Borescope and TC barrels

03 October 2002, 14:50

Several of us at work went together and bought a borescope. Well I finally got to bring it home tonight and have been looking at various barrels.
Quick and dirty veiwing (really dirty thru the scope [Eek!]

)and I noted a very different finish on the barrels. All of the 6.5 TCU barrels looked pretty good on the interior. 30 Herrett were a little rougher and the 35 caliber barrels (357 Max) were rough to very rough with the concentric circles from boring or reaming (IF any reaming was done [Big Grin]

).
The accuracy with my limited testing is not that much different, but the amount of jacket fouling is MUCH higher in the rough barrels.
Even the SHINY 7 mm TCU barrel gets a little rough when viewed with a scope.

And the "leade" on the 45-70 barrel . . . well lets just say the rough edge of the rifling lands were hit with a lick and promise. May have to find a way to work that over a tad before I really test cast bullets. Other leades varied considerable in appearance. Time to do some casts with cerrosafe and compare with what the scope tells me so my mind can comprehend all of the information I am gathering!

Do I fully realize what I'm seeing thru the scope and what it means

. . . HECK NO . . .

it will likely make more and more sense as I look at a lot more barrels!
Browning Buckmark barrel is SURE SMOOTH in comparison to everything else I looked at!
LouisB
Making new discoveries thru technology and having absolutely NO idea what they all mean!

03 October 2002, 15:17

<Fireball>

I just cant wait to hear all the results you come up with using your new TOY! I have long wondered how bad the throats and bores really were on Factory barrels and custom barrels alike.
As far as the OFF center bores?? I just could never swallow the storys of them being off so bad that the RING showing before the rifling was off so bad that it was completly to one side! I know Bellm has Educated us very well....BUT a Bore or chamber so off center as some have discribed seems too far fetched to me.......One could NEVER chamber the round if it was that bad!

Anyway Keep us posted on your findings and maybe how the bad bores/throats accually shoot in real life.

Fireball [Razz]

03 October 2002, 15:46

jsh

Fireball, when and if I ever run across another one that is as bad as I have described in the past, I will send it to you and see what you think. [Wink]

The last 14" 22 Match barrel I bought would not group worth a darn, it had the throat off center of the bore, far from match grade.
I called TC, told them the problem, sent it back for the specific reason of the off center chamber, shazam got a new barrel. No, they don't have any accuracy guarrantee, but the thing was marked "MATCH", they evidently saw the fault or they wouldn't have made it good?
Jeff

03 October 2002, 16:10

<Fireball>

Jeff Not disagreeing with you about OFF CENTER.
But some have said that it was so bad that the neck was compltetly off to one side....NOW a round WILL NOT chamber if it is that bad.
Point being some just get carried away with a little helpfull info.
It will also be very interesting to see which barrels accually SHOOT BAD when a problem is found.
Most of my factory barrels have shot very well.
I have also looked in the throat chamber area of my barrels with scope that a doctor freind of mine has at his office...Yes I have seen rough throats and bores but NOT badly off centered chambers.........atleast not to a HORRIBLE extent.

Fireball [Wink]

03 October 2002, 16:16

<Fireball>

quote:
Originally posted by jsh:
Fireball, when and if I ever run across another one that is as bad as I have described in the past, I will send it to you and see what you think. The last 14" 22 Match barrel I bought would not group worth a darn, it had the throat off center of the bore, far from match grade.
I called TC, told them the problem, sent it back for the specific reason of the off center chamber, shazam got a new barrel. No, they don't have any accuracy guarrantee, but the thing was marked "MATCH", they evidently saw the fault or they wouldn't have made it good?
Jeff

also I am talking about the 30-30 and the other larger bottle neck rounds some have talked about.
I would assume ofcourse a 22lr or straight walled case would still chamber but shoot poorly!

Just see no way a badly off centered 30-30 would chamber.
fireball [Razz]

03 October 2002, 17:00

Sean VHA #60013

quote:
Originally posted by Fireball:
Jeff Not disagreeing with you about OFF CENTER.
But some have said that it was so bad that the neck was compltetly off to one side....NOW a round WILL NOT chamber if it is that bad.
Point being some just get carried away with a little helpfull info.
It will also be very interesting to see which barrels accually SHOOT BAD when a problem is found.
Most of my factory barrels have shot very well.
I have also looked in the throat chamber area of my barrels with scope that a doctor freind of mine has at his office...Yes I have seen rough throats and bores but NOT badly off centered chambers.........atleast not to a HORRIBLE extent.

