything I want to put in it. I chamber everything up to 50 cal's on the Haas. From 14.5" to over 30" length barrels. Obviously there are some new and different setups to handle that assortment on the Haas. Many of things I anguished over for years which I don't do anymore just don't show up in the chamber or on the target.

The work I do on the Haas sometimes requires the use of bushings on either the muzzle and/or chamber ends of the barrel. I will not disagree that this isn't perfect but it works for me with no apparent or measureable compromise in quality.

Dave
 
A friend of mine, who is a barrel maker and gunsmith was rechambering a .50 cal one day. I guess the guy wanted a different chamber than his custom came with and didn't want to ship it back to wherever it was made. He has a DSG that he uses for contouring barrels. He chucked up the muzzle with card stock around it in a set-tru type 3-jaw. He then put the threaded tenon in the steady with the brass tips. With it centered, he brought the steady points up and lubed them and cut his chamber.

He then used a center to hold it and cut a couple more threads to gain what he had cut off. The 3-jaw did not damage the threads for the muzzle brake and he did not mar the finish on the barrel (Robar companies Rogard)

Apparently it shoots spectacularly now so this method worked fine.
 
Dave Tooley said:
Hi guys,

I finally got to where I could log on. Damn computers. Since my name was referenced a few times in this thread I thought I would clear up a few things.

I've chamber barrels every conceivable way possible

Dave
Click to expand...

And that is the truth!! Let me say something about my friend Dave Tooley. I notice several of you on this thread and this forum are new or recent to benchrest and may not know Dave.

Dave has, with out argument, chambered more winning long range benchrest barrels than anyone I can think of.

Dave has chambered literally thousands of barrels if not tens of thousands for benchrest, varmint and hunting. Not only long range benchrest but also short range benchrest. He has chambered over 300 barrels just recently on special requests.

If you wanted to read a book just on chambering accurate rifles Dave would be the gunsmith to write it.
 
JerrySharrett said:
And that is the truth!! Let me say something about my friend Dave Tooley. I notice several of you on this thread and this forum are new or recent to benchrest and may not know Dave.

Dave has, with out argument, chambered more winning long range benchrest barrels than anyone I can think of.
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More in the interests of completeness, when it comes to "winning barrels" (rifles), Dave has built a number of record-setting short-range benchrest rifles too. And I think he secretly has a real fondness for building hunting rifles.

So as not to single out one guy, there are a number of gunsmiths, including more than a few who post here, who have a similar "record."

If I have a special fondness for Dave, it's because he's one of the people I know who has given back quite a bit to the benchrest community. He's also the guy who reminds me -- often -- that most things in precision shooting involve compromises. Sometimes there are clear pluses to a decision, and sometimes not. That's important to remember with all this talk about "the best."
 
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I came here to this site with an open mind and the desire to learn, and have not been disappointed. Thank you for the Post Dave, and that little tweak from Kelbly, Nice.
 
This an older thread some of you new to precision barrel fitting might enjoy. Especially posts from some really knowledgables like Dave Tooley.


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Just acting as a reporter, and nothing more, there seems to be one more "over the bed" chambering method. It involves what may be described as a mid bed half headstock. Speedy has published a plan for building one, and I know that Chet Whitebread has made one from an extra 9" SB headstock that he split in half. I have heard of others making them as well. Instead of having to machine a concentric bearing surface for a steady rest, these have an integral bearing that is true to the CL of the main headstock, and opposing screws that work like any other spider, allowing the barrel to be indicated in, either all at the breech, using a four jaw to control muzzle offset, or at both ends, with both ends centered, which would require a truing cut to be able to indicate concentric with the bore at the muzzle off of its OD.

I understand that it is possible to set up a barrel, chamber it a little long using a floating holder, re-indicate the barrel from the chamber, and then cut the tenon and shoulder. I have also been told that barrels can shift slightly when set up using copper wire to allow them to pivot in chuck jaws, under the force of making the rough cuts for the tenon OD. One smith that I know rechecks his setup before making his finial cut on the tenon OD.
 
Since this has been resurrected, I guess I will make the same statement I have made in the past.

It makes no difference how you do these operations, the only thing that counts, (from a purely machinist viewpoint), is results. That being, is the chamber, thread, shoulder and any other subsequent operations square and truly straight with two predetermined points in the barrel, and are the final dimensions and finish of the chamber what you wanted.

The reason I say two points is because when dealing with a piece, (i.e., the ID of a barrel), that is not straight with it's own self, all you can hope for is to get two points true.

Be willing to check your work. How many of you actually do?

Better yet, how many of you actually know how.

Truth is, matches are won every weekend somewhere with barrels chambered by shooters who at best possess the machinist skills and knowledge of a first year apprentice . They use good common sense, think about the requirements of the job, and do it.
 
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