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Sville
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DR cross-firing
      #193677 - 13/11/11 04:03 AM

Maybe there already is a post about this?

Anyway, I have a question about cross-firing DR. All DR are cross-firing more or less, and if its more its a problem. I wanted this week to change bullet weight from 286 gn to 232 gn in my 9,3x74R. Norma gave me load data min/max. I started just above min, and that was a disaster, I tried several loads that was heavier. They were not good at all. I was about to give up. Then I read that if a DR is cross-firing before the target point, you shall use less powder. The opposite if its cross-firing behind the target point. I went down under min, not much. My double started to shoot really good. The powder was N-203B and bullet Oryx 232 GN.
Is this correct??? Less powder when cross-firing before target....
//Staffan


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tinker
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Re: DR cross-firing [Re: Sville]
      #193678 - 13/11/11 04:51 AM

With the right load, no double rifle is cross-firing.

With the right load, every double rifle will shoot the barrels with parallel trajectories.

There are many factors within a load which you may tune.
There are double rifles which seem to defy many different attempts to achieve a load which shoots to proper regulation.

The double rifle which fails all attempts to get both barrels to shoot parallel trajectories needs to be re-regulated at the gunmaker.







Cheers
Tinker

--------------------
--Self-Appointed Colonel, DRSS--



"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...


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Sville
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Re: DR cross-firing [Re: tinker]
      #193680 - 13/11/11 06:01 AM

You are obviously right. But om what distance was the DR originally regulated. Isn´t that important to? And who knows that?
/S


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Sville
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Re: DR cross-firing [Re: Sville]
      #193681 - 13/11/11 06:04 AM

And a DR is regulated to a certain bullet and load. Maybe as in may case you dont want to re-regulate it everytime??? Because you would like to change between bullets.
/S


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tinker
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Re: DR cross-firing [Re: Sville]
      #193688 - 13/11/11 08:21 AM

Distance at regulation only accounts for elevation.
The sights are usually marked with distance.

The question of which bullet type or weight is usually answered by the conventional loading of the cartridge - and when it's not standard the rifle is sometimes marked with the proper load.
You might find some clues in the Proof-House marks too.

What rifle specifically are you discussing?

On the issue of different bullet types for the same rifle, some rifles and some calibers are more forgiving than others, also some rifles feature adjustable barrel regulation.



Cheers
Tinker

--------------------
--Self-Appointed Colonel, DRSS--



"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...


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DarylS
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Re: DR cross-firing [Re: Sville]
      #193690 - 13/11/11 08:30 AM

What Tinker said is true - a DR should theoretically shoot both barrels parallel - so that the sights would be true at whatever range the rifle was fired at.

The distance between the individual bore axis would be the distance between the individual bore's group centres.

I think that not many DR shoot thusly - but what a wonderful thing when they do.

To find if the gun is properly regulated one must shoot it to find out. When shooting, you will find if it diverges, crosses or whatever it does. In a perfect world, it will shoot perfectly parallel.

Changing bullet weights or powder charges or even just to a different powder can have an effect on the regulation of the rifle - you are in commmand. I undrstand that changing it's recoil pattern by using a slower burning or faster burning powder can change it's regulation.

Tinker is saying that if all attempts through load changing to get the rifle to shoot the barrels properly is in vain, the barrels must be re-regulated - not to re-regulate whenever you want to change bullet weights - that would be prohibitively expensive.

Sometimes, I understand, you can change bullet weights and get the barrels to shoot properly - sometimes not and thus you are stuck with the load the gun was made to shoot- whatever it is - or - have it regulated for the lighter bullet and be stuck with that one.

One of the advantages of a single barreled rifle over a double barreled rifle, is the single's ability to shoot accurately with a multitude of bullet weights- one merely sights for it - some doubles won't allow this - period - but - you can adjust powder and/or powder charges if you know what you are doing & use appropriate powders that safely allow down or up loading, and/or other bullet weights to find a load the rifle likes.

You are in control - sometimes.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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Sville
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Re: DR cross-firing [Re: DarylS]
      #193691 - 13/11/11 08:53 AM

My DR is 50 year old DR from Belgium. You can't find out the originally load. I sucedeed finding à load for 286 gn, now I was trying finding a load for 232 gn. And I think I did find à good one, 30-50 mm at 70 m. But my DR obviosly are cross-firing with wrong load. /Staffan

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500Nitro
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Re: DR cross-firing [Re: Sville]
      #193692 - 13/11/11 09:04 AM


sville

You seem to have a fixation on cross firing. DR's are not supposed to cross fire unless the load is wrong. just find the right load by slow, methodical reloading techniques and only changing ONE item or component at a time.

