Lapping Barrels and general barrel questions for Bill Calfee

Bill,

Do you think Muller barrels are harder than Ratchets to find the best place to crown and chamber? Should Muller barrels be left as long as possible to gain the most accuracy vs Ratchets where inexperienced smiths just backs up to the 22-24" length and chambers, etc?

I know you've been lapping for a long time. I know you are an expert at lapping barrels. So if we rated you a 10 how would you rate Tvolstad (says he laps), Muller (Seen pictures of him lapping), and the general Shilen lap respectively?

To go one step further, if you had one of each of the above just handed to you could you tell who lapped the barrel? I'm pretty sure you could identify your own. What about the other three?

Friend wsmallwood

wsmallwood said:

Bill,

....1...Do you think Muller barrels are harder than Ratchets to find the best place to crown and chamber? Should Muller barrels be left as long as possible to gain the most accuracy vs Ratchets where inexperienced smiths just backs up to the 22-24" length and chambers, etc?

....2...I know you've been lapping for a long time. I know you are an expert at lapping barrels. So if we rated you a 10 how would you rate Tvolstad (says he laps), Muller (Seen pictures of him lapping), and the general Shilen lap respectively?

....3.....To go one step further, if you had one of each of the above just handed to you could you tell who lapped the barrel? I'm pretty sure you could identify your own. What about the other three?

Click to expand...

__________________________


Friend wsmallwood:


Your question #1


A properly produced Muller is no more sensitive to where the chamber and crown are located than is a properly produced Shilen, and vice-versa.


Likewise, there is no difference in the accuracy potential between a Muller and Shilen due to length.



Your question #2


Taper lapping a rimfire bore, properly, is performed by artists.


I titled my book "The ART of Rimfire Accuracy".


I titled it such, because producing rimfire accuracy is Art in its purest form, and one of the most critical aspects of producing rimfire accuracy is how rimfire bores are lapped, which if done properly, can only be performed by dedicated, artistic artisans.


I'll pass on who I believe to be the finest artist, today, when it comes to taper lapping a rimfire bore properly.



Your question #3


No, I would not be able to determine who lapped a bore by just inspecting it.


It is very easy to determine if a bore was properly taper lapped, no matter who lapped it.




Wally, during the heyday of properly taper lapped rimfire barrels, say from late 2006 to maybe 2013 or early 2014, there was a far greater percentage of properly taper lapped barrels than there is today.


Of the last couple dozen barrels I've evaluated over the last three or four years, or so, I can only remember two that were taper lapped like those from the heyday of taper lapped barrels.


Your friend, Bill Calfee


__________________________


PS:


Wally, although I can't tell who lapped a bore by examining it, I can pretty much tell how they went about doing the lapping.


An example:


I push a slug through the bore of a new blank from the breech end, stopping it at the muzzle.


I turn the blank around in my vise and push the slug back to the breech end, "feeling" of how it's tapered.


I find that this new blank has an excellent "feeling" taper, with the slug almost falling out of the breech end with very little pressure on the slugging rod.


Then I measure the groove diameter at the breech end and the muzzle end, to determine exactly how much taper this bore actually has.


And I find that the groove diameter at the muzzle and breech measure almost the same.


Not near as much difference in the groove diameter measurements to justify how nice the taper in the bore "felt".



For anyone here at CYA, what does this tell me about how this blank was lapped?

Bill,

I'm not astute enough to tell you how it was lapped. But I do recall you saying once that taper lapping is to maintain contact and that if a blank will maintain consistent contact with the bullet it does not need to lapped. Upon which you showed ma a barrel and had me push the slug through that felt great to me. You said it did not need lapping. Best I recall it was a good barrel.

WS

Bill or others.

Have you ever had possibility to slug barrel lapping made by Sunnen honing machine?

www.sunnen.com/gun_barrel_honing

We know that humans hand feels VERY little differences on measurements.

Lapping is so hard work that everybody hopes that someday Sunnen or some other company find the way make the same than human hand.

Maybe you must sell your lapping "hand moving " data to Sunnen-.

BR, Timo

Friends wsmallwood and Timo

Friends wsmallwood and Timo


Friend Wally:


If the bore/grooves were absolutely perfect from one end of the barrel to the other, that barrel would shoot equally as well as a properly taper lapped bore.


My problem is, that I'm not well enough acquainted with The Almighty so as to get Him to make me some.


Because no one here on Earth can do it......(except by pure accident)


Therefore, we taper lap our bores.


