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I understand that the barrels of a dr are mounted slightly convergent in order that at, some range, the bullet impact from both barrels coincide. If this is correct what is that range or does it vary with caliber? | ||
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Actually, the barrels are mounted as to allow for specific bullet at a specific velocity to hit as close as possible to the same point of aim/impact. Rusty We Band of Brothers! DRSS, NRA & SCI Life Member "I am rejoiced at my fate. Do not be uneasy about me, for I am with my friends." ----- David Crockett in his last letter (to his children), January 9th, 1836 "I will never forsake Texas and her cause. I am her son." ----- Jose Antonio Navarro, from Mexican Prison in 1841 "for I have sworn upon the altar of god eternal hostility against every form of tyranny over the mind of man." Thomas Jefferson Declaration of Arbroath April 6, 1320-“. . .It is not for glory, nor riches, nor honours that we are fighting, but for freedom - for that alone, which no honest man gives up but with life itself.” | |||
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Bryan, Theoretical perfect regulation has the bullets exiting the barrels parrallel to each other and never diverging or converging. A perfect two shot right and left group from a SxS rifle would appear as a figure 8 lying on its side with the distance between the right POI, which would be on the right side, and the left being the distance the barrels are apart at the muzzles. This would be true at 10yds, 50yds, 100yds or any range. Theoretical is theoretical and reality is reality so... Heavy rifles are often regulated at 50yds for English rifles and 60 meters for European rifles. Light rifles are often regulated at 100yds or 100 meters. In teory this shouldn't mater but... The greater the range the rifles are shot at, the more obvious the discrepency from theoretical perfect regulation becomes. A rifle and load combination that shoots well at 50yds will be a good foundation from which to tweak to shoot better when you extend the range to 100yds, no matter what range the rifle was regulated at. Hope this helps. JPK  Free 500grains | |||
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As near as I can tell none of the 3 double rifles I have ever cross fire with my loads. I have shot my 9,3x74R Chapuis at 300 yards on paper, it does not cross. DOUBLE RIFLE SHOOTERS SOCIETY | |||
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In my Merkel 9,3x74R the faster you drive the bullets the closer they get but haven't crossed so far - with max. 2600 achieved with 230gr. See also: https://forums.accuratereloading.com/eve/forums/a/tpc/f/760101804/m/572101804 | |||
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Thanks: these answers make more sense than my understanding(?) | |||
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Bryan, To make it clearer: If you were to set SxS DR barrels in a vice with the sights aimed at a target X yds distant, the right barrel will be pointing down and left of the POA of the sights if you were to look through the bore. The left barrel will be pointing down and right. Because the barrels are off center, the torque of recoil will have the right barrel recoiling up and right, in an arch. The left barrel will recoil up and left. The art of regulating new barrels to a given load is the art of fixing the barrels so that with a given bullet and a given velocity, and so barrel time, the bullets exit the respective barrels when the barrel is parrallel to the line of sight from the sights to the POA before recoil. Height is easily changed by altering front sight height or front sight and rear sight height if required. The art of finding a load that shoots to POA for a previuosly regulated rifle is the art of adjusting velocity, and so barrel time, for a given bullet weight so that the bullets leave the barrels when the barrels are parrallel to the line of sight of the sights before recoil from the shot. Again height is easily changed by front sight height changes. Too much velocity and the barrels do not have time to recoil far enough to have the bullets leaving when the barrels are parrallel to the original line of sight, so the bullets cross enroute to the target. The rifle will likely shoot low too, but this is less of an issue since sight height change can accomodate. Too little velocity and the barrels will have moved to far in their recoil arch and the bullets will leave the muzzles diverging from each other and the original line of sight to the target. The rifle will likely shoot high too. When velocity is right for bullets weight, the bullet will leave the respective barrel when the barrel is parrallel to the original line of sight to the target, this for both barrels. Any height adjustment is then made with a change in front sight height. Hope this helps JPK Free 500grains | |||
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When I first started reloading for my 9,3 Chapuis I tried using IMR 3031 and Speer 270 gr bullets as I had a lot of 3031 and the Speer 270's were dirt cheap. I already had my 2 British Big Bores and the 9,3 was going to be used for deer and pigs, plinking etc at the deer lease. ALL loads with 3031 crossed at 100 yards. I went to slower powders and the crossing stopped. DOUBLE RIFLE SHOOTERS SOCIETY | |||
