reamers (or black magic?)

I'm no machinist but I think running a reamer backwards would dull it in a heartbeat. Just like running a file backwards dulls it because you loose the supporting back to the edge.

Not sure if that makes sense to you but I think you would roll the edge backwards and really muck it up fast.
 
BrentD said:
I'm no machinist but I think running a reamer backwards would dull it in a heartbeat. Just like running a file backwards dulls it because you loose the supporting back to the edge.

Not sure if that makes sense to you but I think you would roll the edge backwards and really muck it up fast.
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Brent your probably correct.... gonna take a "sacrifice" reamer to try it that way.

Up front i don't have a clue what a "hob" should look like or how to use one. Even though Mr. Bill has ever rifle sold he can build till the day he dies -ain't no need to tell a secret.

It is going to be fun to try to figure it out!!! So here we go. Rereading what he already wrote is a big help, "carbon tool steel"...

Firt thought was cut down an allen wrench, then mabe cut down a cold chisel.... then i remembered something from my chevy days. the fule pump push rod has hardned tips.

I dug one up out of my junk and chucked it up, tool steel would not cut it but carbide barley would in small cuts. It was hard for about .400 then fairly easy to cut. Probably some kind of tool steel fusion welded. the outside is hardened to about .040, the inner core is way harder than mild steel and the ends are "tool steel" ish.

The end was cutting to slow and i wrecked a piece of carbide so i used a side grinder while it was spinnin in the lathe to get it down to about .235. Then with a fresh piece of carbide i took it to .223, then polished it down with an Arkansas stone and some 400 grit to .218.

Another clue, Bill said he was asked how to use it. I'm guessing here. At first i thought it would an "exact size" chucked up in the tail stock and run in the bbl, that would be about impossible for me to build with my lathe skills and patience level. I like what Fitch said the other day, "he's got plenty of patience, every bit he was born with, ain't used a drop!" lol -thats me... but i am betting better!

Anyway i got a nice workable piece with a .300 tool steel tip. I thought i was finished but i think i will revise it tomorrow.
"How to use it" sticks in my mind. I'm going to back cut it, make the tool steel end the larger part, oval the tool steel end just a bit like a football.

I'm thinking now spin the bbl in the lathe about 800 rpms then "hand burnish" the chamber and leade with the tool steel "football". Gonna try it by feel, you know sorta like diddling a big tiddy blonde in the back seat! Thats where i am at tonite.

I figure somebody's gotta start somewhere -then we can kinda "B**** it thru"!! One other thing i ordered a camera that should be small enough to look in the chamber -uses a USB cable to hook to the computer so you can view with your monitor. Now if the camera works.......... piece of cake, lol
joe:)

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Joe, I'm watching your progress with much interest and anticipation. I just ordered a Shilen barrel, six weeks 'til I get it. Man, I wish we were neighbors, I was kinda surprised too about the lack of participation by gunsmiths on you other thread. I guess a person gets tired of answering the same questions over and over again, it gets tedious and boring. Thanks, Douglas

Did you get the articles? A friend of mine pulled about fifty bullets and put in a sizing die and gave the bag to me. When I get the new barrel, that's the first thing to do.
 
Douglas said:
Joe, I'm watching your progress with much interest and anticipation. I just ordered a Shilen barrel, six weeks 'til I get it. Man, I wish we were neighbors, I was kinda surprised too about the lack of participation by gunsmiths on you other thread. I guess a person gets tired of answering the same questions over and over again, it gets tedious and boring. Thanks, Douglas

Did you get the articles? A friend of mine pulled about fifty bullets and put in a sizing die and gave the bag to me. When I get the new barrel, that's the first thing to do.
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Douglas i appreciate what the guys do for us rookies! I understand sometimes they are "burnt out" on answering the same question but thats fine, everyone does plenty and i appreciate it!

I feel like i'm "running with scissors" here, lol. Rimfire seems pretty safe to me- I would be going slower with center fire stuff.

