Orientation of lands to the perpendicular?

[BMG]

Hi Guys

I am about to fit my 2 new 4 groove barrels to the action of my rifles. I was wondering if the orientation of the 4 lands/grooves to the perpendicular makes any difference to the accuracy/harmonics of the barrel. I thought about asking the rifle smith to either orientate the finished position of the grooves at 12, 3, 6 and 9 o'clock or orientate the grooves at +45 degrees and -45 degrees to the perpendicular, or doesn't it matter what angle the grooves are positioned?

Many thanks for your input.

BMG

 

[CatShooter]

Hi Guys

I am about to fit my 2 new 4 groove barrels to the action of my rifles. I was wondering if the orientation of the 4 lands/grooves to the perpendicular makes any difference to the accuracy/harmonics of the barrel. I thought about asking the rifle smith to either orientate the finished position of the grooves at 12, 3, 6 and 9 o'clock or orientate the grooves at +45 degrees and -45 degrees to the perpendicular, or doesn't it matter what angle the grooves are positioned?

Many thanks for your input.

BMG

It makes no difference...it is OCD.

 

[watercam]

Interesting premise but in the end I believe it makes no difference either. There are so many other factors between barrels (molecular structure and variable 'mix' of alloy components of each particular one to start with) I simply get zeros for each one and go shooting.

 

[amlevin]

It makes no difference...it is OCD.

Au contraire, mon frère. It makes a BIG difference if you suffer from OCD which many here do.

 

[dkhunt14]

In rimfire where they can orient their barrels by indexing. They say one place always shoots better. Hard to do with a threaded barrel. Matt

 

[savagedasher]

Why would you worry about where the lands start or end up. Most good gun smith time the curve in the barrel up or down. Larry

 

[CatShooter]

It makes no difference...it is OCD.

Au contraire, mon frère. It makes a BIG difference if you suffer from OCD which many here do.

You made me laugh out loud!!

 

[Syncrowave]

Depends on whether you're in the Northern or Southern Hemisphere.

 

[Steve Blair]

It makes no difference...it is OCD.

[br]
You're wrong about rifling orientation being unimportant. If there is a groove at the leade bottom, the bullet feels unsupported and this leads to low self-esteem and it will never realize its potential. If there is a land at the leade bottom, the bullet feels supported and nurtured, and gives it the confidence to be all that it can be. But the worst situation is if a land-groove junction is at the bottom. This sends very mixed messages to the bullet and it has no idea where to go or how to get there. [br]
I have no evidence of this but feel like it really must be true.

 

[MrMajestic]

You're wrong about rifling orientation being unimportant. If there is a groove at the leade bottom, the bullet feels unsupported and this leads to low self-esteem and it will never realize its potential. If there is a land at the leade bottom, the bullet feels supported and nurtured, and gives it the confidence to be all that it can be. But the worst situation is if a land-groove junction is at the bottom. This sends very mixed messages to the bullet and it has no idea where to go or how to get there. [br]
I have no evidence of this but feel like it really must be true.

;D, Clinical study? I suppose a large percentage of incarcerated bullets were found to have come from "groove at the bottom" barrels.

 

[CatShooter]

It makes no difference...it is OCD.

[br]
You're wrong about rifling orientation being unimportant. If there is a groove at the leade bottom, the bullet feels unsupported and this leads to low self-esteem and it will never realize its potential. If there is a land at the leade bottom, the bullet feels supported and nurtured, and gives it the confidence to be all that it can be. But the worst situation is if a land-groove junction is at the bottom. This sends very mixed messages to the bullet and it has no idea where to go or how to get there. [br]
I have no evidence of this but feel like it really must be true.

My first laugh of the day...

 

[joshb]

Too funny! Seriously bet the guys at the Pentagon spent a couple million tax dollars on a study.

 

[amlevin]

;D, Clinical study? I suppose a large percentage of incarcerated bullets were found to have come from "groove at the bottom" barrels.

Perhaps we could "rehabilitate" them quickly by firing them from a "properly oriented barrel".


BTW, this proves that 3 and 5 groove barrels are superior. Easier to have a land oriented with the 12/6 axis

And to steal a line from Jimmy Buffet, (sort of) "it's always 6 O'Clock somewhere down that barrel"

 

[4xforfun]

OK....Question.

One of my smiths "indexes" ALL of the match tubes he chambers for me. What is he indexing? My guess is the positioning of the lands.

 

[Erik Cortina]

In rimfire where they can orient their barrels by indexing. They say one place always shoots better. Hard to do with a threaded barrel. Matt

This has more to do with barrel harmonics than with land orientation.

 

[Erik Cortina]

OK....Question.

One of my smiths "indexes" ALL of the match tubes he chambers for me. What is he indexing? My guess is the positioning of the lands.

He points the barrel up or down.

 

[Bob3700]

For those OCD impared.

Once the barrel is centred in the lathe, the smith will place a dial indicator in the muzzle end. There is a hi and a low spot as the bores are seldom if ever straight.

The smith then marks the hi and low spot on the bbl. If you are having more than one bbl chambered, tell the smith to index both barrels the same. IE, both of them with the hi spot at 12 O'clock or at 6 O'clock.

That way your sights will not have to be adjusted appreciably when bbls are changed. You will be amazed how close the two bbls will shoot.

Bob

 

[4xforfun]

OK....Question.

One of my smiths "indexes" ALL of the match tubes he chambers for me. What is he indexing? My guess is the positioning of the lands.

He points the barrel up or down.

OK..that makes sence, since I swap out BBLs a lot , and they all shoot close to each other.