Double rifles?

[hounddog]

Kwilfong, by the looks of the target you are not in bad shape. I too have a cva 50 cal double rifle. First let the old gunsmith(me) clear the air. idealy all rifles should be perfectly square with the bore, Dont forget you also need a proper crown squared with the bore. The art of filing a bbl slightly off square works like this. Using kwilfongs target here is how I do it. First the gun is shooting low. adjust your sights to whereyou are hitting plumb center(up and down) at your selected range. Once you get the ellivation correct procede like this.look at your target. Yourleftbbl is what 3to4 inches left and the right is 3 to 4 inches to the right. Each bbl is grouping (thats good). eleevation is consistant but low. like I said fixyour elevation first. NOW the right bbl needs to print 3 to4 inches more o the left,at the 9 oclock position file the bbl slightly and test fire. the left bbl needs to go 3 to 4 inches to the right , at the 3 0clock position file slightly. How this works that slight filing allows the gasses from the charge to exit slightly before the rest of the bbl. this pushes your ball exactly OPPOSITE from where you filed. Even with blck powder your pressure is high, It does not take but just a little filing to make a noticeable difference. LISTEN UP NOW,,file a little and test fire to see results. go slow and take your time this is a trial and error method, but it does work how well depends on you. I am telling you all I have seen one stroke of the file be the difference in a good job or a medocre job. file a little shoot a lot. Yes you can do it. well I am sure that is clear as mud, I will follow the thead for futher comments if needed and wanted yours hounddog

 

Kevin,
What Houndog says is right on but you need to determine what distance you want the barrels regulated for. That's why I say shoot it at at least the 50 yard mark to see where it goes before you start filing.
Mark

 

[Lorne Johnson]

I know enough to know that Houndog process is the standard, but I haven't actually done it. Just where does one "file the barrel at 9:00"? Across the flat front or inside the muzzle (that would be inside the bore)? I'd want to be really clear on that.

I would also try at 50 yards as suggested, because they could start to come together (or, ugh, diverge).

I just read a post on another board, that part of what goes on in regulating doubles is recoil. Part of the recoil raises the point of impact (because the force of the recoil is above the shoulder). But, part of the recoil in a SxS moves the poi for the right barrel to the right and left to the left because each barrel is off the center line. This is likely a part of what you need to correct.

Good luck!

 

[kwilfong]

Thanks for the input guys!
I plan to do some load developement before doing anything with the crown(s).
My plan is to see what charge/patch/lube etc works best in both barrels individually & see if I get them together @ 50yards.
I have the capability to recrown if it becomes necessary.

 

[paulvallandigham]

60 grains of Swiss FFFg powder is a pretty hot load, don't you think? Have you used a chronograph on those shots, yet?

I don't think I would even attempt to regulate any double rifle without using my chronograph, BTW. It can be done, but about 10 times as much work.

May I suggest you begin with lighter loads- something close to 50 grains of GOEX FFg, not the hotter Swiss FFFg powder. The harmonics are pushing the two barrel groups away from the other barrel. That is Not unusual with Round Barrels, BTW. :hatsoff:

At least the two groups are parallel, so that you need to deal only with elevation problems to bring them up to your POA. Its a lot more trouble to deal with groups that strike at different elevations to your POA- one up, and one down, for instance.

 

[kwilfong]

Well; I thought 60gr was a fairly mild load but I will certainly heed your advice. I haven't chrono'd it yet.
I tried 70gr today & they spread apart more so lighter loads & FFg sounds logical.
Thanks again for the input!

 

[hounddog]

Fellas, I must agree with papa to first determine the distance you want the gun to zero to. I am going to guess about 75 yards is close to where it is regulated to. You need to shoot to determine where it is regulated to Before filing, you can then regulate to your preference. Gents I usually take a small fine cut round file( like a chainsaw file). You do not have to angle the complete bbl, just the hole where the bore is . determine where you need to file and just bevel it and test fire. Like I said in the earlier post file a little shoot often.NOw to twist the monkies tail, It is possible to regulate your bbls to different point of impacts. Example rt bbl at 50 yds, Left bbl at 100 yds. think on it might a good way to go yours hounddog

 

[tiger955]

I have been fascinated with double rifles for a long time, never owned one though, hope to someday. I have owned several double shotguns and one barrel usually has a tighter choke than the other, basically giving you a good pattern for long range or short depending on the barrel fired.
I have read much on regulating the barrels on double rifles and houndog's suggestion of having one sighted for close and one for long is intriguing, never thought of that, but it sounds like a good idea. :hatsoff: