"Preferred Barrel Blanks" Vendor -- Opinions

[RegionRat]

Small diameter Sunnen hone tools.

Also used for airgage tooling, bearing reference tooling, hydraulics, precision bores, etc..

A modern tube hone machine with servo controls.

 

[Ray123]

Small diameter Sunnen hone tools.
View attachment 1369050
Also used for airgage tooling, bearing reference tooling, hydraulics, precision bores, etc..

A modern tube hone machine with servo controls.

View attachment 1369051

Yes, times have changed, kind of figured as much the new computer operated honing and lapping machines are capable of air gauging the bore too, or reading pressure to lap or hone, plus faster cutting diamond laps and hones. It was all mechanical back when I started my apprenticeship, a 2 spindle gun drill and a sunnen hone accuracy dependent on the operator. I still would prefer a final finish hand lap, I think... but these new machines are terrific. Benchmark barrels has lapping machine demo...quit doing honeing, lapping, and deep hole drilling in the 1980s, changed to different products, as the market requires, and eventually to CNC mills and lathes, which made huge advances every few years..even had a robot loader on one mill...before retiring.

 

[JSH]

Is there too smooth? Seems like that was hashed a few years ago?

Burrs and high spots I would think would be a top reason for bore treatment?

Pits, myself I never had a huge issue with. Shot a lot of cast bullets in some pitted bores. One place I think carbon had a benefit as a pot hole filler. Though I will say I have had some pits that were a total pita. Buddy fire lapped a great barrel because it fouled in about 40-50 rounds, but it cleaned easy, now it has zero fouling to speak of and shoots just OK.

 

[butchlambert]

I have no experience with cut barrels.
Its not what I was referring to either was it.

I finally got out of bed, actually at 5:45am. Cut rifle barrels are drilled, reamed, and lapped (honed) the same as a button barrel. The laps at the different barrel shops that I have seen are lead cast on a cleaning rod. They are charged with about a 240 grit lapping compound. It follows the lands and grooves and everyting is lapped. Now some have lapped the bore after drilled and reamed. It's direction is through the hole without turning. The ones that are honed with the new Sunnen machine are turning in the bore and not static. Yes, too fine a lap can contribute to copper fouling.

 

[L.Sherm]

I'm well aware of the Button process Butch I've made a few thousand.

 

[butchlambert]

I'm well aware of the Button process Butch I've made a few thousand.

Not saying anything about your experience, just clarifying the different machining operations.

 

[RegionRat]

I finally got out of bed, actually at 5:45am. Cut rifle barrels are drilled, reamed, and lapped (honed) the same as a button barrel. The laps at the different barrel shops that I have seen are lead cast on a cleaning rod. They are charged with about a 240 grit lapping compound. It follows the lands and grooves and everyting is lapped. Now some have lapped the bore after drilled and reamed. It's direction is through the hole without turning. The ones that are honed with the new Sunnen machine are turning in the bore and not static. Yes, too fine a lap can contribute to copper fouling.

The surface finish is controllable to a degree. There is a balancing act with some black magic and voodoo involved, but leaving the right amount of work material allows for each process to create the best surface profile allows you to "design" the surface profile (PRa versus Ra) you want from each step.

The more of something you have to produce, the more likely the economics tilts in your favor in terms of automation and setup/run ratio. I have nothing but sympathy for custom barrel makers and all I can say is I am glad I am retired.

 

[RegionRat]

Is there too smooth? Seems like that was hashed a few years ago?

Burrs and high spots I would think would be a top reason for bore treatment?

Pits, myself I never had a huge issue with. Shot a lot of cast bullets in some pitted bores. One place I think carbon had a benefit as a pot hole filler. Though I will say I have had some pits that were a total pita. Buddy fire lapped a great barrel because it fouled in about 40-50 rounds, but it cleaned easy, now it has zero fouling to speak of and shoots just OK.

This is what I call "luck of the draw".

If you were to look at the steel Jackie is cutting on that shaft support, versus barrel steel, versus air melt bearing steel, and compare it to a VIMVAR grade steel, there is a huge difference in the cost and quality of the cleanliness and grain structure controls.

