roughing reamer?

T

tiny68

Member
I am thinking about buying my own reamer for the 30BR. I have always rented reamers before. My smith doesn't carry any. Talked with Dave Kiff (sp?) and PGT. He said I would need a rough in reamer to go with the finish reamer. My smith says he always step drills and then just goes with the finish reamer.

So what do you pros use on BR barrels?

tiny
 
I started out many years ago and could not afford to buy a roughing reamer so I got in the habit of using drills...

In benchrest chambers I still use drills and then step boring (indicated on the throat area), before using the finish reamer.

Many smiths will use drills and a finish reamer...
 
Tiny68,

Yes many of the pros absolutely DO pre-drill and/or pre-bore (probably most of them) but there's another reason to get a roughing reamer, a GOOD reason.

First of all, understand that it's in no way "rough", it's just smaller than the finish reamer......it's not even cheaper nor poorly finished nor nuttin', it's exactly the same quality as the chambering reamer only smaller.

And you can use it to make your fitted sizing die.

I order mine to be exactly .002 smaller in diameter than my chamber reamer but several folks more experienced than me use .002 or .003 at the shoulder and .0025 up to .004 the base, just above the web. In other words they set the taper of the die reamer to be subtly different than the chamber, not parallel the sides.


I've tried the above numbers and a bunch that're weirder and MY PERSONAL CHOICE is to size the finish reamer .006 bigger than the chosen brass at the butt and minimum taper on the reamer, like for my BR cases I like only .012 total taper in the body. I run .012 to .015 total body taper and have two reamers with only .010 taper and no observed ill effects. I don't know the logical limit to "minimum body taper" but have found .012-.013 taper to be very nice numbers. I also know of some folks running .004 of squish at the shoulder and slightly less at the web, reverse taper to the "norm". I've never tried this.

For ME, the "roughing reamer" or actually the FL Die Reamer is then sized .002 smaller, shoulder and web for PPC/BR/47L/308 cases.

I know why some of he others do it differently and I know why I do it the way I do.

If you get both reamers and use the one for your die, the cost of the second one can be used to offset the cost of a sizing die.


There is currently a bit of a problem with this method........ finding a 'smith who'll cut your die and have it hardened may take some time, if he'll do it at all.

Jim Carstensen of JLC will make you a hardened sizer from your actual chamber reamer and shrink it to fit. AFAIK only he does this.

Neil Jones will make you a Cadillac fitted die from the dimensions of your supplied brass and the Harrell's will make you one cheaper. But the Harrell bro's only do BR/PPC and the new 47L case. Neil does any chambering.

Another option which I'm currently in the process of trying is to have Lonnie Hummell of Hornady make a hardened sizer die....... going this route would eliminate the need for a roughing reamer.

BTW, I've got one HS steel 6BR reamer which has cut 5 chambers all by itself, no rougher, no pre-boring... and the reamer still cuts a good chamber. I don't know how many chambers a reamer will cut all by itself.

I do silly stuff like asking for a different diameter pilot on each reamer I order. Since the reamer comes with a pilot, I've now got 7 different 6mm pilots with no appreciable cost.

I'm a bit of a tightwad :)

For your situation I'd probably just order a finish reamer ONLY and have the Bro's Harrell work their magic on your 30BR die. Dave will send reamers without a rougher to go along with it. This would seem to be the cheapest route based on your supplied information.

If you already own a 30BR you can send Kiff some samples of your fired brass and he can make you a finish reamer that matches your existing stuff...... Dave's a wiz this way.


hth


al
 
tiny68 said:
PGT . . . said I would need a rough in reamer to go with the finish reamer. My smith says he always step drills and then just goes with the finish reamer.
Click to expand...
You can only cut so many chambers before a reamer needs to be resharpened. You can only have it sharpened so many times before it gets measurably smaller. If this is your finish reamer, you'll then need a new one. But if the "got a bit smaller" reamer is the rougher, it doesn't matter -- unless, like alinwa, you are using it for dies. Consider yourself dissed, Al.

