How inaccurate a double rifle when?

[HWL]

Have a muzzle adjustment device and all the problems are gone forever....

HWL

 

[Pondoro]

My .470 Krieghoff shoots more or less the same at 50 meters with Norma, Federal and Hornady factory.. 90 grains of N150 and 500 grain Woodie also..

 

[R eight]

My BB 97 Classic shoots / regulates differently when the scope is attached.

Not a big deal really. I’ve got a load just for the iron sights and it shoots factory PPU well enough out to 50 meters for close up hunting.

Details are written in the rifles log book. Photos of which appear below.

 

[Velo Dog]

I had to look it up but here it is for clueless people like me.

 

[R eight]

I had to look it up but here it is for clueless people like me.

View attachment 589145

The BB97 Classic has soldered barrels…none adjustable.

The standard BB 97 has the adjustable top barrel.

That’s about the only real difference.

 

[HankBuck]

My BB 97 Classic shoots / regulates differently when the scope is attached.

Not a big deal really. I’ve got a load just for the iron sights and it shoots factory PPU well enough out to 50 meters for close up hunting.

Details are written in the rifles log book. Photos of which appear below.

R Eight: If the rifle shoots significantly different POI with scope vs. without - I think that is a Big Deal…at least for Me. It would eliminate the ability to use a “Quick Detach” scope mount because it would NOT return to Zero. If POI changes by more then 2”-3” MOA I would be concerned and either Never switch the scope during a Hunt…or Buy another rifle where I could.

 

[R eight]

R Eight: If the rifle shoots significantly different POI with scope vs. without - I think that is a Big Deal…at least for Me. It would eliminate the ability to use a “Quick Detach” scope mount because it would NOT return to Zero. If POI changes by more then 2”-3” MOA I would be concerned and either Never switch the scope during a Hunt…or Buy another rifle where I could.

yes and no....of course I'd prefer it if the rifle regulated the same way whether or not the scope was on or off. But it doesn't...and I didn't buy the rifle for DG hunts. The rifle. I believe, was made for driven game hunting. I should emphasis that having the scope on or off does NOT effect the zero. But it does alter the regulation. At 50 meters whether the scope is on or not the rifle shoots well enough to place both rounds into the chest of a pig. Probably capable of putting 2 shots into a 6" circle.

With the scope on I was able to hit, more often than not, a 9" diameter steel plate at 200 yards, off hand. I really only bought the rifle, because I've always wanted a double rifle. And when I saw this beauty it was love at first sight. She's a thin lively girl to shoot, and like a few old girlfriends, not perfect .....but certainly fun and entertaining.

be interesting to see what other double owners think.

 

[Tokoloshe Safaris]

The difference between a clean and someone getting seriously hurt.

Some may agree or disagree, but from my own experience upto 4” at hunting distances. That said double rifles being what they are you may have better accuracy. Do not hunt with any ammunition that you have not tried.

Lon

In my Sabatti it’s all over the place. Federal Swift A frames almost identical but everything else I’ve tried I get varied results of anywhere from 2 to 10 inches difference at 50 yards

In my Sabatti it’s all over the place. Federal Swift A frames almost identical but everything else I’ve tried I get varied results of anywhere from 2 to 10inches difference at 50 yards

Sir I reccomend that you contact a superb gunsmith by the name of Ken Owens. He will develop a load for your Sabatti that will be spot on, with reduced recoil.

Lon

 

[deewayne2003]

The difference between a clean and someone getting seriously hurt.

Some may agree or disagree, but from my own experience upto 4” at hunting distances. That said double rifles being what they are you may have better accuracy. Do not hunt with any ammunition that you have not tried.

Lon


Sir I reccomend that you contact a superb gunsmith by the name of Ken Owens. He will develop a load for your Sabatti that will be spot on, with reduced recoil.

Lon

Well said Lon

Ken did load development & regulation on my Sabatti, also this rifle shoots the same with both Hornady & Woodleigh bullets.

 

[Tanks]

What I'm trying to get at is that a great, big strong man that leans into a gun will change the point of impact (even for a single barrelled gun) over a smaller person that purposefully lets the barrels jump to reduce their felt recoil. ...

