Does barrel straightness effect accuracy.

A

ab_bentley

Guest
I asked this question and found that many believe it does. I don't, I believe a straight chamber, concentric and inline to the bore is the key. If there's a curve, time it to 6 or 12. I understand frozen scope issues with curved barrels, but that's not the point. I figured I'd come come to the gurus and ask. Adam
 
No barrel's ID is truly straight. But, they are also not "curved" in the sense of a banana shape.

Most have spots that will run out in one direction, only to have spots run out in an opposite direction at another location.

I like to see Barrels that exhibit very little optical runnout when looking at the ID as it turns in the Lathe. But I can't say definitively whether it affects the accuracy potential of the barrel.
 
Some of the best of the hummers havee barrels with a curve. If the chamber is cut accurately and the muzzle is pointed straight ahead the barrel should shoot accurately shooting a tuned load.

If you have a barrel zeroed and you change barrels the POI should be not over +/- about 3” of where the previous barrel hit.
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i have tested and i have seen absolutely no correlation in accuracy between really curved barrels and straighter barrels. None are perfect. I have seen a few that were close, but never a perfectly straight one. Also putting the muzzle directly in front of the chamber or leaving it to run were it may also has no correlation to accuracy. 100 to 300 yards shooting anyway. Lee
 
JerrySharrett said:
Some of the best of the hummers havee barrels with a curve. If the chamber is cut accurately and the muzzle is pointed straight ahead the barrel should shoot accurately shooting a tuned load.

If you have a barrel zeroed and you change barrels the POI should be not over +/- about 3” of where the previous barrel hit.
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When I swap barrels on my Panda action the .22-250 AI is 1 inch right and 2 inches high compared to the 6 mm Rem AI barrel.

It is repeatable enough to move adjust the scope and easily hit withing a small fraction of an inch out to at least 400 yards with additional drop adjustment for range.

I actually rarely really 'scrub' at the barrels when cleaning.
I prefer them to have first shot accuracy for groundhog hunting, so at least 'minute of chuck.'
 
My opinion is maybe, but its not because of the straightness, but maybe because of why it drilled straight. The muzzle is always in front of the chamber even if we index the barrel. Remember the barrel always points at the target, we index the rifle behind it.
 
A few years back, I took a discarded unlimited barrel and cut it into equal 3 inch long pieces so Shooters could see how the bore actually wonders inside a blank.

I first scribbed a straight line down the full length of the blank. This gave a master references. After parting the barrel onto the three inch long pieces and facing them square, you could measured the groove diameter in relation to the ID to assertain the run out and it's relation to the OD.

Some of the spots were a full 180 degrees opposite of the others. If I remember correctly, some were as much as .003 in just a 3 inch distance.

It really doesn't do much good to do experiments like this and actually show people what is going on with a barrel's ID. Gunsmiths still try to convince themselves that the ID is "bowed", when in reality it is just crooked in different directions with its self.
 
jackie schmidt said:
A few years back, I took a discarded unlimited barrel and cut it into equal 3 inch long pieces so Shooters could see how the bore actually wonders inside a blank.

I first scribbed a straight line down the full length of the blank. This gave a master references. After parting the barrel onto the three inch long pieces and facing them square, you could measured the groove diameter in relation to the ID to assertain the run out and it's relation to the OD.

Some of the spots were a full 180 degrees opposite of the others. If I remember correctly, some were as much as .003 in just a 3 inch distance.

It really doesn't do much good to do experiments like this and actually show people what is going on with a barrel's ID. Gunsmiths still try to convince themselves that the ID is "bowed", when in reality it is just crooked in different directions with its self.
Click to expand...

And if you do a decent simulation of the vibrations a barrel goes though as the bullet travels the length the muzzle is often moving around a lot more than you might think unless you have managed to produce a vibration node at the muzzle by adding some mass that is no longer affecting the bullet. A 'tuner.'

I could see the effect very nicely on my old F150 with an actual antenna on the RF fender..
The ball on the tip produced a vibration node in rain that was about 1 inch lower on the antenna.

My favorite ME and I would use it to 'remind' new grads on the drive to lunch.
 
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jackie schmidt said:
A few years back, I took a discarded unlimited barrel and cut it into equal 3 inch long pieces so Shooters could see how the bore actually wonders inside a blank.

I first scribbed a straight line down the full length of the blank. This gave a master references. After parting the barrel onto the three inch long pieces and facing them square, you could measured the groove diameter in relation to the ID to assertain the run out and it's relation to the OD.