OK, all this might have some importance for a pro, who (hopefully for his retirement fund) cuts a lot of chambers. Except as Dennis pointed out, a rougher costs just as much, and there are advantages to the drill & bore technique anyway. If you are just chambering a bunch of rifles where the last bit of accuracy doesn't matter so much, a rougher might make business sense, or might not -- whatever technique gives the pro the shortest time/least cost & a satisfactory result is the goal.

How long a reamer will last before needing resharpening seems to depend on several factors--cooling/flushing reportedly the biggest. And resharpening several times is no problem, either.

For personal use (which is my situation), I can't see a need for a rougher, just drill & bore like the pros. If you're going to get an FL sizing reamer, I sure wouldn't wear it out roughing out chambers. And I don't like Al's numbers, and piloting needed for dies is different than in barrel, and ... and ...

Having said all that, there are a few people doing only their own work who just want to kiss the chamber with their finish reamer -- consistency over time, I guess -- and so use a rougher after boring. I haven't noticed them winning any more matches, though.

FWIW
 
I don't want rehash some of this stuff but would like to inject this idea.

What is the single most important cutting edge on a reamer?

It's not the body.
It's not the shoulder area.
It's not the neck.

It's the lead angle on the throat.

That is the only part of the reamer that really matters. Everyone can say they are still cutting chambers with a good finish but who cares if the brass has a shiny ring around it or you have an ugly looking shoulder. The throat has to cut as cleanly as possible. Unfortunately that is the part of the reamer that cuts more than the other surfaces, thus it gets dull faster. All you guys that have more than 5 chambers on your reamers look closely, look very closely at your throat area. You'll see the edge starting to break down. When that happens it will start to plow metal instead of cutting/shearing metal.

Now what do you do about it. I keep an eye on my reamers and when the throat is breaking down I send them back and have just enough taken off that if you were looking at them on an optical comparator, the cutting edge will look straight again instead of scalloped. Usually .004" or less.

How long will it take to break a barrel in if you have rolled metal from the land into the groove? That happens to some extent in every chamber. That's why we have a break-in process to smooth up the throat. I do something to every barrel that leaves here now. I've tuned rifles up in less than 30 rounds because no break-in process was needed.

I've seen barrels where half the land was pushed over and sitting in the groove. I'll bet those were fun to tune up.

Dave
 
Dave

How about my 300wsm chamber job? -- to fit a new Berger thick jacket 190, please. :confused: Overbore <gca747@bellsouth.net>
 
Some idea ...... my gunsmith uses a older reamer to start with, then switches to a newer reamer to finish .
Get a couple chambers cut with one and then buy a second and use it to finish the last .100" or so.


Dave --

You wrote:
"I do something to every barrel that leaves here now"
I can speculate of course, but you have me very curious and would like to hear more....


Happy Shooting
Donovan Moran
 
Donavan

There are some things my customers don't need to know about. What I do is pretty aggressive so I can't recommend it to everyone because there is always one person who thinks if a little bit is good then a whole bunch must be better. Let's say there are no more burrs in the throat area.

Dave
 
Jeepers Charles,

I'm not sure what to say.........but it's dis'd Mr Editor :D

I'm not advocating using the "roughing reamer" for cutting the chamber A'tall..... I use them to make my dies.

Yes the pilot will be different for reaming a die. tiny68, your gunsmith will have the appropriate size for your choice of blank, or his own. The pilots on the reamers are for barrels.

I'm not advocating cutting chambers using only the finisher........ Mr tiny68 sounds like a shooter/owner, not a guy looking to produce chambers in a shop. His die will probably last a long time FOR HIM. To illustrate this I chose to mention that I've had 5 chambers cut with a 6BR HS steel reamer, my first one. I didn't know better.

Which numbers dincha' like?? The sizing numbers or the fat butt? :)


Dave T,


That's good info right thar! ;)

I think I might go down and drive a slug back into a couple new chambers, check for burrs........