9.3 doubles are often the easiest to regulate with different bullet weights, but of course all DR's are an entity to themselves.

Their are plenty of load data out there for all bullet weights in the 9.3. no need to re invent the wheel. Just take your time.

Not too sure what range you are shooting at but suggest do all your shooting a 50 yards to start with - much easier to keep the same sight picture between shots.

And use a target where you are not trying to keep aim in the centre of a 8" black circle, it's much easier to aim at a white dot on a black circle.


1. Work out the load that works with 286gns but also, try to work out how sensitive your DR is to changes - be it small powder changes, small changes in bullet seating depth etc etc.

2. Then use EXISITING load data and try shooting some 232gn
Plenty of load data exists.


Also, I'd suggest you find out what velocity you are doing.
Try factory 232 and 286gn loads and if they regulate, at least you know what velocity works.

.


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DarylS
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Re: DR cross-firing [Re: 500Nitro]
      #193693 - 13/11/11 11:30 AM

The target's shape and colour, as .500 Nitro suggests, is vitally important to having a good sight picture & making good shots that give good information. A poor target will produce poor results that are not repeatable.

Also, 50 yards is a good range to shoot - I also suggest putting up 2 targets, side by side and shoot the left barrel at the left target, right barrel at the right target, or over on the right, under on the left. That was you'll be able to see exactly what is happening.

A 1" diameter white dot in the centre of a black square or disk makes for a good aiming point.

Also if you go to www.targetz.com - there are a lot of different targets that can be downloaded and printed off. Click on TARGETS, then down the page to target # 10142 as described below, is a good one for 50 yard shooting with a bead.

Concentric 1" wide black rings, 1" apart on a white background makes a good target for bead front sights as the bead is easily centred inside the next larger ring.

Measure the distance between your two barrel's centres so you'll be able to judge if the barrels are crossing or diverging their groups. Measure from the centre of a 3 to 5 shto group (each barrel) 1 or two shots is usually not enough to judge by. You should use at least 3 shots out of each barrel to get a good idea of how that load is shooting, accuracy wise as well as regulation wise.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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Sville
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Re: DR cross-firing [Re: DarylS]
      #193708 - 13/11/11 05:16 PM

I am grateful for the input. //S

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NitroXAdministrator
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Re: DR cross-firing [Re: Sville]
      #193709 - 13/11/11 05:25 PM

Quote:

Then I read that if a DR is cross-firing before the target point, you shall use less powder. The opposite if its cross-firing behind the target point. I went down under min, not much. My double started to shoot really good. ... Less powder when cross-firing before target....
//Staffan




IN THEORY ...

If the load is crossing, ie the Left barrel impacts to the Right, and the Right barrel to the Left, decrease velocity.

If the barrels are printing apart, ie Right well to the Right and Left well to the Left, increase velocity to move the impacts closer together.

Of course trial and error may play a part, and the bullet weight, type etc may need to be changed as well. Or a particular load may never regulate well. A rifle may also need to be re-regulated too.

Ideally at the set distance each barrel's impact should be parallel to each other.

For an under and over, of course the line is vertical not horizontal.

IF THIS IS INCORRECT SOMEONE PLEASE CORRECT ME.


--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"


Edited by NitroX (14/11/11 01:16 AM)


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CptCurlAdministrator
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Re: DR cross-firing [Re: NitroX]
      #193728 - 14/11/11 12:01 AM

It sounds to me the trouble is with the lighter bullet. If the rifle handles 286 grain bullets properly it is likely to cross with the lighter bullet.

You cannot expect to make a radical change in bullet weight and maintain good regulation. Stick with the 286 or have the rifle re-regulated for the lighter bullet.

Curl

--------------------
RoscoeStephenson.com

YOUR DOUBLE RIFLE IS YOUR BEST FRIEND.



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NitroXAdministrator
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Re: DR cross-firing [Re: Sville]
      #193732 - 14/11/11 01:48 AM

Quote:

My double started to shoot really good. The powder was N-203B and bullet Oryx 232 GN.




From reading Staffan's first post, it looks to me, he found quite a reasonable load to shoot with the lighter bullet. (?)

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"


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tinker
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Re: DR cross-firing [Re: CptCurl]
      #193733 - 14/11/11 01:49 AM

Make sure the rifle's action is tight on the breech faces.

Also make sure that the head of the stock makes a tight fit with the action metal and that it is not soaked in oil and that there are no cracks in the head or wrist of the stock.