That is absolutely wrong.

 

[Velo Dog]

The BB97 Classic has soldered barrels…none adjustable.

The standard BB 97 has the adjustable top barrel.

That’s about the only real difference.

Thanks R eight,

Before googling it, I had no idea what your reference to a “BB 97” was.
At first I thought you might have been in jest, referring to some sort of air rifle.
Thanks for the info on this one.
I learned something new here.

Cheers,
Velo Dog.

 

[Rare Breed]

Given I am now on my seventh DR and hand load for them all, I have found the following:
1. Regardless of powder and bullet type, match the bullet weight and FPS that the rifle was regulated with…you will be 95% there with good regulation.
2. DRs are finicky beauties…there are always exceptions but if you start at the above find out what your shots are doing…crossing at 50 yards?…slow down your FPS, too wide apart yet not crossing increase your FPS.
In all my rifles with my most recent 470 that I now have shooting under an inch at 50 yards with same bullet weight but different type bullet and powder used for regulati

Well said Lon

Ken did load development & regulation on my Sabatti, also this rifle shoots the same with both Hornady & Woodleigh bullets.
View attachment 589233

He did my Sabatti as well and it was within 2 inches. 500 NE 570 grain bullet 80 grains IMR3031

 

[Rubberhead]

That is absolutely w

I can't argue with you. But, listen to the guy from Heym at about 2:30...

 

[HankBuck]

yes and no....of course I'd prefer it if the rifle regulated the same way whether or not the scope was on or off. But it doesn't...and I didn't buy the rifle for DG hunts. The rifle. I believe, was made for driven game hunting. I should emphasis that having the scope on or off does NOT effect the zero. But it does alter the regulation. At 50 meters whether the scope is on or not the rifle shoots well enough to place both rounds into the chest of a pig. Probably capable of putting 2 shots into a 6" circle.

With the scope on I was able to hit, more often than not, a 9" diameter steel plate at 200 yards, off hand. I really only bought the rifle, because I've always wanted a double rifle. And when I saw this beauty it was love at first sight. She's a thin lively girl to shoot, and like a few old girlfriends, not perfect .....but certainly fun and entertaining.

be interesting to see what other double owners think.

R eight: I have No idea what you are saying so any comments I make are not going to be helpful or insightful. Per your post ie: “scope on/off does Not effect Zero? But DOES affect regulation?” I view the two as related. Also you can only shoot a 6” group at 50 meters but a 9” group at 200 yards “off hand”?? Shooting 9” Off Hand at 200 yards is some fine shooting.

 

[HankBuck]

Have a muzzle adjustment device and all the problems are gone forever....

HWL

HWL: True but then the barrel of your gun looks like sh-t forever too….like putting a Halloween Mask on a Beauty Queen. (But function is more important then form so I guess You are Right)

 

[Mark A Ouellette]

What I'm trying to get at is that a great, big strong man that leans into a gun will change the point of impact (even for a single barrelled gun) over a smaller person that purposefully lets the barrels jump to reduce their felt recoil. Like someone said, there are a lot of variables.

In theory this is correct. In application one may not notice much difference.

1. The weapon, rifle or handgun (or shotgun..) starts moving opposite of the outgoing projectile as soon as the bullet starts to move due to expanding gasses of the burning powder.

2. The rearward moving weapon will move a certain distance at an accelerating rate if the weapon is unopposed, i.e. somehow suspended in air.

3. The rearward moving weapon would also experience angular movement if the line of the bore is not perfectly centered against any "opposition to recoil". This caused the muzzle rise or jump.
3.1. Deeper in theory, an unopposed weapon would experience some muzzle rise based on the distribution of mass within the weapon. How much? Darned if I could even guess...

4. Since the most weapons, be they hunting rifles or handguns, have their axis of their bores situated above the of where their rifle butt or handgun grip moves rearward (recoils) against an opposition to recoil (shooter's shoulder or hand), they will experience muzzle rise BEFORE the projectile exits the muzzle.

