Different ways to chamber a rifle barrel?

The part I don't understand:
Now make the reamer to the case dimensions, which is also your die specs.
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How can all three (sized case, chamber and reamer) have the same dimensions and still work? Fired case dimensions are always smaller than chamber dimensions; at least in all my stuff.

How much shorter do you make the die headspace (die shoulder to shellholder bottom when they're touching) than sized case and/or chamber headspace?
 
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Take the specs off a RESIZED case. The body of the reamer can be exactly to size. The neck has to be slightly larger than the case. Actually, I usually used the low SAMMI print spec on the neck. Use the freebore specs from SAMMI also.
 
Take the specs off a RESIZED case. The body of the reamer can be exactly to size.
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If you think that's what is needed to well align bullets with the bore, note that a .243 Win. cartridge whose body is .010" smaller in diameter than the chamber around it will perfectly align its neck and bullet with the bore in a .308 Win. chambered barrel.

Rimless bottleneck cases headspacing on their shoulder center up front by their shoulders mating perfectly with the chamber shoulder when the round' fired. Body clearance to the chamber walls is not an issue except the back end of the case gets pressed against the chamber wall by the extractor's pressure on the case.

Where does the shoulder on a .243/.308 Win. GO headspace gauge center when it's pushed full into the chamber and its body is smaller than the chamber body?
 
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Bumblebug, I did not watch the video but by your description he gave up. I have rifles with chambers I did not cut, not a problem, to fit a case to a chamber I start with a case that will not chamber, example: 30/06 chambers, everyone knows a 280 Remington case will not chamber in a 30/06 chamber because the 280 Remington case is .051” longer than the 30/06 case from the datum/shoulder to the head of the case. Benefit? A reloader can not miss if they have a press with threads and their die has threads, meaning the press, die and shell holder are adjustable.

Bump, reminds me of the day I was sent home from school, had to do with what I said and what she thought I said (that is not the reason for being sent home), I was sent home after I clarified what I said and what she thought I said. Back to bump, When forming/sizing I have scribed cases at the case body/shoulder juncture, the illusion/perception reloader have when sizing is the shoulder moves, another of those ‘not fair’ things, My shoulder are erased, they do not move, the shoulder when sizing and forming stay in the same place, when forming and sizing my sizing die establishes a new shoulder. Then there is that long boring story about what happens when the firing pin strikes the primer, again, not fair, same-O, same-O, I have scribed the case body/shoulder juncture on cases that could be described as fire forming, again, the shoulder did not move, part of the case shoulder became part of the case shoulder and part of the neck became part of the shoulder, the scribed line on the case did not move.

As to the video on utube, I am not the fan of taking short cuts that put a builder into a dead run, he passed up a good opportunity to lecture? on the difference between go-gage length chamber and minimum length/full length sized case. Back to chamber I did not cut, I can size cases to a chamber with .000 clearance, meaning the bolt face is touching the head of the case and the shoulder of the case is touching the shoulder of the chamber when the bolt closes. Again, chambers I did not cut, and back to the utube video, Because everything about my presses, dies and shell holders is about adjustment I can size cases for his (utube) short chamber, I can get clearance, I can size the case with a length shorter than the chamber. Problem, I can not walk into a store that sells new, over the counter, factory loaded ammo and expect the bolt to close, and I am not the fan of putting a load on the bolt lugs when the bolt closes, I am the only one that does not live in a dirt free environment, my world is full of dirt, grit and grime, some of that stuff listed is abrasive.

F. Guffey
 
Bart B

You stick to shooting guns and I will stick to repairing them. I give up. Guffy, you always go back to the same story about adjusting the dies no matter what the discussion is about. You can not take up the difference in body diameters between the case and the chamber by adjusting the reloading die. Period. Neck sizing is a crude way to do it, but produces it's own problems.
 
Gunplummer, why should we both quit reloading ammo (by me only shooting and you by only repairing and no shooting or reloading; guns) just becasuse I asked you a question you don't know the answer to? Sorry if I asked you about something you don't understand.
 