Now, when you have your reamer throats freshened do you have the whole reamer dropped back? Or do you just shorten the freebore? I'm guessing that my "good reamer after 5 hog-jobs" is pretty well SMOKED the throat!! Luckily I recut my own throats using Kiff's hand throater but yowsahhhh, you set me back there.....


Thank you


al


tiny68, this's why this forum ROCKS!!!
 
Al, just a bit of nomenclatura . . .

A *roughing reamer* or *rougher* is used to cut the chamber to close to its finished dimensions. Many are carbide.

A *resize reamer* or *FL reamer* is used to make a full-length sizing die.

I know people who have three for each chambering, finish, rougher, and FL-resize.

It sounds to me that tiny68 wants his own reamer just for consistency from barrel to barrel, but Dave Tooley will fit his barrels. In that case, I'd order exactly what Dave Tooley wants.

As to Dave's remark about wear on the leade, I've long thought about getting any new reamers with no leade & cutting the throat with a throating reamer. Of course, this just changes what wears fastest on the chambering reamer, but neither the neck nor step-down seems as critical as the throat . . .
 
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Al

I just have the throat shortened. .003-.005" isn't much in the whole scheme of things. I think you could resharpen the throat probably twice before you had to work on the body of the reamer. Unless you do it for a living and chamber a lot of barrels you would have moved on to another caliber or a higher place by that time.

Dave
 
Reamer Wear

Dave has touched on a critical point. I use only finishing reamers (no roughers), and do my chambers in a high presure flush system. I treat my reamers with absolute TLC. I have all my personal reamers cut with .020-.040freebore and use a throating reamer to finish the chamber. A piloted finishing reamer cost to my door $152.00. A piloted throating reamer cost $69.00 to my door. I can give my customer a custom chamber to match his bullet seating.

Years back when I chambered by drilling, boring, reaming and cleaning at very low speed my reamers showed wear immediately upon use. Since I switched to a flush system (30 to 125 psi) and ream at a constant higher speed my cuts are made with a lighter feed. The smaller chips flush out under about 30 psi. Approximately every .100 I back the reamer out with the barrel turning and run the presure up to 75-125 psi. This allows for the larger chips to also flush. Before I finish the last .100, I remove the reamer and clean and inspect all the leading edges. The complete the chamber.

Reamers of 50 years ago and older had two cutting surfaces and were called half reamers. Todays reamers have 6 and 8 cutting surfaces, and one can get them in straight or heilical cut. They are made of tool steel and or carbide. These materials are significantly harder than the material they are cutting. Sharp tooling run at the cutting speeds they are made to cut at make chambering a more precise process. Running a reamer slow means the feed needs to be heavier this inducess heat, chatter, and stress in the metal to things a barrel does not need. Barrels cut with a flush system never get warmer than room temperature. Most of my work is on stainless steel and we all know stainless steel will work hardens in a second if it gets any heat in it.

When in machining school we were taught to run reamers at the slowest possible speed we kept them well coated with cutting oil. Chamber reamers are somewhat different than hole/bore reamers.

With hole/bore reamers the leading edge and OD do all the cutting. The chamber reamer is cutting on all sides, it is drilling/boring in the front and reaming on the sides. The smaller surfaces are going to take the most abuse. Again lighter feeds and positive lubrication/cooling/flushing only makes sense. When I talked with the engineers with Rustlic about my flush system coolant lubricant they recomended an extreme pressure coolant/lubricant. I use Rustlic 255R. My reamers are lasting literally 100s of chambers between regrinds where before I had them reground about every 10-15 chamber or as needed. With a little experience you can feel the difference in a sharp reamer and a dull one.
Reaming time takes longer and the tool wear become exponential.

This is my take on this subject.

Rustystud
 
Charles E said:
It sounds to me that tiny68 wants his own reamer just for consistency from barrel to barrel, but Dave Tooley will fit his barrels. In that case, I'd order exactly what Dave Tooley wants.
Click to expand...

I certainly don't have the skills to run a lathe more less chamber a barrel. Dave has blue-printed and barreled M700 for me recently using his reamer.