Some steels have lots of stringers and inclusions and other steels are processed to be nearly perfect, but that adds huge costs.

When cutting or polishing these steels, hitting those carbide clumps or inclusions is just luck of the draw. Making steel that is very clean and nearly perfect can be done, but is only rarely done and at a cost. To have a chance of making a defect free perfect barrel finish, you have to have contamination free steel.

The machinist and cutting tools need to do their part, but starting with the right steel is sometimes a matter of luck.

 

[Ray123]

Is there too smooth? Seems like that was hashed a few years ago?

Burrs and high spots I would think would be a top reason for bore treatment?

Pits, myself I never had a huge issue with. Shot a lot of cast bullets in some pitted bores. One place I think carbon had a benefit as a pot hole filler. Though I will say I have had some pits that were a total pita. Buddy fire lapped a great barrel because it fouled in about 40-50 rounds, but it cleaned easy, now it has zero fouling to speak of and shoots just OK.

Yeah, people with lots of barrel experience like Lilja and Precision Shooting test in 2000 say that the barrel can be lapped too smooth.... and one bullet jacket material, can foul more than another brand of bullet jacket material..And barrels of same interior lap and finish appearance the stainless steel barrel will have less barrel fouling than chrome moly steel... according their experiment. Does it still hold true today? I don't know. A manufacturer used to have a ceramic barrel coating applied to the barrel interior for filling in barrel pits And imperfections ... some in the Varmint Hunters club and a few gun writers praise the product, but I don't believe anyone in Precision Shooting mag endorsed it, but it still may be available to try on pitted bores. Not a fan of fire lapping, its fast, and appears really too aggressive, and easily overdone, if not careful...but Tubb sells and uses it...so what do I know!

 

[Ray123]

This is what I call "luck of the draw".

If you were to look at the steel Jackie is cutting on that shaft support, versus barrel steel, versus air melt bearing steel, and compare it to a VIMVAR grade steel, there is a huge difference in the cost and quality of the cleanliness and grain structure controls.

Some steels have lots of stringers and inclusions and other steels are processed to be nearly perfect, but that adds huge costs.

When cutting or polishing these steels, hitting those carbide clumps or inclusions is just luck of the draw. Making steel that is very clean and nearly perfect can be done, but is only rarely done and at a cost. To have a chance of making a defect free perfect barrel finish, you have to have contamination free steel.

The machinist and cutting tools need to do their part, but starting with the right steel is sometimes a matter of luck.

Yes, we use alot of recycled "steel" plus all its contamination, and for genral purposes its good enough...but for perfection & precision not so much. we have better scientific & computerized tools to aid in identifying the content elements of the metal, in question. But it all costs more to perfect, remove contaminants, & re test and analyze in many categories. But with all that sometimes inclusions, and contamination still occurs. Seen it but very rarely, once in reactor grade Zirconium, and several times in reactor grade Stainless...the material is Quarantined and locked up, any parts made are from it are scrapped, and locked in quarantine for disposal. Same in computer industry copper anodes, heavily inspected, spectrographed, with multiple samples sawed from each huge rectangle that is serialized sawed into thinner searilized rectangles for machining. Employees handling the material are "bar coded in" on handling or machining every piece. Everything serialized, documented and signed for and computer logged ...everthing!..still once in awhile the 99.9% certified copper used in your computer chip has a flaw, and must be scrapped and locked in quarantine. And you change out all your CNC tooling & wipe down your machine when changing, from copper, steel, plastic, etc...and coolent change in some materials, halfnium to zirconium, is a change out bitch... because of cross contamination, signatures and documentation required...a 10 hr day cleaning.
Standard Rifle barrel material just sitting out on racks...no one is near as concerned or particular as to the quality of barrel steel in your rifle barrel.
So yeah, some luck is, indeed, involved.

 

[INTJ]

I lap all new barrels in my shop. Just because.

Back to back ball bearings in the handle piece.

Rod guide screws onto barrel. Left hand piece is a adjustable stop so the lap will not exit the muzzle.

Breech end

Lap

Ready to lap. Note the grease fitting on the handle piece, to lubricate the bearings.

