SUNNEN HONEING GUN BARRELS

[savagedasher]

What manufacture is doing it ? Larry

 

[STS]

Bartlein I believe. I have a friend that did some of the engineering on the hone and put the first one in service for them. If I remember correctly he told me that they had a second hone either in the works or in place.

 

[cmillard]

feddersen does

 

[savagedasher]

tt

 

[Gappmast]

check out the pictures on the Pac Nor web site it looks like they have one.

 

[savagedasher]

Thanks any others. Larry

 

[redrockranger]

X-Caliber.It's pictured on their website.

 

[Rustystud]

This machine can not feel and does not exude elbo grease.
Nat Lambeth

 

[savagedasher]

Feb 24 bulletin. Can be a good read. Sunnen makes hone's for the aircraft and automotive industry.
Larry

 

[savagedasher]

feddersen does

Feddersen says.
The Sunnen HTC-series tube honing system can impart accuracy-enhancing bore geometry and size
(+ - 0.00005 inches end-to end with a finish of 3 to 8 micro inches RA. Larry

 

[Gappmast]

I understand that Benchmark Barrels has also bought one.

 

[savagedasher]

I understand that Benchmark Barrels has also bought one.

I just got a new Bartlein . My smith said it was the straights barrel he had ever chambered.
Not only was it straight I never had one that broke in and shot that good with just 12 shots. After shooting two and cleaning . I did two 5 shots then cleaned. After two patches with solvent.I used a larger patch the pressure was the same from chamber to the crown.
Honing is the biggest change in barrel making in years. Larry

 

[David Sengelaub]

The honing tools used in the HTE1600 honing machine have 1.500" long abrasives. The abrasives bridge across the top of the waviness left by the reamer, and the hone removes the peaks leaving the bore straight and smooth.

Feddersen is correct the machine will make a very straight bore end to end.

 

[gunsandgunsmithing]

This machine can not feel and does not exude elbo grease.
Nat Lambeth

Nat, have you ever used one and know how they actually operate? They are an extremely accurate way of finishing a bore id. There, IS a feel in their use and gages to verify with, along with adjustable pressure. They work well and exude honing oil. I'm glad to hear that barrel makers have moved toward them. The bore will be more uniform as well as straighter. RF guys should love it, as a slight taper can be accurately lapped into the bore before rifling, too. Finishes can be varied and lapped afterward by traditional means, but I bet a better finish could be attained with the hone, even though it would go opposite to bullet travel. That's something the makers will have to test, as I've not used one for barrel making, but the principle is the same. I've used them for connecting rod and main journal reconditioning. I see no reason why it can't be superior to what barrel makers have been doing.

 

[stansrifles]

I disagree with the straightening part a crooked hole is a crooked hole honing is not going to make the barrel straight internally straightness comes from the drilled hole.
Stan

 

[savagedasher]

Cam bearing bore, main bearings ,lifter bore, piston bore, & both end of the connection rods. All are made straight an to 0.00005 or less in building race motors. With Sunnen Honing. Larry

 

[Alex Wheeler]

Larry, I used to have access to a Sunnen hone that we would use to hone the big and small end of our rods and the wrist pin bore in the piston. It was a great machine and had plenty of feel. In my opinion if reamed a little small and honed to size it would be far superior to a reamed finish. I think the straightest bore would be RAM EDM. But I dont know it you could burn a hole that deep.

 

[David Sengelaub]

We have to define straightness and what a hone can do to effect straightness. Straightness could be defined as the diameter of the bore from end to end, or it could refer to bend or banana shape of the hole. Rigid hones that Sunnen makes will always make the hole straight and round from end to end. In many cases it will remove the bend or banana shape.
To remove the bend or banana shape you have to have an abrasive length as long as or longer than the length of the bore. When main bearing bores on an engine block are honed the honing tool has 10 or 15 stones end to end. The abrasive length is longer than the length of the block and it removes all the banana shape.
In the case of a gun barrel the stone is shorter than the part length so the hone will not remove the banana shape. The stone is long enough to remove the waviness, galling, and size variation left by the reamer. Leaving the hole straight and round from end to end with a good consistent finish

 

[jbhotrod]

Is a curved/crooked bore necessarily a bad thing? As long as the bore dimensions are uniform, and as long as you clock/index the curve in the direction that you want it to be, who's to say a curve is detrimental to accuracy? Just wondering..

Im sure tighter control over finished dimensions is a benefit, but Im not so sure a curved barrel = bad barrel?

 

[Barlow]

We have to define straightness and what a hone can do to effect straightness. Straightness could be defined as the diameter of the bore from end to end, or it could refer to bend or banana shape of the hole. Rigid hones that Sunnen makes will always make the hole straight and round from end to end. In many cases it will remove the bend or banana shape.
To remove the bend or banana shape you have to have an abrasive length as long as or longer than the length of the bore. When main bearing bores on an engine block are honed the honing tool has 10 or 15 stones end to end. The abrasive length is longer than the length of the block and it removes all the banana shape.
Interesting. What is the physical makeup of the stones? Barlow
In the case of a gun barrel the stone is shorter than the part length so the hone will not remove the banana shape. The stone is long enough to remove the waviness, galling, and size variation left by the reamer. Leaving the hole straight and round from end to end with a good consistent finish