____________________


Friend Timo:


Maybe someday, someone will figure out how to make either absolutely perfect bore/groove barrels, or, devise a computer controlled automated taper lapping machine that can duplicate the "feel" of an artistic human being.


I watched the movie on the Sunnen web site you posted.


Here's a quote from that web site that is kinda interesting.......I highlighted a couple of places of interest.


The quote:

"Honing is fast, accurate and can be automated. It's surface quality and geometry can duplicate lapping, except for the longitudinal lines of the lapped finish.

Honing is one of the processes used to make affordable, mass produced barrels that regularly hit MOA accuracies."






Friend Timo, waxed, lead bullet rimfire accuracy will always be produced, at its highest level, by artistic artisans, most likely.



Your friend, Bill Calfee

Bill Calfee said:

__________________________


Friend wsmallwood:


Your question #1


A properly produced Muller is no more sensitive to where the chamber and crown are located than is a properly produced Shilen, and vice-versa.


Likewise, there is no difference in the accuracy potential between a Muller and Shilen due to length.



Your question #2


Taper lapping a rimfire bore, properly, is performed by artists.


I titled my book "The ART of Rimfire Accuracy".


I titled it such, because producing rimfire accuracy is Art in its purest form, and one of the most critical aspects of producing rimfire accuracy is how rimfire bores are lapped, which if done properly, can only be performed by dedicated, artistic artisans.


I'll pass on who I believe to be the finest artist, today, when it comes to taper lapping a rimfire bore properly.



Your question #3


No, I would not be able to determine who lapped a bore by just inspecting it.


It is very easy to determine if a bore was properly taper lapped, no matter who lapped it.




Wally, during the heyday of properly taper lapped rimfire barrels, say from late 2006 to maybe 2013 or early 2014, there was a far greater percentage of properly taper lapped barrels than there is today.


Of the last couple dozen barrels I've evaluated over the last three or four years, or so, I can only remember two that were taper lapped like those from the heyday of taper lapped barrels.


Your friend, Bill Calfee


__________________________


PS:


Wally, although I can't tell who lapped a bore by examining it, I can pretty much tell how they went about doing the lapping.


An example:


I push a slug through the bore of a new blank from the breech end, stopping it at the muzzle.


I turn the blank around in my vise and push the slug back to the breech end, "feeling" of how it's tapered.


I find that this new blank has an excellent "feeling" taper, with the slug almost falling out of the breech end with very little pressure on the slugging rod.


Then I measure the groove diameter at the breech end and the muzzle end, to determine exactly how much taper this bore actually has.


And I find that the groove diameter at the muzzle and breech measure almost the same.


Not near as much difference in the groove diameter measurements to justify how nice the taper in the bore "felt".



For anyone here at CYA, what does this tell me about how this blank was lapped?

Click to expand...

Howdy Bill,
First, my excuse if I'm wrong. Two weeks out from surgery and it still feels like I've had a chainsaw taken to my back, so any lack of clarity in thought or just plain stupidity (especially plain stupidity!) I'm blaming on that, no matter what. However...........


It sorta looks like targets were set for the breech and muzzle and the taper was done trying to meet those targets. I don't know whether or not that approach, if that is what it is, would allow complete fluidity from breech to muzzle. I can understand setting a target for the muzzle, don't know about setting an absolute target for the breech. Seems to me the fluidity of taper is more critical than an absolute target at the breach, within reason on the breach target size, if indeed that's what it is.

Is there perhaps a small sorta lengthy constriction somewhere after the breach that could affect the feel if targets were set for both breach and muzzle? If the measurements of breech and muzzle slugs don't seem to match up to the feel, I can't think of anything else other than the fluidity between them being just a liiiiitle bit off.

Well, crud, I just re-read that last couple of sentences and I'm not wording it like I want and stuff hurts more the longer I sit here and makes it harder to think. How about this......when you ran the slug from muzzle to breech..........did you find a spot transitioning from the bore to the alleged breech target I'm trying to describe that was not quite as fluid, that allowed the slug to come out with the slightest pressure of the rod, as you described? If that's what happened, could you feel a difference on the lapping at that point? If there was an alleged breech target, did tapering right after that target not come out as fluid as it perhaps would have if there was not an absolute target, if there was one, at the breech? Would setting a specific breech target affect the fluidity of tapering after the breech? I'm still not wording this like I want it to come out. Man alive, I hope you can make some sense of this.

I don't even know if I've made sense on this, but I'm going to post it as is because I just have to get up and move. If I've said something stupid or something useful, let me know.

When I heal up, Good Lord willing I will be able to do things I've not been able to do in years. I intend to LEARN MORE more about this.

Any schooling you care to toss out on what I've said is appreciated.

Take care,

Greg

Sunnen Honing machine

Hi Bill

I thought the Sunnen machine was a good idea to prepare the bore after it was reamed and before pulling a button.
Giving the bore a better surface finish and more important sizing it.
Hand lapping still happens after the button is pulled.

I don't know if this already happens but I can imaging with the Sunnen machine you could program a slight taper in the bore before the button is pulled.
This may lead to a slight pre-lapping taper in the bore then to be finished off by hand.

Regards
Graham

: I push a slug through the bore of a new blank from the breech end said:

Not near as much difference in the groove diameter measurements to justify how nice the taper in the bore "felt".[/SIZE]



For anyone here at CYA, what does this tell me about how this blank was lapped?[/COLOR][/SIZE][/B]

Click to expand...

Mr. Calfee,

Would this barrel example show signs of the breech end being washed out??

Tad

Friend Tad E

Tad Earhart said:

Mr. Calfee,

Would this barrel example show signs of the breech end being washed out??

Tad

Click to expand...

_______________________


Friend Tad E:


You got it.


Tad, I got up to pee-pee and turned on my machine and saw your post, along with Greg's and Graham's.......


We'll discuss this more tomorrow....in detail.


Your friend, BC

"Properly" taper lapping a rimfire barrel

"Properly" taper lapping a rimfire barrel


Friends 404tbang and Deveng:


Bang, the ole Hawk calls you "Bang".

Hang in there with that back..........take your time, and get it right, cause you need to sit behind a Class A pistol, just one time.



Friend Deveng:


That was an interesting video.




____________________________________________



"Properly" taper lapping a rimfire barrel:


I'm sorry to say this CYA friends, but, that ART was lost sometime in late 13' or early 14'.


I've seen so many barrels with the breech end washed out since then........



BC




_____________________________


PS:


Do we continue discussing this subject, knowing full well we may offend some folks?

Yes. Sunnen honing is used after reaming,not (yet) to taper lapping.Or if they can make slight taper after reaming honing, I dont know.
Or is there any sense to make so because button makes inside measurements the same if barrel blank has same outside dimension from breech to muzzle.

I dont know how much Bill or others has played with Pac Nor rimfire barrels last few years when they bought Sunnen honing machine.

Thats why I asked.

www.sunnen.com/NewsDetails.aspx?NewsID=108

BR, Timo

Friend timo

Timo said:

Yes. Sunnen honing is used after reaming,not (yet) to taper lapping.Or if they can make slight taper after reaming honing, I dont know.
Or is there any sense to make so because button makes inside measurements the same if barrel blank has same outside dimension from breech to muzzle.

I dont know how much Bill or others has played with Pac Nor rimfire barrels last few years when they bought Sunnen honing machine.

Thats why I asked.

www.sunnen.com/NewsDetails.aspx?NewsID=108

BR, Timo

Click to expand...

_________________________


Friend Timo:


I'll say this: That article is a very accurate description of the job of lapping barrels.


Here's the first paragraph quoted:


( I like the use of the word "art" in the first sentence, which is exactly what proper taper lapping is)



The quote:

(I highlighted the "watershed statement"of this quote in bright orange.)


"Manufacturing precision rifle barrels has always been something of an art that involves hand lapping of the bore surface twice, before and after the rifling profile is cut or swaged in by a rifling button. In fact, a bright, hand-lapped bore is considered one of the hallmarks of a precision rifle barrel, despite the inherent variations from manual work done by people who get bored and tired from the monotonous chore"


__________________________


Friend Timo, I know nothing about these barrels, today.


Years ago the ones I knew of weren't setting any rimfire accuracy records.


But, things may have changed since then.




In my past conversations with Dan Muller, he stressed the importance of having the bored, reamed and lapped hole perfect, before the button was pulled through.


______________________



Now, how to go about producing the number of "properly" taper lapped barrels, like were turned out back in the heyday of taper lapped barrels?


Your friend, BC

Friend JH

Jerry Halcomb said:

Years ago the ones I knew of weren't setting any rimfire accuracy records.

Bill
I do believe that Norm Diedrich’s winning record setting rifle in the early days of ARA had a PAC Nor barrel. This is the way I remember it.
Things were not as well publicized in those days.