5. To maintain consistent point of impact (POI), shooters must present a consistent opposition to recoil. This allows the muzzle of the recoiling weapon to be at the same point when the bullet exits each and every shot. (axis of the bore when the projectile exits in relation to the axis of the bore when the recoil was initiated).

6. The above is most noticeable when shooting handguns at targets. Providing the shooter can maintain a certain size POI on the target, tightening or loosening the grip of the shooting hand and wrist will change the POI very noticeably.

7. The same effect is more noticeable the higher the recoil energy and/or recoil velocity providing the same opposition to recoil.

8. If one is shooting large steel plates at short range, a change in POI may not affect the outcome of targets hit. If however one is shooting at small 10-rings at longer range, a shift in POI may produce a hit in the lower scoring rings, i.e. flyer.

9. The more stable shooting positions (bench rest, prone and so on) will provide more consistent opposition to recoil than less stable positions (offhand/standing).

10. For a DGR, changing the opposition to recoil should produce a different POI.
10.1. A small man may however produce more opposition to recoil than does a larger man.
10.2. Opposition to recoil is hard to quantify.
10.3 Opposition to recoil is however easier to observe in videos or photos of shooters firing the same weapon with the same loads.
10.4. Shooting powerful DGR at short ranges may not produce very noticeable shifts in POI. Shoot the same at 200 yards and try changing your opposition to recoil and see what happens!

11. The above in theory may also affect regulation of a double rifle due to the barrels may have different amounts of LATERAL movement (right and left) with different levels of opposition to recoil.
11.1. The upward movement of a double rifle in recoil will only affect the POI.
11.2. But in a SxS double rifle, the barrels also recoil outwardly from the axis of the each bore, but much less so than they rise in recoil.
11.3 How much different opposition to recoil will affect regulation may not be much at all, i.e. not measurable especially at short range.

12. Every shooter and every rifle is unique in there own way! Practical application trumps theory! Practice, practice, practice...

For ALL OF THE ABOVE THEORY, each shooter is different, as are each rifle.

Your results may vary...

 

[HankBuck]

In theory this is correct. In application one may not notice much difference.

1. The weapon, rifle or handgun (or shotgun..) starts moving opposite of the outgoing projectile as soon as the bullet starts to move due to expanding gasses of the burning powder.

2. The rearward moving weapon will move a certain distance at an accelerating rate if the weapon is unopposed, i.e. somehow suspended in air.

3. The rearward moving weapon would also experience angular movement if the line of the bore is not perfectly centered against any "opposition to recoil". This caused the muzzle rise or jump.
3.1. Deeper in theory, an unopposed weapon would experience some muzzle rise based on the distribution of mass within the weapon. How much? Darned if I could even guess...

4. Since the most weapons, be they hunting rifles or handguns, have their axis of their bores situated above the of where their rifle butt or handgun grip moves rearward (recoils) against an opposition to recoil (shooter's shoulder or hand), they will experience muzzle rise BEFORE the projectile exits the muzzle.

5. To maintain consistent point of impact (POI), shooters must present a consistent opposition to recoil. This allows the muzzle of the recoiling weapon to be at the same point when the bullet exits each and every shot. (axis of the bore when the projectile exits in relation to the axis of the bore when the recoil was initiated).

6. The above is most noticeable when shooting handguns at targets. Providing the shooter can maintain a certain size POI on the target, tightening or loosening the grip of the shooting hand and wrist will change the POI very noticeably.

7. The same effect is more noticeable the higher the recoil energy and/or recoil velocity providing the same opposition to recoil.

8. If one is shooting large steel plates at short range, a change in POI may not affect the outcome of targets hit. If however one is shooting at small 10-rings at longer range, a shift in POI may produce a hit in the lower scoring rings, i.e. flyer.

9. The more stable shooting positions (bench rest, prone and so on) will provide more consistent opposition to recoil than less stable positions (offhand/standing).

10. For a DGR, changing the opposition to recoil should produce a different POI.
10.1. A small man may however produce more opposition to recoil than does a larger man.
10.2. Opposition to recoil is hard to quantify.
10.3 Opposition to recoil is however easier to observe in videos or photos of shooters firing the same weapon with the same loads.
10.4. Shooting powerful DGR at short ranges may not produce very noticeable shifts in POI. Shoot the same at 200 yards and try changing your opposition to recoil and see what happens!

