When working up a load, all you are concerned about is group size. NOT ITS LOCATION. It can be a foot high, and foot left, but if its a good group, you can deal with it.
When you work up loads, for two barrels, you have two separate barrels, each requiring perhaps a different combination of bullets, or ball diameters, patch thickness, and choices of lube to shoot the smallest group SOMEPLACE. It really doesn't matter at that point where the group hits.
The Scope allows you to minimize human errors that open up group size.Period. Its done its job when you have the best load for each of the barrels.
Take it off, now.
NOW, adjust those two leaf sights, one for each barrel, to bring the groups over to some semblance of POA. Do this first at 10 yds. I find that I can get my windage and most elevation problems corrected, with both iron and scope sights, at this short distance. The Windage problems are the ones that drive me nuts at 50 yards and further If I am still having them. Elevation can be cured with the judicious use of a file, on most guns.
Now, whether its even possible to regulate those two barrels to shoot close to each other at ANY distance is an unknown. But, you get there by first working up accurate loads for each barrel, then zeroing the sights, as close as you can get them, and then regulate the barrels further to bring the groups to the same POI.
I learned all this years ago helping a friend attempt to get both barrels on his 12 ga. DB, sxs shotgun to shoot slugs to the same POI. After weeks of testing every brand of slug available, he found he could get reasonably close if he loaded one brand in one barrel, and another brand in the second barrel. Talk about unexpected results! :shocked2: :youcrazy: :blah: :idunno:
But he was happy, so he could take that gun deer hunting the next month. :surrender: :thumbsup:
I have not seen it done with Rifle barrels, but have seen it done to regulate DB shotgun barrels a lot.I am talking about bending barrels, or filing the muzzles on one side or another to change how the ball or bullet releases at the muzzle, to affect its POI. I can't think of any reason why this would not help regulate a MLing DB SxS rifle. :hmm: