Loading for double rifle

[Licensed to kill]

Anyone work up loads for a double rifle? Wondering what is the most efficient way to go about it. Im thinking to load and test from one barrel until I get a load that I like then try it in the other barrel. Typically, one would adjust POI through powder charge but that creates a lot of variables that I have trouble wrapping my head around mitigating. A buddy knew a guy in Britain that had quite a lot of experience with double rifles and he would work up a load for one barrel and when he found a load that works in that one barrel, he would try it in the other. If it did not print how and where he wanted, he would work up a load for that barrel. He would then mark the primers with a marker indicating right or left barrel. What “process of elimination” tactics have others used?

 

[guntech]

Accuracy does not have to be great in a double rifle. The ranges are relatively close and usually off hand shooting. If the barrels are printing a 3 inch group at 50 yards it would suffice.

 

[iron cat]

Not sure about other manufacturers, but FAIR regulates their barrels SXS and O/U rifles for accuracy of 50MM at 50 yards with open sights.
Cat

 

[257hunter]

I am by no means an expert but from my understanding doubles are generally a matter of x bullet weight at x velocity to match whatever it was regulated for. The different pressure curves of different powders can make a difference. You are not trying to achieve the same level of accuracy we have become accustomed to with modern bolt rifles.

If you’re into podcasts at all episode 378 of the big game hunting podcast discusses regulation and loading a bit.

 

[mbatten]

Get this book:

Shooting the British Double Rifle by Graeme Wright, Fourth Edition​

 

[iron cat]

I am by no means an expert but from my understanding doubles are generally a matter of x bullet weight at x velocity to match whatever it was regulated for. The different pressure curves of different powders can make a difference. You are not trying to achieve the same level of accuracy we have become accustomed to with modern bolt rifles.

If you’re into podcasts at all episode 378 of the big game hunting podcast discusses regulation and loading a bit.

Yeah the FAIR rifle come with the information on the factory cartridge used, in the 6.5X55 it was a 140 grain RWS and in the 9.3X74R it's a 286 RWS IIRC.
Cat

 

[Longwalker]

You will be disappointed if you try your "one barrel first" method. The usual method is not about the accuracy per barrel, it's about the proper convergence of the barrels at a given range. The book by Graeme Wright is the best I've read on the subject. He covers all the traditional / historical and modern double rifle cartridges and exactly how to develop loads for them. I used the book to successfully work up proper loads for my Merkel 140 AE in .450-400 3" Nitro Express. It is a detailed, meticulous process, in my opinion way too much info to properly convey in a post here. Short version: You must choose the proper bullet weight and profile, and powder of the correct charge weight and burn rate, and vary the powder charges a little at a time till both barrels shoot to the same point and with acceptable accuracy.

After going through the process that Wright describes, I was satisfied. My handloads shot better than the factory loads the rifle was regulated with, and I could do that with better quality bullets too. I went on to use my double on a couple of successful hunts for Cape Buffalo in Namibia and Mozambique. I recently sold that rifle, so my copy of Shooting the British Double Rifle is for sale if you're interested.

 

[track]

I still own one sxs double rifle, Merkel model 141.1. My first double was a Blaser S2. These two rifles have one main thing in common, "they can be self regulated." Load development was most easy. Shoot one barrel and then regulate the other barrel to shoot POI as the first.

I had both shooting the same POI at 100 yards. Blaser no longer manufactaures their double rifle however, a used one can be located. Merkel and Chapuis still manufacture the self regulated double. For me, this was key when purchasing a double and not at the mercy of factory regulated.

No, I had no intentions to hunt Africa, it was to hunt in my own province. I'm still entertaining the idea to purchase another double, then I'll have a double double. LOL!!!

 

[209jones]

Best advice I can give you on loading for a DR is look up posts by MacD37 on Accurate Reloading, he also posted on Africa Hunting under Dugaboy 1 IIRC, and Graeme Wright's book is worthwhile. DR's do not work like other guns to load for, simply because you have the two barrels joined to each other. Even knowing what ammo it was regulated for may not help if you can't get that lot nbr, in which case you have to try to match it. Even with adj regulation, you have to reach a starting point to work with, before adjusting it. Developing a load for one barrel, could easily not work on the other, in which case you may just have a singleshot DR.

 

[jeff270]

Get this book:

Shooting the British Double Rifle by Graeme Wright, Fourth Edition​

Great book

 

[Mr.Rigpig]

 

[Neo]

Get this book:

Shooting the British Double Rifle by Graeme Wright, Fourth Edition​

100% agree. In fact, don't bother even starting to develop a load until you've read that book from cover to cover.

I can honestly say that Wright's advice was spot on. What you're chasing is a load that replicates the muzzle velocity of the old Kynoch loadings in whatever cartridge you're shooting -- with IMR-4831 being the go-to powder in the vast majority of cases. In the Merkel 450-400 I was loading for, the process was dead easy. A charge of 80 grains over a magnum primer and pushing a 400 grain bullet, and I was able to consistently put 4 shots (2 from each barrel) into a 2-1/2" group at 100 yards. Not a lot of fun to shoot from the bench, but once that load was found there was never a need to bench the rifle again. It's funny though how it felt like a pop gun when shooting at a buffalo or elephant

 

[brybenn]

I chose a bullet and worked up 4 rounds of each load thru the powder chart
2 shots from each barrel. I took the powder charge that grouped closest to poa. Then worked within that bracket playing with seating depth. My rifle is horizontal adjustable so I only had to worry about vertical spread.
That's been my method right or wrong