Fireball

Fireball,

I cannot speak for others, but in my experiences, I had a 9mm 15" Custom Shop barrel that had the kind of throat you are talking about, so bad that the throat was completely off to one side, and it was actually visible with my lighted magnifying glass and a bore light!

I think what you are forgetting in your proposition, that "a round WILL NOT chamber if it is that bad" is to consider how OVERSIZE many T/C throats and chambers are, indeed generally how oversize SAAMI spec reamers are. CASE IN POINT: When I called Bullberry several days ago looking for already made up Contender Target width long forends, the subject of the 17 HMR came up, as I was complimenting Fred on the webpage about the 17 that they had added to their sight. Fred Smith told me then that when he first recieved his 17 HMR reamer, it was a full five and a half thousands too big!

He stated that it was so big that he could not even get the reamer to fit into the holes in the plastic shell holder of a 22mag CCI box.

[in the article he states that he cuts their chambers four thousands smaller for the round and the round still fits, functions, and has no pressure problems: on the phone he gave the full five and a half thousands oversized reamer figure]Go here for his published writeup on the 17HMR:

Bullberry 17HMR Article

This, the condition of severely oversized SAAMI spec chambers due to oversized reamers, is how many such rounds can still chamber even in a throat that is so bad that the throat is completely off to one side as found in my 9mm barrel.

Now when you say that they claim the "NECK" is completely off to one side, are you sure you do not mean "THROAT" ? From what I understand of such things, a reamer is a solid piece from stem to stern, save in the case of some who like Bellm, Jarrett, or some benchrest folks, throat etc as a separate reaming operation....so the neck would hold the same relation to the shoulder of a bottleneck chamber in most all factory throats [not to mention the "wallow" factor which makes such chambers even more oversize] yet the entire chamber be off center to the bore because it was STARTED out that way, thus the off center condition of the "throat."

Is this what you were remembering, or perhaps those who you read that said "NECK" meant "THROAT"? Also, could it be that they have meant "completely off to one side of the BORE" and not off to one side of the CHAMBER when they said "neck"?

[ 10-03-2002, 09:23: Message edited by: Sean VHA #60013 ]

03 October 2002, 17:01

KTS1

Ya I got to look thru a couple of my bbls when I went down to Mikes this spring, it's an eye opener for sure. Specially when it was pointed out that my 'custom bbl.' had a fluted chamber, hmmm...think that'll make it worth more.
Wes

03 October 2002, 18:37

Mike Bellm

quote:
Originally posted by Fireball:
I just cant wait to hear all the results you come up with using your new TOY! I have long wondered how bad the throats and bores really were on Factory barrels and custom barrels alike.
As far as the OFF center bores?? I just could never swallow the storys of them being off so bad that the RING showing before the rifling was off so bad that it was completly to one side! I know Bellm has Educated us very well....BUT a Bore or chamber so off center as some have discribed seems too far fetched to me.......One could NEVER chamber the round if it was that bad!

Anyway Keep us posted on your findings and maybe how the bad bores/throats accually shoot in real life.

Fireball

Lonnie, sure you can chamber a round in one way off center! Their reamers have the throat section on the reamer, and the throat section cuts away clearance for the bullet. That is what a throat is for.

And the degree of off-center.....???? Believe it.

Mike

03 October 2002, 18:41

Mike Bellm

Need I suggest how much fun we can all have now that someone else has a borescope?

You will have to do some mental gymnastics. I have always explained it like this. You have to think inside out, upside down, and backwards. That accomplished, which is no easy task at first, the heavens will open, visions will appear, and you will NEVER look at a barrel again in the same way.

Misery loves company. Welcome to the world of borescopes. Is it a Hawkeye from Gradient Lense Co.? The 17?"

Now, I can't wait to wade through the rest of the posts. Eeeeh Ha!