Some of the spots were a full 180 degrees opposite of the others. If I remember correctly, some were as much as .003 in just a 3 inch distance.

It really doesn't do much good to do experiments like this and actually show people what is going on with a barrel's ID. Gunsmiths still try to convince themselves that the ID is "bowed", when in reality it is just crooked in different directions with its self.
Click to expand...

I think you would find a lot of gunsmiths understand the barrel is not a simple curve. I "time barrels", because I have to put the runout somewhere. Its a consequence of making sure the chamber is coaxial to the first inch of bore directly in front of it. But like I said, I am really indexing the rifle, barrels dont point up in the air, they point at the target no matter how you do your chambering. I think thats where a lot of guys picture things wrong. Kind of like when you read about guys bedding the barrel high to drive the stock down into the bags. The barrel still ends up pointing at the target and is not driving anything "down"
 
zfastmalibu said:
I think you would find a lot of gunsmiths understand the barrel is not a simple curve. I "time barrels", because I have to put the runout somewhere. Its a consequence of making sure the chamber is coaxial to the first inch of bore directly in front of it. But like I said, I am really indexing the rifle, barrels dont point up in the air, they point at the target no matter how you do your chambering. I think thats where a lot of guys picture things wrong. Kind of like when you read about guys bedding the barrel high to drive the stock down into the bags. The barrel still ends up pointing at the target and is not driving anything "down"
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So, no....?
 
If a barrel goes into a rifle in a forest and the owner doesn't know if it's straight or not, will it still shoot OK?
 
zfastmalibu said:
Im still a solid maybe. But not because the bore is drilled straight, rather why it drilled straight.
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This is as likely as anything to be correct.
It drills straight because the steel is VERY uniform.

Barrel drilling is a real PITA to do well.
It is the ultimate test of 'deep hole' drilling technique.

The drill bits have a very special face on them that does not look like ANY other drill you have seen.
Often they are mostly flat with a single cutting face in the front and hollow.

There is a groove in the side and a hollow for the length.
Oil goes down the side and returns with chips in the hollow.

The cutting face is designed to make very small chips.

When it pours out the muzzle you broke through.
 
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Aligning your bullet up to enter the rifling straight is important, after that the next important stage is the moment of exit, none of us can determine the rest of the journey.

After that is all in the component choice and load development assuming the barrel, action, stock, trigger, bedding and shooter are all good.

If only straight barrels made hummers there wouldn't be many.
 
There aren't many

Curious said:
Aligning your bullet up to enter the rifling straight is important, after that the next important stage is the moment of exit, none of us can determine the rest of the journey.

After that is all in the component choice and load development assuming the barrel, action, stock, trigger, bedding and shooter are all good.

If only straight barrels made hummers there wouldn't be many.
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hummers.

I had a dialogue with a person who has a laboratory and is able to determine why a hummer is a hummer. He said the most accurate barrels are those that are dead straight. He has one that Shilen made for him. He would readily say it's a rare one.

I tend to believe a lad who has a laboratory with a staff or people who know what they are doing when they test thing, doing it for a living, etc.

One would think, after all these years of drilling holes through rods, a more accurate way to do it would have been developed. When one watches some of the multi axis machines make parts of all descriptions and hold exceeding tight tolerances, it just must be possible to make straight holes.

It would seem to me that everyone, including the barrel makers would benefit. My thinking is, there ain't no future in the past.

Pete
 
I hate straight barrels.

So much easier to tune a barrel with a curve.

I don't believe anyone in any lab knows deck about rifle accuracy.

IMO the single rule that started real accuracy still applies, "fiddle with the gun until it makes vertical, then tune out the vertical"

A crooked barrel makes it easier to find vertical.

I am dead serious.
 
I always knew

alinwa said:
I hate straight barrels.

So much easier to tune a barrel with a curve.

I don't believe anyone in any lab knows deck about rifle accuracy.

IMO the single rule that started real accuracy still applies, "fiddle with the gun until it makes vertical, then tune out the vertical"

A crooked barrel makes it easier to find vertical.

I am dead serious.
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You were a "Leftie" Al. one of them 10 percenters.

I think and am pretty sure some people still think the world is flat but I accept that. How about a world where one never had to tune a barrel?

Pete
 
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alinwa said:
I hate straight barrels.

So much easier to tune a barrel with a curve.

I don't believe anyone in any lab knows deck about rifle accuracy.

IMO the single rule that started real accuracy still applies, "fiddle with the gun until it makes vertical, then tune out the vertical"

A crooked barrel makes it easier to find vertical.

I am dead serious.
Click to expand...

If not dead vertical.
 
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