I can tell you I had no trouble smashing skeets with the 1760 era Griffin I had the chance to shoot. I would assume they need to be pinched together somewhere around the midway point so the bores are parallel for a short distance. If you have to remove some material in that area I'd do it. (with a file)
All my old SXS flint shotguns shot to point of aim.
There will be no problem busting clays with it now Mike. I did file the flats. Read on to hear all about it.
As mentioned in the previous post it was stated that, “as they sit now the barrels can not be regulated to standard distance” and that i would not file adjoining flats more to make ‘em fit closer. While the first part was a true statement, i made myself a liar concerning the second part. After much deliberation it was back to the shaping jig for some judicious hand filing and fitting. An additional 0.005” was removed from each flat then it was back to bore sighting. Knowing a total 0.010” was not enough to make up the difference, a tapered wood shim was inserted between the barrels at the muzzle:
Gap between barrels was adjusted by moving the shim up and down. Convergent point was checked at 12 and 25 yards by trial and error until there was convergence at 25 yards. Final shim setting at 12 yards:
And at 25 yards:
Weak batteries in the bore sights and broad daylight make for a less than perfect image but still it’s not a good idea to look the lasers in the eye even at 25 yards:
Gap between the barrels was measured and as it turned out, we need a 0.062” shim at the muzzle to attain convergence at 25 yards. Armed with this new data, it was back to the shop to make the shim but not sure i will use this particular part:
It fits between the barrels at the muzzle like this:
It also functions as the loading rod keeper:
So, it took 0.072” total correction to make the barrels converge at 25 yards, which is pretty dang close to Bob W’s calculated 0.062” correction:
Hank, another way to look at this is the center bore to center bore, setup so they are exactly the same at the breech and muzzle, in theory should hit at that point and spread at 25 yards. If that is 2 inches you need 1 inch correction at 25 yard on each barrel. Thats .062 total or .031 on each barrel. If I’m thinking correctly on this, it should have been fairly easy to calculate while making the barrels.
Bob, it was calculated prior to making the barrels using bore center line reference. Had the barrels been made to exact specifications regulating would have been much simpler. However, much of the shaping was done by hand causing considerable deviation from specified dimensions. Oh, wall thickness at the breech after removing the additional 0.005” measures 0.206” left, 0.200” right at the minimum of both barrels.
I think Mike Brooks opinion from a month ago about a whole herd of craftspeople is probably right and Mr.Bailes was an agent/contractor.
A pair of locks then would have probably been expensive but I have no idea about real cost.Lynton McKenzie told me that a pair of high end flintlocks could take the entire salary of a degreed teacher at a university.THAT would never be accepted here in the "colonies"at any point in time.I used to get requests from time to time for pairs of locks and used the L&R externals and 2 sets of Mantons which were made in moulds using the antique locks as masters and it took a good bit of time to get the Mantons to the point where locks could be started and
the mechanisms that make them useful had to be fabricated and that was labor intensive and I hope good locks can be found or made for this job.
Bob Roller
Not to worry Bob. We'll use only the best parts to make the locks no matter if store bought or hand made. Too much pride in quality and workmanship to let anything else happen.
This is new territory to me -first time making barrels, first time joining and regulating barrels to make a set. I have built many SxS double flints but with barrels from junk breech loaders that were already joined, and presumably, properly regulated. I’m learning a lot and still have a lot yet to learn but i’m having tons of fun with this project in the meantime. We're gonna build it!
Hank