Mike

03 October 2002, 18:47

Mike Bellm

quote:
Originally posted by Fireball:
Jeff Not disagreeing with you about OFF CENTER.
But some have said that it was so bad that the neck was compltetly off to one side....NOW a round WILL NOT chamber if it is that bad.
Point being some just get carried away with a little helpfull info.
It will also be very interesting to see which barrels accually SHOOT BAD when a problem is found.
Most of my factory barrels have shot very well.
I have also looked in the throat chamber area of my barrels with scope that a doctor freind of mine has at his office...Yes I have seen rough throats and bores but NOT badly off centered chambers.........atleast not to a HORRIBLE extent.

Fireball

Here we go, Lonnie.

Until you learn to read the surface finish inside the barrel, you can actually see the off-center condition better just looking through the barrel with a critical, naked eye. And even after looking through as many barrels as I have, I can sometimes see the off-center condition better without the scope, especially in barrels that have been shot a lot and no longer have the original machining marks inside.

And, once again, ALL of the dimensions for the chamber and throat are on the reamer, which means that the neck portion IS aligned with the chamber body, and the throat, but the whole frapus is not centered with the hole. THAT is the problem..... the problem starts where the bullet first contacts the rifling, which is in front of the last point the reamer cut, like, where the rubber meets the road.

Mike

[ 10-03-2002, 09:52: Message edited by: Mike Bellm ]

04 October 2002, 00:26

TCLouis

Yeah Mike it is the Hawkeye, but not 17". I only wish it was 17". Could see barrel in one pass.
Yes I will have to say, understanding what one sees is going to take some mental gymnastics for a while. scale or magnitude is going to be the hardest . . .may have to mke some standards so I can tell what it really is like!
Mike correct me if I'm wrong but . . .
First you drill a barrel, then ream it to dimension . . . correct?
A person who did work with local muzzleloader "guru" of some import refered to those in the opposite order and I had never heard of drilling something that had been reamed. Of course that would explain some of the roughness I saw in the barrels last night.

To all who are following this . . . all I did was go up and down almost every pistol barrel I had just looking to see what they would look like!
No attempt to see the fine points and as one of the other coowners of the borescope said it will sure teach you about your "barrel cleaning" !
Still no clue why that worthless superblackhawk won't shoot!

Louisb
Owner of technology beyond my understanding!

04 October 2002, 11:13

cas

KTS1.. you got one of them Heckler and Koch style ones.... and you know how much thier guns go for! Bonus!!!

04 October 2002, 11:56

KENTN

Mike Bellm, Here's and idea, many of us would like to know what our chambers and barrels look like. I know you are wanting a camera option for your scope so how about offering a service to shoot our barrels with the camera for a fee.

Do it digital and send it on e-mail or on a disc.
Kind of a before and after if you are doing chamber work.

Heck I would pay $20 for that kind of a look see, still cheaper than me buying a bore scope.

04 October 2002, 14:13

<Fireball>

Well maybe some are off that bad.......BUT Most TC barrels will shoot 1-1.5" groups...and most better.
No argument here But I do not Beleive that a 30-30 with the THROAT completely off to one side will chamber a round.
like I said previously...I understand a straight walled case.

Yes I like my custom barrels MOST of them. But I still have yet to get a Factory barrel that did not shoot well(1" groups..or better) and I cannot say that about EVERY custom barrel I have purchased. I have purchased maybe 20 custom barrels since about 1992 and as I can count off hand over 40 factory barrels. Four of the custom barrels have been Bad shooting...(1.5 groups or worse ) and two in parcticular...Were horror stories...as I spoke with Mike about last year.
As far as TC barrels..They have all shot good...So how many barrels have guys purchased ??

I kinda thought I have purchased enough factory barrels to NOT see a major problem with their accuracy.
Just a wild guess.....but I would say that less than 10% of the factory barrels really shoot badly.

My question is With the bore scope finding the off center throats and all how many of them really shoot bad??

I have a 300 weatherby Mag....shoots well 1" to 1.5 depending on the load..Now this is a $1700.00 rifle.

Got the Terrible Reminmgtons that cost $450.00 that will shoot 1/2" groups.
I just think that while TC barrels may not be PERFECT they shoot extreamly well for a handgun.

As for my custom barrels??? if they dont shoot 3/4" groups and much better for most...they get traded...sold...their is one custom barrel that is in the bottom of Kern river.

I think FAR more pressure should be put on the custom makers than TC.

fireball [Big Grin]

04 October 2002, 14:19

<Fireball>

quote:
Originally posted by Mike Bellm:

quote:
Originally posted by Fireball:
I just cant wait to hear all the results you come up with using your new TOY! I have long wondered how bad the throats and bores really were on Factory barrels and custom barrels alike.
As far as the OFF center bores?? I just could never swallow the storys of them being off so bad that the RING showing before the rifling was off so bad that it was completly to one side! I know Bellm has Educated us very well....BUT a Bore or chamber so off center as some have discribed seems too far fetched to me.......One could NEVER chamber the round if it was that bad!

Anyway Keep us posted on your findings and maybe how the bad bores/throats accually shoot in real life.

Fireball
Lonnie, sure you can chamber a round in one way off center! Their reamers have the throat section on the reamer, and the throat section cuts away clearance for the bullet. That is what a throat is for.

And the degree of off-center.....???? Believe it.

Mike

Yes Mike Understood....But that was a 44 straight walled case.
and it shot twice as good as a Certain custom barrel did with a centered throat.
Never knocked you or your letting us in on the THINGS to look for as I have done myself that last couple years. But some of the stories...TERRIBLE facotry barrel.....after the person has owned it for three years and thought is was accurate shooting 1" groups....now they see a LESS than perfect chamber and it is TRASH???

I expect a perfect chamber/Throat in my BULLBERRY or VV ...but for the price? TC still looks pretty good most of the time......MOST

Fireball
[Wink]

04 October 2002, 16:25

jsh

Fireball, it isn't that when I see a less than "perfect" throat that the barrel is junk, it is the fact that I can see with the "naked" eye the throat is off center that bugs me. There are probably more barrels with bad throats than you will ever hear about, for the simple fact that a 1" group at 100 is pretty darn good factory or custom. Yes, most guys are happy with that, because a handgun cannot be an accurate firearm, or that is what 90% of the public will be led to believe.
What you are forgetting is that the biggest bunch of us here are after one hole groups period. The bunch that frequents this spot and a few others like it are, few and far between.
So not to say that the factory TC barrels won't work, or won't shoot, for the average handgun shooter is a false statment. But the truth is the guys here are above the average handgun shooter, let alone "most" rifle shooters.
So when I take out my factory 7 TCU, and whip the socks off of a couple of friends shooting rifles, it just makes my day. [Big Grin]

Besides when the TC's come out they start putting up rifles anymore, I just don't understand? [Big Grin]

Jeff

05 October 2002, 01:23

LDHunter

Fireball,

Off center throats are one of several problems that can cause a barrel to be "finicky" about bullet selection, powder charges, temperature etc.

A barrel that is well chambered and throated with smooth and well cut lands and grooves and everything being well aligned will tend to be way less finicky which can be a big advantage to both the target shooter and hunter.

Certainly you understand that most people that are on this board are looking for ultimate performance and accuracy from their TC's and don't accept "good" as good enough.....

I personally own several TC barrels and several custom barrels and all are good enough for casual hunting but my "custom" barrels tend to be more accurate, foul less, and are way less finicky. These things are very important to me.

If TC barrels are "good enough" for some people then they will certainly save money....

Only (very) accurate guns are interesting.....

In pursuit of excellence.....

$bob$

05 October 2002, 08:48

Mike Bellm

Lots to cover here....time is short.
REF. Lonnie, KenTx, TC Louis.

Lonnie, visualize that the reamer is relatively rigid and cuts the full profile of the loaded cartridge, including the bullet. 1) There has to be enough clearance on the pilot of the reamer that it will not bind up and gall the tops of the rifling. This introduces room for misalignment. 2) Though made of hardened tool steel, the pilots on reamers are a) smaller in diameter, and b) weakened by the flutes cut in the. Without breaking, they can bend a fair amount when pushed off center from the hole by the much more rigid drill chuck and the quill on the mill or drill press driving it, which itself will always have some runout in it. That is simply the nature of machining.