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just used a utg pull through reamer for my custom 308 mauser. worked simple and easy. backed out to clean probably 15 times. better to be safe than sorry.
 
There was a book written on this, by a guy up in Alaska, if I recall, and is how I picked up a bunch of tips, a few years back. I can not remember the name of the book right off, and I'll have to look for it, but does anyone know the title? I'm pretty sure the author said his shop was in Alaska.

Anyhow, the book takes you through, step by step, the method I learned to use, including setup, mounting the barrel via a 4 jaw chuck with a spider on the back, at the muzzle end, a rotating oil supply collet at the muzzle, the floating chuck for the reamer, and how to use each. The oil supply flushes the chips back toward the cutter, and out the end, but you have to have an oil/coolant pump with enough pressure and flow to do it, and some lathes already have a good one built in.

Update: The title of the book is:

"Advanced Rebarreling Of The Sporting Rifle".
By: Willis H. Fowler Jr.

http://www.amazon.com/Advanced-Rebarreling-Sporting-Willis-Fowler/dp/1439237158/ref=sr_1_1?ie=UTF8&qid=1370796554&sr=8-1&keywords=Advanced+Rebarreling+Of+The+Sporting+Rifle
 
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4V50 Gary,

I would never use a drill, like the guy you speak of, as they always drill oversize, and the bit has no way to truly follow the bore. I'm sure you learned it the way I did, by using a roughing reamer, with a close tolerance pilot, and the same on the finish reamer. I either use Clymer, or Pacific on the reamers, or sets.

How did the barrel turn out, after using a drill? I've heard of others doing this, but I can see a whole mess of problems arising from it.
 
On roughing with a drill:consider the drilled hole will probably not be perfectly co-axial with the bore,and the mouth or entry of the drilled hole will not have a perfect edge condition.

The reamer pilot is unsupported as the the reamer begins to cut.

The outside flutes catch the edges of the drilled hole and start.Some deflection will likely occur.The reamer body will create and follow its own axis.

As progress is made,eventually the reamer pilot will get to the bore.Suppose there is .0002 clearance for the pilot to ride the lands,but the drll helped the reamer find an axis .0015 off the bore axis.Suddenly the bore is forcing the reamer sideways .0014.

The pilot,especially if it is solid,will damage the lands.

Now,the flutes on one side of the reamer are suddenly forced sideways .0014,digging in a.0014 thick chip.Will the edge cave off the flute?Maybe.Now the chamber is an oversize oval with rattle room to chatter.

Let me guess,now its time to wrap abrasive cloth on a split stick and "polish" the chamber.
 
My 'smith dialed in barrels held in a 4-jaw chuck with a gauge pin of exact bore diameter to get the breech end of the rifled blank turning on center. Then he started in the piloted reamer that well aligned it with the hole in the barrel. Just like gun drilling a solid blank; the cutting tool tends to center about the rotation axis and makes holes very straight.

Muzzles were faced off a similar way after dialing in the muzzle end with a similar gauging pin. A small amount of outside barrel diameter was turned off so it would put the bore centered in a chuck that held the muzzle turning on bore center while the 11 degree recessed muzzle face was made then a fine abrasive charged lapping ball was used to put the angled crown on the rifling out to a few thousandths past groove diameter.

Some 'smiths have checked barrel chambers for roundness that when used, shot sub 1/4" 100 yard groups all day long with good bullets. Even those chambers were, just like sized case bodys, were not perfectly round.

I think it's the barrel's metalurgy makup that causes all these dimensional irregularities. As the tool's cutting edge removes metal, the resistance it has to being machined causes the tool to move a bit. Another example is rifling twists taking a jump in twist rate in button rifled barrels; the button didn't maintain the same point and it twisted too much or too little to keep the rifling angle exactly the same from breech to muzzle. There's folks that'll measure your barrel for rifling twist irregularaties.
 
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I use pin gages and a 4-jaw at the chuck,and also do the same at the other end of the barrel with a spider.
I crown the same way,generally 11 deg,then I put a center drill in the tool holder and use it like a boring bar to just cut a small corner break ,maybe .002 at the grooves.
 
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