I'll get to town in a day or 2 and check the mail box, it's probably there already. I got some stuff to add to my thread and found another mistake i was making! thanks joe:)
 
I've been following this thread with interest, because I have seen a chamber job that definitely had "something" done to the leade. I'm not a rimfire smith, but I've done a few centerfires. Over the years I have looked at the chambers done by quite a few "big name" guys, and payed attention to the leade. Only one smith had burnished the leade once the reamer came out, all the others were left "as is".

"As is" leaves the cutting action radial marks. The barrel is turning, so the cutting action is perpendicular to the direction of bullet travel. In a centerfire, this really isn't much of an issue, becuase the first few rounds fired pretty well burnishes them out. But with a rimfire and the lead bullets, I can certainly see why this would be a long process by firing.

In my mind, to get rid of these reamer marks, it should be done in the same direction as the bullet travel, not the same way as the marks got there in the first place. Also, whatever method is used, it can't change the dimensions left by the reamer, or you would end up with a bigger throat diameter or a longer leade. Unless this is taken into consideration when the reamer is ground, you may end up with varying results from one chamber to the next.

The copied thread written by Calfee tells he used a particular carbon steel "hob". As stated before, a typical lap is a softer metal than what you are lapping, so perhaps the "hob" isn't being used as a lap, per se. He used a lard based fluid, which he has talked about before.

I have thought about a softer material that could be used to smooth out the leade, something such as cratex. If it were turned to the proper diameter and angle of the leade, then it could be used to work out the reamer marks in a fore and aft motion, and it would flex enough where it would self-seat into the leade. Never tried it though.

No answers here, just kicking around a couple thoughts. I think "burnishing" would be a better description than hobbing though.
 
Burnishing tool

The tool your making is a burnisher, it's job isn't to remove metal, it moves and reshapes it. The idea is to flatten the tops of the ridges left by the reamer by pushing them down into valleys leaving a smoother polished surface. Before you spin it up in the lathe try it by hand. You don't want to create a lot of heat or burn anything. The tool should exactly match the taper of the reamer and be hard and highly polished to prevent galling which stainless is very prone to do. You'll be surprised at how easy it is to move the metal around. If you doubt it take a scrap piece of barrel and rub a hard piece of steel against the sharp corner of the muzzle and see how easy it is to put a flat spot on it.

Dennis
 
Hmmm, Just thinking out loud.

I am sure there are a ton of reasons this would not work...but imagine if you could Get a barrel blank, thread it, chamber it, headspace it, then send it back to the barrel maker and have the rifling button pulled through it and lapped as the last process instead of the first. After you get it back, cut it where the muzzle wants to be, then crown it.
Just sort of build them backwards. :eek: A barrel with NO breakin process? Also would the rifling button not align itself with the cut chamber?

Charlie
 
I'm not entirely sure I remember this correctly but I believe Ol' Harry - as in Pope - did that. Might be mistaken but I recall something like that.

Brent
 
Dennis D. said:
The tool your making is a burnisher, it's job isn't to remove metal, it moves and reshapes it. The idea is to flatten the tops of the ridges left by the reamer by pushing them down into valleys leaving a smoother polished surface. Before you spin it up in the lathe try it by hand. You don't want to create a lot of heat or burn anything. The tool should exactly match the taper of the reamer and be hard and highly polished to prevent galling which stainless is very prone to do. You'll be surprised at how easy it is to move the metal around. If you doubt it take a scrap piece of barrel and rub a hard piece of steel against the sharp corner of the muzzle and see how easy it is to put a flat spot on it.

Dennis
Click to expand...

And the clouds parted and the sun appeared.:D
 
I thought that someone once said that a certain someone uses a cordless drill to "hob" his chambers.

I have been polishing and lapping to smooth my leads. Still in the experimental stages of my buildings.
 
Dennis D. said:
The tool your making is a burnisher, it's job isn't to remove metal, it moves and reshapes it. The idea is to flatten the tops of the ridges left by the reamer by pushing them down into valleys leaving a smoother polished surface. Before you spin it up in the lathe try it by hand. You don't want to create a lot of heat or burn anything. The tool should exactly match the taper of the reamer and be hard and highly polished to prevent galling which stainless is very prone to do. You'll be surprised at how easy it is to move the metal around. If you doubt it take a scrap piece of barrel and rub a hard piece of steel against the sharp corner of the muzzle and see how easy it is to put a flat spot on it.