You can stab a reamer at a hole large enough for the pilot to fit into at a pretty drastic angle or offset and still cut a hole that will readily accept a loaded round. In my earlier days I did it unwittingly quite often, so believe it.

I agree with you totally that 1) inspite of the TC guns' deficiencies which are very, very measureable and identifiable, the accuracy of the guns is legendary compared to rifles, and 2) for most folks this is superlative.

My position is this, enumerating again: 1) There exists a fantastic potential not tapped by the factory, 2)the factory seriously undermines this potential by choices in design, tolerances, and company policy, and 3) they charge a premium price for the product based on successes of a percentage of barrels produced when too large of a percentage of buyers get less than they perceived they would be getting, then 4) inspite of the generous warranty, the company does not have the capability to do more than toss another of the same item of the same design with the same tolerances back to the individual in hopes they will either get lucky or the individual will give up and go away. It just is not right, in my opinion, especially when the information and technology is patently refused by the powers that be in the company who appear to only be concerned about padding their retirements.

Of course they can be generous with their warranty when they charge double what the gun should sell for.

I have a problem with the above. Sorry. Guess it is just my burden to bear, but I do feel shooters have a right to know the facts. If they luck out with factory stuff, great. Or custom for that matter. But when the results are less than expected, there are many explanations for why, and it is my intention to make the information as available and as lucid to as many people as possible. The market place will then respond accordingly, and TC will do what it deems it has to do...... maybe even do me in. Who knows? Stranger things happen for lesser issues.

Ken,
When I first got the borescope, I offered to scope barrels and give a written report of findings at a nominal cost. There were no takers. Guys would graciously accept for free any reports I gave from inspections prior to rechambering work, etc., but no one sent a barrel for evaluation for fee that I can recall. There were some sent, evaluated, and work declined based on findings, but that is all I remember.

I think the borescoping has greater value in educating people.

Visual has greater impact, and like I indicated, you have to go through some real mental gymnastics understanding the holes, shapes, and tolerances.

Case in point, I am making up .30 Bellm cases right now for CNC Cartridge Co. I made matching guages for both my use and theirs. You can look into the forward end of the chamber in the guage and see the end of the case neck and where it comes in relationship to the end of the chamber neck.

Something as simple as case neck end clearance should be really simple to comprehend, shouldn't it? Yet even I understand it better when I look at it, because I can SEE it, and not have to lean on a measurement to try to visualize it. No big deal, really, but the effect is dramatic.

And, btw, you can usually see where the case mouth ends in a chamber and where the chamber neck continues forward. It is evidenced by the ashed/scorched surface in the forward end of the chamber neck. Behind that point the chamber neck is protected from scorching by the case neck.

TC Louis,
Barrels are made this way. Steel usually is sold in 20' bars. It is cut to a length longer than needed for the finished barrel length to allow for flaring at the ends caused as the bore reamers enter or exit the barrel.

The hole is drilled through the bar with a long gundrill, usually about .010" or so undersize, depending on the caliber and how much must be reamed out to get rid of the rough, irregular finish left by the drill.

It is then reamed to final BORE size, which is the diameter ACROSS THE TOPS OF THE RIFLING. Thus to speak of a .224" bore size when talking about a .223 Rem. for example, is technically not right at all. Standard "Bore Size" for .22 centerfires is .219."

Button rifling presses the grooves into the barrel as the smooth carbide "button" is forced through the hole. Whatever finish there is in the reamed hole, which is going around the inside of the hole, is burnished down, but the grooves you see going around the inside of the hole are a result of the reaming process however good or bad it is.

Some rifling buttons do not burnish the tops of the riflings, so you see a more coarse finish on the tops of the lands (riflings) than you do in the grooves. In fact, because you do not get the full perception of depth through the scope, the difference in finish helps you identify whether you are looking at tops of rifling or grooves.

But since the button is pushing a lot more material pressing the grooves in, even if the button has what is called an "ironer" on it, the tops of the riflings are still usually showing more of the original reamed surface than the grooves do.

The short Hawkeye is what, 7" long? That is still enough to fully examine the chamber, throat, and enough of the rifled portion to be extremely helpful.

To all..... have fun. Enjoy.

Mike