Jerry Halcomb

Click to expand...

__________________


Friend JH:


Thanks for the info....


CYA friends, Norm fired the first 2400 ARA score in history.


A week later at Miami R&P in Ohio, Steve Turner kicked out the second 2400 ARA card ever fired......


Guess what type of gun Steve was shooting.......


Your friend, BC

Bill!

Have you measured taper lapped barrels lands width from breech and muzzle?

Do we have little narrower lands on the breech?

If so,this is good thing to lead bullet when pressure behind bullet is going down after 15 inches or so.Also smokeless powder burns always better if we can get more work to bullet and pressure is higher.

Can somebody make barrels where lands are wider on muzzle than breech???-.

BR, Timo

Friend Timo

Timo said:

Bill!

Have you measured taper lapped barrels lands width from breech and muzzle?

Do we have little narrower lands on the breech?

If so,this is good thing to lead bullet when pressure behind bullet is going down after 15 inches or so.Also smokeless powder burns always better if we can get more work to bullet and pressure is higher.

Can somebody make barrels where lands are wider on muzzle than breech???-.

BR, Timo

Click to expand...

___________________________



Friend Timo:


Yes.



The process of taper lapping requires more lapping at the breech end than at the muzzle.


The lands turn the lap, so it would seem natural that the land width at the breech would be narrower that at the muzzle.


And on what I call "washed out" breech end barrels, the lands do get narrower at the breech.


But, is this really a good thing?



I don't believe it is, and here's why:



When a .224" diameter bullet enters a .222" diameter bore, the lead has to go somewhere......and that somewhere is in elongation of the bullet.


In a taper lapped bore, without any land width change, there is a slight continual elongation of the bullet as it travels down the bore.


We accept this, and live with it, so we can guarantee that the last thing the bullet sees as it exits the muzzle, is the tightest, and roundest, place in the bore.



But, when the bullet has to deal with the elongation caused by both the taper in the bore, and, the land width change, we no longer have just a slight elongation to deal with, we now have a major elongation to deal with, with regards to the ultimate accuracy potential of the bore.




Here's what I want in a match rimfire bore, in order of preference:



1. My first choice would be perfectly uniform bore/grooves for the entire length of the bore.

No taper, just a "perfectly" uniform bore from breech to muzzle.


I have absolutely no doubt that a barrel like this will provide the ultimate in rimfire accuracy potential.



2. My second choice, and the one that's most practical, since perfectly uniform bores are almost impossible to achieve, is a very uniformly tapered bore from breech to muzzle, with the integrity of the lands unchanged for the entire length of the bore.


.0002" taper in a 26" bore is all that is needed.


Actually, for the elongation change issue I spoke of, .0002" is all we ever want so as to keep the elongation change to the bare minimum.



Friend Timo, I base what I've stated above on experience.


My most successful taper lapped bores have the integrity of the lands unchanged from chamber to crown, and are in the .0002" range of taper.


In other words, these bores are not "washed out" at the breech, and the land width is uniform their entire length.


There's only one "fool proof" way to achieve this kind of bore:


The "art" of lap bumping must be incorporated in the taper lapping process.


Your friend, Bill Calfee


_________________________________



PS:


Friend Timo, if one could someway guarantee that every lap cast had the identical texture, then one could achieve the kind of bore I've described, without bumping the lap, simply by casting maybe 10 or 12 laps during the taper lapping process.


I've lapped bores since the 80's, and I can not cast perfectly identical textured laps one after another.


If I needed 10 laps, I'd probably have to cast twice that many to come up with 8 or 10 with identical texture.


So I learned how to bump my laps, and even at that I'll stick one every once in a while.....


And the only way to remove a stuck lap is to melt it out.

Yes.It is very hard to get identical texture to laps.We were teached on "lapping course" that warm barrel about 120 C degrees (248 F) before put smelt lead in.
I dont know if there are different temperatures depending how much antimony and tin is in lead???

Shultz & Larsen (Denmark) was known very good lapped barrels few tens years ago.I dont know how it is today.

They use longer laps than it is "normal". (Must be VERY STRONG people)

Maybe in this video you can see on time 2,36--> how they can make so long laps.They put smelt lead to barrel with pump.Looks easy and safe way...

If I see right here is going lapping after reaming.Not after rifling.

www.youtube.com/watch?v=Hecf_z0lFWQ

BR, Timo