This is always good to know about any rifle, but these conditions will keep an otherwise well-regulated rifle from shooting properly.

Try to bend the wood up there by the action and look closely for movement, cracks, or signs of oil when you're pushing or pulling on it.
Anything but solid and tight fit needs to be repaired.





Cheers
Tinker

--------------------
--Self-Appointed Colonel, DRSS--



"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...


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Sville
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Re: DR cross-firing [Re: tinker]
      #193738 - 14/11/11 02:14 AM

I did find a really good load. Groups between 30 to 60 mm. But had to decrease velocity.
But all that you have written are very interesting and I have learned a lot. And can also be good help in the future. //S


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DarylS
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Re: DR cross-firing [Re: Sville]
      #193747 - 14/11/11 03:24 AM

John - you are right, of course - vertical dispersion with the overunder. I had side by side ingrained in my mind, even though I knew we were talking overunder. They are already on the same horizontal plane and if shooting parallel, should have individual barrel points of impact spread vertically as well - an instant 1" + height (or so) given to the top barrel's bullet. Crossing would have the top barrel shooting low and the bottom barrel shooting high.
The same 'rules' would apply though, as do with side by sides for spreading or bringing the groups together.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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DUGABOY1
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Re: DR cross-firing [Re: Sville]
      #196236 - 10/12/11 03:56 AM

………………..1779 words that are free for accepting or rejecting!

I believe that it is common in the USA that most folks think of a double rifle as either too expensive, or not suited to hunting anything smaller than an elephant, or both. Nothing could be farther from the truth.

The double rifle is the only rifle you can have that started its life as a hunting rifle. All other types started out as a war weapon, and then were applied to the hunting fields. Since it is the only true hunting rifle, that should be reason enough to attract hunters in the USA, but for some strange reason this has never happened.

I blame this on ignorance! Now before some of you guys get your feelings hurt, let me explain! Ignorance is nothing but a word that describes the fact that something is not well understood, or not known at all. It has nothing to do with a person's intelligence, but that he simply has not been taught something.

This phenomenon is not limited to the run of the mill hunter, or the guy who is not well up on "GUNOLOGY”, but is rampant among gun writers, and even some of the most well known rifle smiths in the USA, and many other countries. Even people who have taken the big five, and grand slams of all kinds are sadly ignorant when it comes to the double rifle. The misconceptions are a bag full that would slow a train to haul.

A double rifle can be made to shoot several different loads but it is not easy! The easiest thing is the regulating a double rifle to a known load at the factory. The hard part is finding a load that will shoot to the regulation that has been built into the rifle by the factory. That being said, to get the absolute best from any double rifle one needs to hand load, and once found the rifle will shoot properly with that load. What is needed is a pair of loads that will shoot to regulation with a soft and another with a solid to the same basic composite group. This takes some experimenting but once found you can take on just about anything on Earth with most of the chamberings that come in double rifles.

In the USA we tend to read the gun rag guys, as if we were reading from scripture, and anything they say has to be correct, simply because they said it. Again we are being misled, in some cases because the writer is too lazy to do the research, but mostly because they are printing opinion that they think is true. We all do that on occasion, it is only human because nobody knows everything. Still when it is put into print, by a self- proclaimed expert for the public to read it can lead the reader in the wrong direction. (some say this is what I am doing here but what I tell you can be verified quite easily)

The double rifle is a complex type of rifle to build and make shoot properly. No formula, or jig can be made to get away from the tedious work of fitting these things so they work properly. All types of things have been tried to make regulating the barrels easy, and nothing has worked. Most think if you simply make the barrel exactly parallel then the rifle will shoot side by side! So why not simply use a laser to align the barrels and save hours, and hours, plus several rounds of very expensive ammo to regulate the barrels? The reason is, it simply doesn’t work.

The barrels have to be laid to not only converge, but to point with the line of sight crossing, and low, compared to where you want the bullets to hit the target. The double rifle depends on the recoil arch (muzzle flip) of the rifle, and the speed of the bullet to shoot to where the sights are pointing when the trigger is pulled. IOW, if you place the barrels of a perfectly regulated double rifle in a vice with the sights held dead on your target at the iron sight' regulated distance, then with an empty case, with no primer, in each barrel using the primer hole like a peep sight, look through each barrel. What you will see is, the right barrel will be pointing at a place that is low and on the leftof where the sights are aligned. The leftbarrel will be pointing to a place on the rightand low in relation to where the sights are aligned. This is necessary because of thing called barrel time combined with recoil flip. What that means is, when the trigger is pulled on the RIGHTbarrel, the rifle rises up and to the RIGHT while the bullet is traveling down that barrel, so that the barrel is pointing to the point the sights were when the trigger was pulled, and Vice-versa for the left barrel. So the double rifle depends on the recoil arch, and the bullet's speed down the tube, to be aligned when that bullet exits the barrel. This converging of the barrels can be done exactly the same with two rifles shooting the same cartridge and they will not shoot the same, so each rifle has to be regulated by it's own rules to work properly. This is just one of the reasons even the cheapest quality double rifle requires over 800 to 1000 man hours of skilled labor to complete, hence the cost of manufacture. However when this is done properly no rifle in the world is more reliable for hunting anything from jackrabbit to elephant depending on the chambering.

The problem with the explanations for the way regulation works is two fold! #1 is the way the makers have always advertised their rifles. By this I mean when the maker says “THIS RIFLE IS REGULATED AT 50 yds or 100 yds!” people think this means the rifle crosses at that distance! That is not the case! This only means primary standing sight is cut to aim at dead center, of a composite group of both barrels for elevation, and windage at that range, nothing more. #2 Is because the barrels have to be slightly converging this and the makers statement about the sights seems to the unschooled to mean the rifle crosses at the sight’s regulated range. Both the reasons seem to be a no-brainer, but both assumptions are wrong, and not work that way!

Now we come to the smith who believes these two things and he may get the barrels to regulate when building a set of barrels but he seldom knows what he did to achieve it. So because he got one to work properly he assumes he has found the secret. My prediction is the next set he builds he will have a hassle with it as well, because he still believes the bullets from each barrel should hit the same hole at the distance he is regulating for. That DISTANCE has only to do with the way the sights are cut, and is done after the barrel regulation is completed. The reason for his thinking has made him confuse making all the bullets from each barrel make one large ragged hole at the range on the rear sight. The mistake he is making is that a regulator is looking for, not bullet holes to adjust, but the “CENTERS” of the INDIVIDUAL barrel’s four shot GROUPS that he wants to move to equal half the distances between bores on either side of the aiming point of the iron sights LEFT barrel GROUP CENTER on the LEFT of the aiming point and the RIGHT GROUP CENTER on the RIGHT of the aiming point, and both at the elevation of the aiming point of the sights .

To top this off the way these individual barrel four shot groups are come by is also most often done improperly as well even if the parallel concept is fully understood. In this case because a double rifle is a firearm that is to be used, firing the first shot from ambient temperature barrels set, with the second shot fired with a very short time after the first barrel being usually the right barrel, is fired, sort of a “ONE, TWO punch” from cool barrels. Because of this fact, to get a proper four shot group from each barrel to find the centers of each barrels group one must let the barrels cool to ambient temperature for each one two shots, one from each barrel till you get four from each barrel. Now you can find the centers of each barrels group, and these centers are what you want to move with adjustments not bullet holes! So now you begin to see some of the cost of building a double rifle when regulating the barrels, just to find the centers of the individual barrel groups has cost eight rounds of very costly ammo, and a lot of time, and this is simply to find the starting point to start the regulation!

Regulation and shooting by the owner are two entirely different things. However when regulating the rifle barrels, or finding a load that shoots to the regulates properly in those barrels the same four shot individual barrel groups must be properly found to load a proper load for a rifle that the regulation load is not known, just as it is with the factory regulator does with the cooling of the barrels properly to find the centers! Then speed up if shooting high and wide or slow down if shooting low, and crossing. The center of a barrel’s individual group should never cross over to the other side of the aiming point. As the groups of any barrel group with get wider at that groups goes down range so that as the groups of each barrel gets larger the RIGHT side of the LEFT barrel group will spill over into the other barrel’s group, but a properly regulated barrels set or proper load for that regulation the CENTERS will not cross. If it does then it is the shooter that is causing it to cross not the rifles regulation!

If you choose not to believe anything I have just written here that is your privilege, but that is the way a properly regulated double rifle was designed to work, and if it is fine with you that your rifle is crossing the individual barrel group centers, that is your privilege as well! I’m only the messenger, and I speak the truth it is up to you to decide if you want the message or not! After all it is free of charge.

................................. :wave: BYE!

--------------------
..........Mac >>>===(x)===>
DUGABOY1, and MacD37 founding member of DRSS www.doublerifleshooterssociety.com
"If I die today, I have had a life well spent, for I've been to see the Elephant, and smelled the smoke of Africa!"


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