11. The above in theory may also affect regulation of a double rifle due to the barrels may have different amounts of LATERAL movement (right and left) with different levels of opposition to recoil.
11.1. The upward movement of a double rifle in recoil will only affect the POI.
11.2. But in a SxS double rifle, the barrels also recoil outwardly from the axis of the each bore, but much less so than they rise in recoil.
11.3 How much different opposition to recoil will affect regulation may not be much at all, i.e. not measurable especially at short range.

12. Every shooter and every rifle is unique in there own way! Practical application trumps theory! Practice, practice, practice...

For ALL OF THE ABOVE THEORY, each shooter is different, as are each rifle.

Your results may vary...

MARK: This is an “Einstein” like theory that could only be “imagined” and has Never been demonstrated in any experiment….and Never could be. There has been demonstrations of “barrel whip: where a rifle barrel is laid in contact with a hard surface and then “fired”, the POI has been shown to change (usually Higher) due to the barrel vibrations being altered when resting on a hard surface - since barrel vibrations occur during every shot fired “any change” can alter POI - even placing a barrel band sling attachment on the barrel. But, I am Unaware of any test or demonstration being conduction on Your Einstein Theory of BIG STRONG SHOOTER Relativity and therefore think it is a “theory only” and highly unlikely to even change POI 1/1000 of an inch at 1000 yards. (That’s my BS theory and I can’t prove that either).

 

[Tokoloshe Safaris]

Keep it simply my friend send it to Ken!

 

[Hillcountry63]

Lon my rifle is 1” at 50 yards with the ammo it was regulated with and just over that with Federal Swift A Frames. My point was and is, with various ammo you get different results that can be all over the place….which was the point of the question. I am very familiar with Ken and his excellent work.

The difference between a clean and someone getting seriously hurt.

Some may agree or disagree, but from my own experience upto 4” at hunting distances. That said double rifles being what they are you may have better accuracy. Do not hunt with any ammunition that you have not tried.

Lon


Sir I reccomend that you contact a superb gunsmith by the name of Ken Owens. He will develop a load for your Sabatti that will be spot on, with reduced recoil.

Lon

 

[Mark A Ouellette]

Your Einstein Theory of BIG STRONG SHOOTER Relativity and therefore think it is a “theory only” and highly unlikely to even change POI 1/1000 of an inch at 1000 yards. (That’s my BS theory and I can’t prove that either).

Well my friend, I can demonstrate most of this in my back field on a 100 yard range. I did so yesterday to myself shooting .38 Super in my lightweight Accuracy X Commander size 1911. Shooting 125 gr loads at 1300 fps, if I "limp wristed" any shot the POI was at least 2" higher at 25 yards and more than double that at 50 yds.

Back in the day when I shot 1000 yard matches such as the Wimbledon Cup while on the Marine Corps Rifle Team, small changes in position such as the firmness of the shooting hand grip would the POI by a scoring ring or more. The same was true at the 600 yd line with match iron sighted M-14's. That's at least 1/2 MOA. Of course those were shot prone with a sling to stabilize the rifle rather than a bipod. Shooting 10-X or 20-X, depending on the match, isn't easy in Service Rifle or prone 1000 yd matches.

As you point out there are other factors that may affect POI such as barrel vibrations. But if all mechanical aspects (to include what a barrel WILL do each shot) are the same shot to shot, and our ammunition is loaded as perfectly as can be done, then it's application. Application involves a lot of human variables. Will any of this affect the POI of a rifle? Practice and find out! Consistency is the key to shooting small groups.

If a 2" group at 50 yds is good enough, and for a 500 Nitro I think so, then all of this is theory and nothing to worry about. The same is true of atomic theory, how an EMP functions and affects electronics, the human body, and so on. There are however some people that like to know what makes things tick!

Einstein? Hardly, more of a Captain Gadget and often a Captain Obvious...

Shoot well and be safe!

Of course, my shooting background from years past includes a lot of competition.