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The misconception that the barrels are regulated to cross at any distance is common, though incorrect! The phrase: "REGULATED AT X number of YDS" Is in regard to the cutting of the sights, not the convergence of the barrels! The sights are regulated so the when the sights are lined up at that range, they are pointing at a point on the target that is the center of a composite group of both barrels at that range! The center of each barrel's individual group, with a proper load will be on it's own side of center of the composite group! IOW, parallel! In the building of a double rifle, there are "TWO" regulations! #1 is the proper convergence of the barrels so barrel time will place the barrels parallel when the bullets exit the muzzles, and #2 is the regulation of the sights to a given range of POINT BLANK impact in the center of the two barrel composite group. If you want an example of this look at a very well made double rifle, by a top maker that is fitted with multiple flip-up rear sights in addition to the standing rear sight. No matter the range the sights are cut for, the centerline of all those sights are in line for windage, and are only different in their height as the range gets longer. If the barrels were to cross at the so-called regulation range, then the down range sights couldn't be in line, and still work. People like H&H, and Purdy, don't put these sights on their rifles simply for looks, they work as cut, if the load is proper, regardless of which range sight you are using! Certainly nothing is perfect, but double rifles are not regulated to cross at any range! ....Mac >>>===(x)===> MacD37, ...and DUGABOY1 DRSS Charter member "If I die today, I've had a life well spent, for I've been to see the Elephant, and smelled the smoke of Africa!"~ME 1982 Hands of Old Elmer Keith  | |||
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I have loaded a couple of double rifles until they crossed, then backed of a few grains and they came back to a good group???? I have seen a few that would not cross no matter what you loaded them with but would not come together more than 3.5 inches or so..who knows what a double will do... One thing you have to take into consideration is barrel viberation, and that nothing in double rifle tech is written in stone. I have historically been the luckest double rifle owner in the world, all my doubles have been extraordinally accurate...Butch won the nationals with my .470, Rob Gunbuilder has Sweet Thang and she shot like a house afire, My Army Navy was a 2 inch gun on a bad day and my new Searcy cuts one hole and is an incher every time at 50 and 75 yds... I have never owned a minute of grapefruit gun and hope I never do.. Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
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I have been doing some 22lr shooting with 10/22 and very high mag scope. Under some conditions, I can see the bullet in the last half of its arc. The bullet is in a cork screwing right arc. I know that some of might light bolt guns do this. Does anyone know if double rifles do this? Kudude | |||
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I think all bullets take some distance to stabilize, but it isn’t enough to make any difference in where the bullet hits the target to any degree!  ....Mac >>>===(x)===> MacD37, ...and DUGABOY1 DRSS Charter member "If I die today, I've had a life well spent, for I've been to see the Elephant, and smelled the smoke of Africa!"~ME 1982 Hands of Old Elmer Keith | |||
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A question: Are bullet weight/type and velocity of the bullet from the specific barrel the key factors in attempting to duplicate a load to factory test target.And is bore tightness a factor. As i have shot and reloaded alot of .500NE Using all WR 1097 Ammo I have first hand tested and found that my Heym ran new at 2250-2275(tight bore and you feel it) , 2 New Kriegs ran at 2100-2125 with one having a consistant drop of 30 fps on the left barrel under the right barrel, 1 older Krieg my first with close to 300 shots in 10 years it run at 2050 religously. I ask because I always believe with any of the modern doubles the Velocity is the first thing I think a new owner should check with the factory loads and record them on your test target and to always have some on hand to sell with the rifle should you part with it. Does this matter or do I think to much. | |||
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Some good points 500pro, I don't think any factory ammo will regulate better that a well researched handload for a particular double rifle, even the ammo with which it was regulated! Going along with your take that ones should document the velocity, particular bullet, and make of brass, of a load, factory, or otherwise, that regulates in your rifle. Even the factory load that regulates well in your rifle, can often be improved by handloading. You are right the velocity should be determined, and recorded, along with the other things like brass, and bullet make! This load is then used as a benchmark, or starting point to be improved if possible, but at least equaled, in your handloads. To get the absolute best from your double rifle a few things are needed! The chronograph is No1, and a log to record everything you try for each double rifle you load for, leaving no item unrecorded. The proper brass care, trimming to uniform lengths, exact amounts of a particular type of powder, filler, if needed, and seating depth, and make of bullets, even the primer type. Once this is determined, a good supply of these items should be banked in your loading room, to avoid changes by makers of any of the components. Setting a couple hundred pieces of brass, several thousand primers, and several pounds of the powder, of all the same lot, if possible. Both loads of soft, and solids treated the same way in recording process. This insures you will have the very best ammo for that particular double rifle, when needed, and if that rifle is sold, this information should be copied, and given to the new owner, along with the rifle! When I get a new, to me, double rifle of a chambering I have owned before, I start with the best load I used in the earlier rifle, and adjust the load as needed to work best in the new rifle, I then lay in a supply, as stated above, and load 100 rounds in new brass, for a hunting supply. Any experimenting I do after that I use what I call practice brass, usually about 40 pieces. This lets me always have brand new ammo for hunting! Double rifles, new, or old, are a handloading affair to get the best from it, and to cut the very high cost of factory ammo, which is not as good, in most cases! This is part of the fun of owning, and hunting with a double rifle, the only firearm that was designed from the start, for only one purpose, HUNTING! All others started life as war weapons, or self-defense tools! The double rifle is the only true hunting from start to finish!  ....Mac >>>===(x)===> MacD37, ...and DUGABOY1 DRSS Charter member "If I die today, I've had a life well spent, for I've been to see the Elephant, and smelled the smoke of Africa!"~ME 1982 Hands of Old Elmer Keith | |||
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Thanks MacD37 from you I learn everday. Could we say that if someone claims a particular factory ammo load is running hot it is not nessasary the ammo but could be a little tighter bore on the specific rifle? I have many people discount there factory load because they have heard on the boards That WR Romey ammo runs hot, when in actuality it is the specific rifle barrel that is running tight. | |||
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If WR runs consitantly higher velocities in any rifle than, say, Kynoch ammo, the WR ammo is hotter. So, to determine if WR ammo is hotter than Kynoch ammo you would need to compare WR ammo against Kynoch or another brand, and not WR ammo in different rifles. Kynoch ammo is loaded to old British velocity standards and would be your benchmark. BTW, I have found powder selection to be critical, especially for cartridges which enjoy a wider selection of suitable powders. JPK Free 500grains | |||
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WRomey and Kynoch were average comparable in two rifles(kriegs)as I bought 50 rounds at the Reno auction in 2003. I chronoed 4 rounds in each rifle they seemed to avg.the same maybe 10 fps slower but not to the point I would call WR hot. As I have 20 left I will definately check these with some new WR coming in this year. Anybody compare the 2? | |||
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This could be absolutely true, but I'd lean toward what JPK had to say about useing both brands in the same rifle to be sure. The old saying "Where there is smoke, there is somtimes fire" and IMO, where there is a lot of smoke, the fire is almost a given! Pressure is an enemy of double rifles, and the least amount of risk you can muster, the better! Good luck, and enjoy the journey ! ....Mac >>>===(x)===> MacD37, ...and DUGABOY1 DRSS Charter member "If I die today, I've had a life well spent, for I've been to see the Elephant, and smelled the smoke of Africa!"~ME 1982 Hands of Old Elmer Keith | |||
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not my experience, .. as compared to an XY axis of center and level, the left barrel will be slightly left and more down, if you put a laser in it, and the right will be less down, more left ... assuming right had twist and right hand shooter... if the left barrel was right of center (poa has no real meaning at this point), it would hit way right.. the left barrel is UP and right under recoil, the right is RIGHT and up under recoil. what do i know, i've only bult 2, working on the third, and i am probably entirely wrong opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
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Free 500grains | |||
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 Jeffe, I would love to see the target you got with your barrels configured like that! ....Mac >>>===(x)===> MacD37, ...and DUGABOY1 DRSS Charter member "If I die today, I've had a life well spent, for I've been to see the Elephant, and smelled the smoke of Africa!"~ME 1982 Hands of Old Elmer Keith | |||
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If it were me I'd use a couple divining rods, a Hibachi, and a pipe wrench....... | |||
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FIRST outing FIRST attempt at regulation, shot standing with a monopod, 40 yards a 550 flanged .. left on the left, right on the right, and couldn't get enough adjustment that day to put them on the same plain.. "why so spread, jeffe?" BECAUSE I SET THEM LEVEL doesn't matter if you are lefty or righty, the barrel are going to rotate RIGHT .. ask Rob and John what their 600 OKs do at max loads... 40 yard, you can see every shot, i placed tape over the previous adjustment shots, every time... I don't remember what the $40 D was related to..  opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
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" If it were me I'd use a couple divining rods, a Hibachi and a pipewrench...." I like this guy, it almost seems there is a magical equation for each rifle built. As mentioned by another poster above vibration has alot to do with it as there is one heck of a pressure point the length of the barrels. Rodney. | |||
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One of the great gifts we have been blessed with is most double rifles shoot well when we get'um, otherwise this thread would blow through the roof and yes a devining rod would be the most helpfull tool in double gun history.. When it comes to doubles there is more rumor, inuendo, and BS floating around out there than there is in Hilery's bedroom.. Nothing is written in stone, but what you have been offered here is the best opinions IMO! Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
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