| DUGABOY1 |
| (.400 member) |
| 26/09/06 08:28 AM |
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Re: Technical Q. on DR's
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In reply to:
I was wanting some technical info on Double Rifles (Not specific to any particular make, calibre etc) My understanding is that regulation of the barrels is where the art/science and cost comes in. Firstly, so as I'm not starting off with the wrong info, is regulation the aligning of the barrels so that at some point in space if a bullet is fired from each barrel simultaneously they would hyperthically collide?
The above statement is both right and wrong! By that I mean the regulation of the barrels is not the most of the expence of the building of a double rifle, though it is a major part. The hand fitting and stock makeing is where the"TIME" which is money is the major cost!
Your idea about the bullets colideing at some point if fired similtaniously, is true if both barrels could be fired EXACTLY similtaniously. because the rifle will recoil differently than when fired one barrel at a time. However, if they are fired one at a time, and the load is proper for the regulation built into the rifle they would not collide at any distance, and would not cross either. When fired one at a time the bullets fly paralell, to all practical ranges.
In reply to:
Assuming that is correct; is there an optimum distance that this should occur and if so is this dependant on a particular calibre and its designed use. Eg. a 470 nitro express might be regulated for 100m and a 375H&H for 200m?? Do the gun makers have standard distances for certain calibres and if so what are they?
It is not true, so that is out of the way! The regulated to "DISTANCE" has to do with the fileing in of the sights, only! The sights are aligned so the windage is set to point to the left/ right center of the composite group. Then only the elevation is filed into the first, of "STANDING" rear sight to it is dead on at the so-called regulation distance, as stated by the maker. If it has flip-ups for longer distances then they are filed in for the elevation needed for those distances, with no change in windage. If the load is proper for the rifle's regulation, then both barrels will form a composite group at each of those distances. IOW , shoot paralell!
In reply to:
My understanding is that load development also takes on a critical part of the equation. Did/do the famous/expensive gun makers (Rigby, Holland and Holland, Purdy Beretta etc. no offence to all the other fine gun makers I haven't mentioned) develop an optimum load for their rifles and if so do they publish this info or advise the client what it is, or is it up to the client to work this out for themselves?
Even today most common chamberings where factory ammo is available, the makers will regulate with a factory ammo that is most widely available. If it is not generally available, and he has to load it for the regulation of the rifle, then he will give that infromation to the customer. Or in some cases the customer can specify a load for the rifle to be regulated to, if it is within the pressure limits of the rifle.
In reply to:
I would imagine that like any other single barrel rifle, a double rifle performs better with one load than another. Actually, it must be more difficult to find this load for a DR as you are dealing with 2 seperate barrels.
This is true, and it applies to double rifles as well. Before any regulation is wasted the "IN THE WHITE" barrels are tested for consistancy, with each individule barrel with the load to be used. Occasionally, one barrel will not shoot the regulation ammo at all, or at least not acceptably, and that barrel may be changed out before further work is done on the regulation. The two, however, will never be exactly the same in group size, but must be accepted with in reasonable limits.
In reply to:
I know DR's are not designed for target shooting (this subject was brought up earlier) but you still don't want one barrel shooting totally different to the other. (once again, I guess this is where the expense comes in)
As my answer above, you are right that is part of the expence in a double rifle. However, double rifles are far more accurate than most think. I know long time double rifle owners who accept poor shooting loads simply because they think doubles are only good shortly off the end of the barrels. This is defintely not true! The flip up sights for down range were not put on the rifle for looks, if the rifle is loaded properly the rifle will shoot to those sights at those distances.
In reply to:
Anyhow I am hoping for some info and perhaps some good discussion might occur. If these questions have been asked before, I appologise. I haven't had the chance yet to review every post on this Wonderful site. Thanks to all those involved.
Duscussion is always better that the any crap fest tha happens sometimes on the net!
All of what I said above was really said b Marakai with fewer words, in a much better, and clearer verbage, but maybe I hit on something he might have missed, that will help you. In any event the only dumb question is one that isn't asked, but there are many dumb answers, I just hope mine wasn't the latter!