I have become a big fan of the Savage actions. I have one the target actions that has been true and timed by Fred at SSS. It know it is not a custom, but it is pretty smooth on the bolt lift and comparable to the other customs actions I have cycled (which have been few). I have been buying blanks and having my gunsmith (not Dave) thread and chamber. I have a collection of barrels for my couple of actions.

I certainly would like to have a barrel chambered and threaded by a pro like David for my Savage for a 30BR as a low cost BR gun. Most of the website for the name gunsmiths state they either work on Rem M700s or customs and not other types of actions.

But you are correct, I want my own reamer for barrel to barrel consistency and to avoid the rental fee if I decide to have another blank chambered by my current smith.

Really considering just buying a pre-fit directly from Shilen or PacNor. They have the 30BR Robinett (sp?) reamer that I would like to used. I asked about the quality of Shilen's chambering versus having a true BR gunsmith doing the chambering and threading on this forum a while back and got very mixed opinions. I have heard of a couple of problems with the chamber jobs on Shilen pre-fits but Shilen fixed them.

Thanks for everyone's input. I am trying to learn a little as I go.

tiny
 
Lathe speeds

Ken:

My sppeds vary depending on the caiber and chamber. The small stuff is run slower usually 75-125 rpms, The larger cases 308 and up I run 175- 225. I have run reamers as high as 400 rpm. I don't dwell on speed in rpms. I ream by feel. Reamers need to cut and not grind out the metal. My reamers make ships that are just thicker than typing paper.
Rustystud
 
hear more

dmoran65 said:
Some idea ......
Dave --

You wrote:
"I do something to every barrel that leaves here now"
I can speculate of course, but you have me very curious and would like to hear more....


Happy Shooting
Donovan Moran
Click to expand...
,,,,,,,,,,,,,,,,,,,

Donovan

You precision imbecile, you have absolutely no idea and know absolutely nothing.,,,, Because if you did, you would know that a reamer is a "finishing tool". Which means that it makes the final cut/dimension/surface/operation "good enough" so no further finishing is needed or necessary.

If further "pretty aggresive" treatment of the throat is needed after "reaming" it tells me or just about any other (non gunsmith) imbecile like me, that the reamer is as blunt as a garden shovel and no more information is needed.

Donovan you uneducated parrot imbecile keep in mind that this is a Precision Gunsmith Board and we'r suddenly talking about "RAMING after fix" not a reaming finish of free machining 410/416 SS especially known/designed to possess outstanding machinig properties.

Shoot better
Peter
 
The true is that

dmoran65 said:
Some idea ......

Dave --

You wrote:
"I do something to every barrel that leaves here now"
I can speculate of course, but you have me very curious and would like to hear more....


Happy Shooting
Donovan Moran
Click to expand...

My posts are being deleted as quickly as I post them, so lets see,,,,,,,,,,,what one can and/or can't post here.

Donovan

Yourself proclaimed man of knowledge on BR hardware & precision you have absolutely no idea about anything.,,,Because if you had, you would know that a reamer is a "fine finishing tool" and designed to cut/dimensions/surface/shape that's "good enough" so no other operation is needed or necessary.

If any, not just a "pretty aggresive" throat operation is needed after "reaming" it tells me or anybody else with any engineering knowledge that the reamer is as blunt as a garden shovel and no more information is required.

Donovan did you forgot, that this is a Precision Gunsmith Board so why suddenly you'r asking questions about a post "RAMING" remedy, not a precision reaming finish.

Also keep in mind, that most of the BR barrels are 416 SS that's free machining SS and especially designed/known for it's outstanding machining properties..

It tels me (non gunsmith) a lot about your personal engineering "knowledge and precision".

Shoot better
Peter
 
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Rustystud said:
Ken:

Reamers need to cut and not grind out the metal. My reamers make ships that are just thicker than typing paper.
Rustystud
Click to expand...

Mr. Dave Tooley should take a lesson from you. I don't know about the ships?

Con
 
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