Sabatti double rifles

[johneracer]

By no means I would consider myself an expert but I think elevation between barrels has more to do with shooting technique than regulation. Heavy recoiling guns are very touchy to get to shoot and replicate factory regulation so I would consider those targets more than acceptable. I very well could be wrong on this, I am a long time rifle shooter but just got into doubles. For my bolt guns to shoot 1inch moe I really have to focus on my shooting and shoot consistently. Same pressure, hold etc. when I shoot my double if I apply the same principle and try to shoot barrels identically, I get good results. Quick target aqusition from different hold will put the shots higher or lower.

 

[DUGABOY1]

The thing is when proving a double rifle to show true regulation there is a procedure for targeting the rifle and two shots from each barrel firing only one barrel at a time is not it!


First what you are looking for is not bullet holes but centers of each barrels’ individual four shot group. These shots should all be taken from cool barrels, fire right then left within five seconds. Then let the barrels cool to room temperature, then fire the next right and left, again let the barrels cool, and repeat till you have four shots from each barrel, and then find the CENTERS of each barrels’ individual group of four shots.


This should be done with the rifle not touching anything but your face, hands and shoulder. With your forearm resting on a sand bag holding the fore end tightly in your fingers.


If properly regulated the CENTERS of both barrels’ individual group will be equal to half the distance between the centers of each barrels’ bore centers on it’s own side of the aiming point along a horizontal line through the center of that aiming point at the distance the sight is filed for. These CENTERS of Barrel groups will never cross from a properly regulated double rifle. They will remain parallel to infinity, even though as the groups get larger down range some bullets will spill over into the opposite barrels group.


The reason for all this is a double rifle is designed to be fired RT, LFT from cool barrels. As the barrels heat the regulation will open up and the double is not often fired more that four shots, two from each barrel under hunting conditions. SO, to regulate the rifle properly the first four shots , two from each barrel should be on target, and the rounds five and six will begin to open the group.


Nothing you have learned from shooting a single barreled rifle will help you with the proper use of a double rifle! They are simply Zebras of two different stripes!


Most people who are new to double rifles think the rifle is regulated to cross at the range engraved on the back sight, but they are not, that distance is only to be on for elevation
........................................Mac

 

[johneracer]

I agree,,,it kills me when guys compare bolt action accuracy to a double. "My Xxx bolt action shoots 1" moe so I would never buy a double that shoots 4". These people don't understand that a double is 2 rifles, independent (sort off) of each other. Yet most of these guys can't shoot a bolt action 1 inch. Shoot 10 shots with a bolt action and get your true moe and then we'll talk. Any double, shot by anyone that shoots 3" moe or less (real world conditions) is great!

 

[sestoppelman]

moe??

 

[K-man]

moe??

Minute Of Elephant or Eland

 

[sestoppelman]

Ahh, got it. I wondered why he was talking about one of the Three Stooges. So why the 1" in front of moe?

 

[johneracer]

Haha, yes minute of elephant. Should be moa, damn spellcheck,,,

 

[edward]

way over my head,my double shoots less than 2 inches at fifty yards with two different loads.to me thats one dead animal with proper shot placement and bullet construction.thats dead on center bull im talking about.

 

[sestoppelman]

Ignorant question about the double rifle. If the center to center distance between the bores at breech is say a theoretical 3 inches, and the c-c distance at muzzle is say 2.5" that means the distance is closing correct? If that is so and I don't know that it is. .will not that make the bullets converge or cross at some point? This of course assumes a closing gap. Now if the c-c distance is the same at breech and muzzle, that makes sense that they would or should remain parallel. Not looking for trouble, just trying to understand this theory of the bullets never converging. If I remember correctly the guru opined in his book that at some point it seemed logical that the bullets would converge at some distant point, even in a properly regulated rifle. Infinity is a heck of a long ways away.

 

[johneracer]

That might be true if the rifle was locked in and not allowed to recoil. As the bullet starts to travel down the barrel, muzzle will rise and move to the side being fired so it is very possible to get a double to shoot parallel. That is why in shooting consistency in holding the rifle is the key

 

[sestoppelman]

The amount of recoil rise or torque from shot to shot while being hand held by a human, would vary so much as to make that equation basically random, and therefore moot I should think.

 

[johneracer]

Not to get into a pissing contest but although you are correct, this is a proven concept and all manufacturers account for it. The amount of muzzle movement is extremely small so the difference in shooters is negligible to achieve the desired effect. Yes all shooter will hit a slightly different spot due to the way they hold the rifle, their mass, etc,,,but accounting for shooters error, this is hardly noticeable, especially at 50 yards.

 

[johneracer]

It would be interesting to use trigonometry and calculate muzzle movement needed to shift the poi at 100 yards....

 

[sestoppelman]

I would agree, especially at 50 yds, but a previous post was talking about infinity. Here is another question then. Since I don't have any doubles in the stable to look at, is the c-c distance the same at muzzle and breech on most, any or all doubles? Seems to me there must be a difference due to the barrel and chamber thickness at breech as opposed to the muzzle where there is usually a lot less metal. That was my point earlier because there is a closing of the c-c distance from one end to the other and so in theory the line of bore will converge at some point, certainly some distance off, but eventually it should have to, wouldn't it? That's why I cant quite wrap my feeble noggin' around parallel to infinity. Perhaps its done with opposing twists, figuring out the rotation or something? I guess that's why they get the big bucks!

 

[johneracer]

If the muzzle barrel distance is one inch and rifle shoots one inch at 50, then we are good to Infiniti? But 99.9% chance is a double will converge or spread at a distance so it is a mute point. It would be really really hard to make a double shoot parallel. It might be 200 yards, or a 1000 but chance is it will not be parallel.

 

[johneracer]

To answer your question, my double is 2 inches at the breech and about 1.5 at the muzzle. My understanding is that the barrels are soldered flat parallel at the mono block so the case is on the face, then the barrels are squeezed together to converge. This is a common way to make doubles. Barrels are bent in and soldered. Good stuff

 

[sestoppelman]

If the muzzle barrel distance is one inch and rifle shoots one inch at 50, then we are good to Infiniti? But 99.9% chance is a double will converge or spread at a distance so it is a mute point. It would be really really hard to make a double shoot parallel. It might be 200 yards, or a 1000 but chance is it will not be parallel.

That would be my understanding as well. Thanks.

 

[edward]

does all this crap really mean anything???shoot the gun on paper.that will show you where the bullet is going to go out of the right barrel and left.period.theory and anything else is just so much bullshit.

 

[Rolf_T]

In my 470ne double, when shooting at 100meters, the bullets cross with about 15cm with the same height. At 50m they are in a better group...
This shooting a-frames which the gun was not regulated for...
Paper gives the answers as edvard states in above post

 

[sestoppelman]

does all this crap really mean anything???shoot the gun on paper.that will show you where the bullet is going to go out of the right barrel and left.period.theory and anything else is just so much bullshit.

Wonderful contribution to an otherwise civil conversation. Thank you.