Regulating my double rifle

[Leatherman]

OK I finally got my Collath shooting again. Had to make a new main spring. I also installed a rear claw mount base and made some claw bases for a little German scope I had. I started with the 46 grains of VV N140 Axel recommended and the barrels shot about 4" apart at 50 yards and about 4" high. So I upped the load another grain and went out today to see if there was any change. I decided to use Dacron filler to fill the empty space. Attached is my target shot at 50 yards. I have color coded the right and left barrel shots. They are still shooting apart and high but it looks promising. I do not shoot open sights well by the way. That is why I like scoped rifles. I have listed the velocities on the right side of the target and am not impressed with the variations. I got velocities from 1723 to 2148 fps.it appears that the few higher velocity shots grouped closer together so I am hoping that if I can get closer velocity spread and get it up to 2100 or 2200 fps , it should regulate well at 50 yards at least. I shot the first 5 two shot groups with open sights. I then attached the scope and shot #6 right and left still useing the open sight to see what effect the added weight of the scope would have on the point of aim and group. I then did a quick zero of the scope and shot # 7 two shot group useing the scope and as you can see they were only about 1 1/2" apart and about 2" higher than the previous groups with out the scope attached but still centered. This is looking very good so far as I will hunt with the scope attached. So I need to figure out what it will take to get a more consistent velocity out of this cartridge. I know we have had discussions on different fillers to use and possibly a different powder will also help. I am getting close to the end of my Buffalo Arms Tesco 193 grn bullets and then I'm done until they get around to making more. I am going to call them and rattle their cage about these bullets we need. I have some 200 grn lead cast bullets I am going to try after I get it shooting with the jacketed bullet. Anyone have a possible cure? image.jpg
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[Leatherman]

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Hopefully this is a bigger photo
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[mike ford]

Leatherman,
It looks like you are making a good bit of progress. I agree with you about the variation in velocity. I'm surprised the dacron didn't fix the problem. I have good results with kapok tamped down over the powder. Dacron acts similar to kapok (I recognize some think that is the wrong way to do it, but it has worked for me). You may try a different filler, such as open cell foam, backer rod, or one of the others. You might also try one of the 5744s. My experience with this powder has been limited to cast bullets, but it should work with jacketed also. This powder is marketed for use in large cases with out filler, but I think sometimes filler may help, even with it. For loads you could talk to the powder company. Could you refresh my memory, what is the groove diameter of your barrels?
Mike

[Diz]

Leatherman,

I could only read four velocity numbers for the left barrel and at first glance it looks like a sizable spread. It also looks like the right barrel is going faster but if you run the mean the left is 1802 fps and the right is 1990 fps for a 188 fps difference between the two sides. That is averaging four and six velocities and it really should be an equal number of samples for both. The interesting number is the SD. I calculate the left at 61.7 fps and the right at 183.8 fps. Now that shows a difference.

I also ran that load using a 24" barrel and 193 grain RWS bullet. I guessed the barrel length but here's what came out:

PMax 25906 psi
Fill 81.7%
Vel 2207 fps
Burn 90.87%
BalEff 25.5%

So the actual velocity is a bit low against calculated but I think pretty close to factory. Mike is right about fillers and another may make a difference but I would check all the usual things as well related to cases, bullet seating, pull and etc. I use this powder and like it. I might be inclined to check the bore diameters very carefully to see if there is any difference between the two sides. Just thought I would put in my two cents.

Thanks, Diz

[Leatherman]

5744 powder is my next step. I have two pounds of it. I have heard great things about it in straight walled large cartridges that originally were black powder. Problem is Accurate does not publish load data for this powder in old Black powder cartridges. They mention in their website it is a great substitute for black powder cartridges but don't have the data. They do seem to push their 209 black powder substitute and offer data for a few of the old cartridges like 45-70 and larger. I might try this in my 11.3 X 83 double rifle. I am going to the Shot Show the end of this month in Vegas and I will stop by the Accurate Powder booth and will find out how to get starting loads for their 209 and 5744 in cartridges like 9.3x72,80,82 and some of the larger calibers as well. As far as fillers go Accurate states in their litature not to use a filler with 5744. It is a progressive burning powder with low ignition temperature . I will discuss this with them as well. I hope to come back with some good information for the forum members who reload.
Diz, I noticed the right barrel gave a little faster velocity too. I had some errors on my chronograph so that is why I don't have all the figures. In the book shooting the British Double Rifle , it mentions some well used guns occasionally have the right barrel worn more and as a result the velocities vary between them. Now I don't think this rifle has been shot that much but it is worth a look. I did a cast of one of the bores when I first got it and it came out to .364". I definitely have a lot of shooting ahead of me .

[Diz]

Leatherman,

I would be very interested in what Accurate had to say about this so please post what you find out and info from any others as well. I would check the bores and then you will know for sure.

Safe travels, Diz

[mike ford]

Leatherman,
My cousin uses 5744 in his 9.3x72R with a 250gr cast bullet. As I recall, he uses around 28 gr. Of course, this is not definitive, but gives some idea of where to start. Accurate's statement to not use a filler is because a major selling point is that it is usually not necessary. You have to decide for yourself how much variation in velocity you can tolerate.

[Leatherman]

I really think the least variation in velocity is going to be the biggest factor in getting a double rifle to regulate as the velocity is the biggest factor along with the weight of the bullet. So I will discuss useing a filler with Accurate at the show. Mike, does your cousin use a filler with 5744? I will get back with what Accurate says and with my results.

[mike ford]

Leatherman,
No, he does not use a filler. He has an acceptable velocity variation, but I believe he could have less with Kapok. His load is used in a single shot rifle, which is an entirely different case than yours. Since you seem to have significant difference in velocity between the barrels, if anyone suggests a different load for each barrel, you should resist this. You may be able to have closer groups, but in the excitement of the "chase" the chance is too great that different loads get loaded into the wrong barrel.
Mike

[Leatherman]

I am following up on this thread as I said I would be talking to Accurate powder at the shot show to see if hey could help me with starting loads on my 9.3x80 Collath and some of my other German cartridges. Well at the show the gentleman in charge of developeing the load data was there and he said he would help me and to email him the calibers and the specs on them. So when I got back I sent him specs on 9.3x72 , 9.3x80 and my 10.15x83. He emediately sent me an email back saying my wildcat cartridges were too wild for his liability concerns. So I think he was told not to give me any data from someone higher up. So I am going to start with around 29 grains of 5744 in my 9.3x80 Collath and see what velocity I get and see if the spread In velocities is closer with 5744. On my 10.15x83 I will stick with black powder as it was made for. I really want to get this one shooting too.

[mike ford]

Leatherman,
Did you get your problem with a source for jacketed bullets sorted out? Diz has talked about bumping up .358" bullets, 200 grain bullets should be close enough to 193 grains to work. This is not my project, and I understand I don't have a say in how it's done. That said, I don't have good results with double and combination guns, using the equipment and procedure the photos seem to show. I find I have to shoot from sandbags, stacked up high enough that I must sit up more or less straight, to move with recoil in a manner similar to shooting in the field. Also, I only have satisfactory results if I hold the rifle in my hands, with my hand or wrist, rather than the rifle, resting on the bag. It's not that I don't use mechanical rests, at all, I do often find a lead sled helpful, just not here. It is not possible for me to shoot the second barrel quickly enough, if I stop to locate the first shot's impact. This is especially so if I take time to note the velocities. The only way I can get satisfactory results is to work out the variation in velocity ahead of checking for "regulation"(I admit I haven't had to contend with such variation between the barrels), and shoot two targets, one for each barrel. I shoot the first one, then the second, just as quickly as I can align the sights(or scope). I have to allow the barrels to cool to ambient temperature before the next two shots. Once the shooting is done, I can lay one target on the other and mark the bullet impact. This is the only way I can easily tell if the barrels are shooting "wide", crossing, or shooting together; with the load I'm checking. I know we don't hunt that way, it takes much more time, it takes more ammo, and my friends think I'm silly. I think I need to separate the ammo problems from the rifle problems, from the "me" problems; so I can work out solutions. If you get good results otherwise, good for you.
I'm interested in the outcome of your experiments with 5744 and jacketed bullets, with different fillers.
Mike

[Diz]

Leatherman,

Mike has a lot of good advice regarding shooting the double rifle. My groups are better and more consistent when holding the gun in my hands rather than off the bags. The only comments I can make beyond that is the group seems to be trending to the right of center fairly evenly and a scope adjustment may be all you really need to center the group on the bull. However, the load does not seem to be working well with too much variation and it still looks like the right barrel is faster. I am wondering if throat erosion from the right barrel being normally shot more often could possibly be the cause by giving it more freebore. One thought on 5744 is that as you get close to 2150 fps in the 9.3x80R my program shows that you will only be a couple thousand pounds away from the CIP Max. That was with the RWS 193 grain jacketed bullet. Pardon me but it is a lot of speculation on my part.

Thanks, Diz

[Leatherman]

I have read in Shooting the English Double Rifle book that indeed the proper way to shoot a double is offhand and to quickly shoot the second barrel. This is my first rodeo with a double rifle so I have much to learn by reading, advise from others with experience and my own experience with what works for me and the gun. I only have the lead sled for shooting from the bench so I was supporting the forearm with my left hand. I also shot all but the last two shot group with open sights which I know has a margin of error as I just don't shoot open sights that much and as I stated the group with the scope attached was much better than the others, almost acceptable. I need to concentrate on getting a load that is more consistent in velocity and first shoot and check velocities in each barrel . THat will tell me if there is a consistent velocity difference between the left and right barrel. Once I determine if there is a difference between barrels I will be less critical of trying to get the rifle to regulate. This is a hunting gun foremost and if it doesn't shoot 3" or better spread at 50 yards then it will be sighted in for which ever barrel shoots the best group and that will be the barrel I will use. I have only ever shot more than once at a deer maybe twice in my life and I enjoy hunting with a couple of single shot rifles so I don't see me having to use the second barrel anyway and if I know where it shoots I can try to compensate. I would just like to try some other powders and maybe a new bullet. In my experience developeing a load for my modern guns the bullet was the biggest factor in getting the best accuracy and then the powder just fine tuned it . So rather than bump up a .358 bullet I am ordering some .364 200 grain bullets from Cobra bullets. I have used their bullet in two of my other Drillings that have under size bores and I got excellent accuracy. Diz, thanks for the heads up on the CIP max problem with 5744. I may need to look at another powder as well. I have only used 3031 in my 9.3 x72 Drillings and it gave me good results as long as I have a good crimp. Anyone have any other suggestions on another powder to try ?

[mike ford]

Leatherman,
Just a couple thoughts, since you have good results(I do too)with 3031, it seems to be a good choice, as would any similar burning rate powder, such as 4895(any version)4320,etc. Since I'm from the "old school", I often leave out of these suggested powders, more modern ones that may perform better than the ones I use. As an example the new "CFE" powders may address other potential problems. You should, at least, try the powders you use, have plenty of, and feel comfortable with. There is nothing "magic" about any of the powders I or others use. If you listen; your rifle will tell you what it wants. I don't think there is anything wrong with Cobra bullets, I just talk about "bumping up" or sizing other size bullets, because it's fun. I don't have any good reason to think so, but I believe your rifle was regulated at a distance more than 50 yards. I suspect you would be better off trying 80 and/or 100 meters. I suspect also that it was regulated/reregulated with a scope. This would be very good, and my suspicion is because you seemed to have better luck with the scope. You may have even better results if you try it at 80 or 100 meters.
Good luck.
Mike

[Diz]

Leatherman,

I spoke with Buffalo Arms yesterday and didn't get good news regarding the .366/193 grain bullets. The fellow told me possibly three months or more before they arrive. I kept my back order in place but will start working on alternatives. I beat the net for some and came up empty. I have a 200 grain mold and may start casting along with bumping up some .358's. Otherwise the only option seems to be factory ammo.

I couldn't find "Cobra bullets" either. I can't really add anything further as I am working up loads too and was waiting for those bullets to arrive. So much for that idea.

Thanks, Diz