I have several lapping rods, they are interchangeable. Diameters to fit the bore size.

I remember you talking about that soft lap 20 years ago.....

 

[jelenko]

Yes, we use alot of recycled "steel" plus all its contamination, and for genral purposes its good enough...but for perfection & precision not so much. we have better scientific & computerized tools to aid in identifying the content elements of the metal, in question. But it all costs more to perfect, remove contaminants, & re test and analyze in many categories. But with all that sometimes inclusions, and contamination still occurs. Seen it but very rarely, once in reactor grade Zirconium, and several times in reactor grade Stainless...the material is Quarantined and locked up, any parts made are from it are scrapped, and locked in quarantine for disposal. Same in computer industry copper anodes, heavily inspected, spectrographed, with multiple samples sawed from each huge rectangle that is serialized sawed into thinner searilized rectangles for machining. Employees handling the material are "bar coded in" on handling or machining every piece. Everything serialized, documented and signed for and computer logged ...everthing!..still once in awhile the 99.9% certified copper used in your computer chip has a flaw, and must be scrapped and locked in quarantine. And you change out all your CNC tooling & wipe down your machine when changing, from copper, steel, plastic, etc...and coolent change in some materials, halfnium to zirconium, is a change out bitch... because of cross contamination, signatures and documentation required...a 10 hr day cleaning.
Standard Rifle barrel material just sitting out on racks...no one is near as concerned or particular as to the quality of barrel steel in your rifle barrel.
So yeah, some luck is, indeed, involved.

Do you work in semiconductor manufacturing?

 

[Will Henry]

If the barrelmaker does a good job of reaming, there will be no tool marks to iron out. One maker of cut barrels I know will not lap a barrel because, as he says, "Harry Pope didn't have to lap his; I don't have to lap mine. Lapping is to fix poor reaming". Nonetheless, I have buttoned barrels which were honed prior to rifling and lapped afterwards. I have other buttoned barrels which were only lapped after rifling and others which were not lapped at all. There are no rules. WH

 

[Ray123]

If the barrelmaker does a good job of reaming, there will be no tool marks to iron out. One maker of cut barrels I know will not lap a barrel because, as he says, "Harry Pope didn't have to lap his; I don't have to lap mine. Lapping is to fix poor reaming". Nonetheless, I have buttoned barrels which were honed prior to rifling and lapped afterwards. I have other buttoned barrels which were only lapped after rifling and others which were not lapped at all. There are no rules. WH

There are always tool marks, and reamed holes are not even round. Enlarge the hole 100 or 1000 times with photo optics, visually see the irregularities. Even CNC interpolated holes... I've checked brand new CNC machines with a CMM... how straight, how round, how square, how flat, how much spindle TIR ...they have tolerances to live by, and are somewhat linear adjustable, because they are not perfect and you have to know if your expensive new CNC is up to your customers demands. And they are Far more accurate than anything in Pope's day...although I enjoyed reading the stories.

 

[Machinist John]

What’s that lap made of? Looks like leather or something?

Heavy cowhide discs with aluminum discs between. Aluminum is smaller than the rifling so it does not contact. I rub lapping compound into the leather. The leather holds compound better than the traditional lead lap. The socket head screw on the end may be tightened to expand the leather after several strokes through the barrel.

 

[Machinist John]

I remember you talking about that soft lap 20 years ago.....

Yep the lap shown was user in one of your barrels. Old photos.

 

[L.Sherm]

Lapping is to fix poor reaming

Not necessarily, serves more than one purpose. Does take out any very minor marks from the bore reamer and to leave the finish on the barrel you desire.
Any drill or bore reamer marks are circular, hand lapped barrels leaves the finish perpendicular to the bore which you want in the same direction as the bullet traveling down the barrel.

 

[butchlambert]

Will Henry, I guess your many many years of experience means little.

 

[L.Sherm]

No, but the lap does. Can you tell me what makes the tool marks? The reamer in the bore after drilling or the button?

Butch do you just love to STIR SHIT!!

 

[butchlambert]

Butch do you just love to STIR SHIT!!

Just looking for an answer.