Dennis
Click to expand...

Mr. Dennis is exactly correct!! i tried my "bunisher" at 800 rpm on a barrel scrap... all it did was gall up the metal. Thats what i'm here for to learn!! thanks.

The metal is a lot softer than i was thinking -like extremly soft!! Hand burnishing looks like the ticket. Now i'm wondering just how much damage a cleaning rod can do!! (that will be anotehr thread)

I backed up just a bit, I had ideas but honestly i really didn't know exactly what the leade was or how it looked. I'm not going to be able to polish something i can't understand.

I chambered a barrel and cut it (hacksaw mill) so i could look inside. I have marked what i think must be the leade. I think when you look inside the chamber and see that circle that's the beginning of the leade.

*PLEASE CORRECT ANY MISTAKES* thanks joe :)

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Pilotless Reamer

Joe:
When buying that Pilotless Reamer, did you specify the diameter for the fixed pilot?
 
That's it.

You got it exactly. That's the region you are trying to smooth. Now the better the finish on the reamer the smoother the finish of the leade, provided you clean ALL the chips out between passes and don't let them build up to much. And, as a final thought, if your a professional gunsmith who is required to build a super accurate gun every time right from the first shot this may be a mandatory procedure. Those of us who build our own can just go out and practice a thousand or so rounds in the winter and let the process occur one bullet at a time.

Dennis
 
Fred J said:
Joe:
When buying that Pilotless Reamer, did you specify the diameter for the fixed pilot?
Click to expand...

Mr. Fred i haven't ordered just yet.... I'm just now starting to figure out what to order... I will need several bushings. The tight Lilja bbl will not except a regular "match" reamer, it's going to need a little smaller bushing.

My brain is being crushed with all this input.... look down towards Texas -you see that rising trail of smoke, that's my brain, lol.

Mr. Dennis for Rimfire, may i ask a neighborhood of the speed your run your chamber reamer? I have run low 72 to 200ish rpms and i fell that clunk- clunk-clunk as the reamer cuts. I have tried 400 and the "feel" seems better. I can still feel the clunk clunk but seems smoother.

For reaming i read around on the net and there are a lot of ways, seems a floating reamer driver is recommended. I got a practice bbl i have cut several chambers. The last one i ran at 660 rpms and held the reamer in my hand with a 3/8 wrench. There seems to be a -touch- in there i think i could develop. I can kinda feel around as it is cutting, can't lean it over but just a few thou -if i keep it pretty well dead center seems i can control the feed speed and cutting amt. I am using a very heavy cutting oil -thought maybe the heavy oil will take up space and help keep the reamer centered.

This is just my thought for now.... I'm guessing there are going to be a lot of ways to do chambering.

thanks guys, joe:)
 
Speed & Feed

I tend to run it at around 180 RPM in the lathe and I use a small Starrett tap wrench that's about 3 inches long. The small shafts on the Manson reamers just fit through it and stick out the back end. I then use a coned centerfinder in the tailstock to push the reamer with and hold it between my finger and thumb, if it catches just let it loose, stop the lathe and pull it out, no damage done. The centerfinder lets the little .22 reamer move easily. Lots of heavy cutting oil and remove often (with the lathe stopped) for cleaning and re-oiling. You can also use just hand power and cut a very nice chamber. Put the barrel in a vice, muzzle up and ream the chamber from the ground up, that way gravity doesn't drop the reamer down into the rifling and as you go. The .22 reamer removes so little metal you really don't need the power of the lathe but it takes a little practice to get a feel for. You'll find that different barrel makers barrels cut a little differently, and you'll find that the number of groves makes a differance in how the reamer cuts.

Dennis
 
The chambers i done at slow speed i used a #3 morse to a j3 jacobs adaptor to push with from the tail stock.

I was ready to push at the higher speeds but the reamer is self feeding. I actually have to hold back on the reamer. I guess it's the way the reamer is cut that makes it self feed. joe :)
 
Range

Joe:
The Pilot Bushings are available is a range of sizes. My Freeland came with 5bushings, sized from .212 to .2165. but you can get any range you like. Most barrels I've done, have used the .216 & .2165 bushings.
 
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