Fact or fiction?

[CANNONMAN]

While learning techniques on how to accurize a rifle, bedding, triggers and such, a discussion ensued concerning what happens when a barrel is touched post the action. Sort of like why to forend is floated during bedding to prevent this. The discussion was that pressure on the barrel will change the POI. Then this: A shooter who knows his rifle can adjust the POI by knowing where to apply pressure to the barrel. This is done by the non-trigger hand resting on top of the barrel and knowing where and how much pressure to apply to correct the POI. Fact or Fiction?

 

[jmr40]

In theory possible, in practice I doubt it. It is generally accepted that free floating is the easiest way to get consistent accuracy. But having pressure on the barrel can achieve the same goals. But it requires a lot of experimentation and anything that changes the amount of pressure will result in varying POI.

The key is that whatever you do has to be the same for every shot. Free floating is the most consistent. It is a lot easier to keep everything the same from shot to shot. Many rifles will actually shoot more accurately with a barrel that is fully bedded, or with some pressure at the tip of the stock. But if anything changes, such as atmospheric conditions, the POI will change.

I've never heard of anyone attempting to do this with their hands. Seems like it would be almost impossible to be consistent from shot to shot.

 

[dave951]

Theoretically possible? YES. By hand? NO. The barrel vibrates as the round is fired. When the vibration crosses the X axis at the muzzle is the point where most barrels will deliver the best accuracy (node point). Weight or pressure on the barrel changes the harmonics. No way you're going to consistently do it by hand.

 

[Varminterror]

Fiction.

 

[Demi-human]

Man, I just bought a three hundred dollar bipod. I am so dumb, I could have just used my hand...

The finely tuned measuring, and torque applying, device that it is...

Then this: A shooter who knows his rifle can adjust the POI by knowing where to apply pressure to the barrel.

Ha! Silly me! This whole time I’ve been adjusting my aiming!

 

[Swampman]

While learning techniques on how to accurize a rifle, bedding, triggers and such, a discussion ensued concerning what happens when a barrel is touched post the action. Sort of like why to forend is floated during bedding to prevent this. The discussion was that pressure on the barrel will change the POI. Then this: A shooter who knows his rifle can adjust the POI by knowing where to apply pressure to the barrel. This is done by the non-trigger hand resting on top of the barrel and knowing where and how much pressure to apply to correct the POI. Fact or Fiction?

Fiction.
I'm pretty sure that's why adjustable sights and "Kentucky windage" were invented...

 

[Demi-human]

Theoretically possible? YES. By hand? NO. The barrel vibrates as the round is fired. When the vibration crosses the X axis at the muzzle is the point where most barrels will deliver the best accuracy (node point). Weight or pressure on the barrel changes the harmonics. No way you're going to consistently do it by hand.

Right. It is not fiction. It happens and is the reason for free floating a barrel and keeping it from touching anything while firing, with long forearms resting on the barricade/rest, not the barrel.


This...

"I’ll put a little ‘English’ on this one with my thumb, and Masse around that sapling and heart shoot him..”
"The wind is heading East at three, I’ll put three fingers on the left side of my barrel to adjust...”

...is fiction.

Funny, we were talking something similar in the shop this week.
The understanding of the physics of our world is not universal.

 

[edwardware]

If the forend contacts the barrel, then hand-on-forend force will shift POI, repeatably so. It's the nut holding the stock that adds all the variation and noise to that equation.

For me, on bags and bench, seated, in a single session, being as consistent as I can, hand-on-forend force is worth 1+MOA extra dispersion vs free-floated barrel. In other words, it's a waste of ammo, and all my rifle barrels are floated.

 

[BrocLuno]

There may be other ways to get near accuracy desired ... Shifting POI is to spooky for me. You'd have to have a pressure point table taped to the stock for each bullet weight and powder charge. Then be able to apply just that pressure. Maybe with a sliding strain gauge ...

But I like to tinker. Some barrels seem to be susceptible to dampening. There was an old thread here about a guy who got better than expected accuracy out of a Moisen Nagant with a sleeved barrel filled with high temp epoxy matrix.

Sometime next year, I'll be trying that with an Arisaka (skinny barrel) with a sleeve filled with mold makers high temp polymer (urethane). Since it's a bolt gun, it does not get shot fast enough to heat up much. We'll see how it responds

 

[d2wing]

Fiction. Extremely hard to be consistent and other factors enter in. How can you know what effect touching your barrel will have? What pressure and location does what? Maybe a small adjustment in Aim point with a non critical situation like close range big target. In fine shooting no.