If you read my last post, you know I believe I have found my accuracy problem. Inconsistent bore condition. I had planned to shoot my load over the chronograph and fine tune the powder charge but that did not happen. I lost over a month to life this year already. I did have a chance to make a few changes and tackle one very large problem I discovered.
In addition to using the lubed felt wad, I decided to try adding a hard card wad under the felt wad. I did this to gain a bit of scraping action on the bore, ensuring that the felt wad went down the bore undamaged. Sir Joseph seemed to think the scraping action was worthwhile and designed a wad stack that included small tin scrapers to that effect. I had a need to do some testing and decided to add the card wads to see if there would be any improvement. To my surprise, it did. While I was only shooting at 50 yards, I was able stack all shots into one hole. Pushing the felt wad down the bore was noticeably easier after the card wad was used as well.
Hard card wad, felt wad, and patched bullet.
Next, I was becoming frustrated at how my rear sight was mounted. I had tried several methods to avoid modifying the rifle and none were satisfactory. I had found the sight loose on several occasions and suspected it may have been the cause of more than one miss. I do not know what my aversion to modifying the rifle was, it is not a collectible rifle, not an original rifle, and not borrowed. Once I determined I needed a solid rear sight mount to do good shooting, a suitable mount plate was made in inlet into the stock.
Previous sight mount using a poor method of attaching to the tang screw.
New sight mounting method.
On installing the new mount plate, I was very careful to not only ensure the sight staff was perfectly vertical, but in alignment with the bore as well. The poor picture below shows, as best it can, the view through the peep with the barrel sight and front sight in alignment.
View through the sights with new rear mount.
And that brings me to the big problem. When I received the rifle, I test fired it one time to ensure that everything worked. Then, I mounted my tang adapter and the rear sight, packed for Oak Ridge, and shot the rifle in that condition. It was not until last year that I found a problem. Oak Ridge had a “Volunteer” class in 2018 using only the barrel sight and I planned to shoot the Whitworth in that configuration. I was shocked and surprised the first time I shot the rifle with the barrel sight only. The rifle shot over 6 minutes to the right. Reinstalling the tang sight and raising the barrel sight into view, I could see that they were not aligned. I had never checked that the tang sight was in alignment with the barrel. I simply mounted the tang adapter down the center of the tang and checked it for vertical.
This discovery started a search for answers that lasted several months. In re-reading my last post I noticed something that at the time escaped my attention. When I first went to Friendship to test the new loading method, I used the barrel sight and made good hits. When I returned the following weekend with the tang mounted sight I had to add 6 minutes of right windage to get hits. I did not have to hold off for wind using the barrel sight the previous weekend. There was certainly a 6 minute difference between the the POA and POI when using the barrel sight.
Talking to my wife about the possible causes, we remembered that the box was damaged on the muzzle end when the rifle was delivered. Inspection of the rifle showed no visible damage, so I did not find it concerning at the time. I now believe the package was dropped and the barrel bent. A long internet search on bent barrels, and correcting them, showed that it would take very little deflection in the barrel to effect a 6 minute change. I also learned it was not uncommon to see that happen and the solution was to bend the barrel back. Apparently, shotgunners bend barrels to change POI like I eat cookies.
I spent the next several weeks doing more research, measuring the barrel, calculating both the amount of correction I would need and how to best actually bend the barrel. In measuring the outside of the barrel, I could find no reference surface. While a hammer forged barrel may have a very precise interior, the outside of the barrel was anything but consistent. Close measurement of the barrel found it to be egg shaped and swamped. The difference was only a few thousandths, but it left me with no way to check the barrel’s straightness using the outside surface.
As the days passed, Oak Ridge 2019 came closer and closer. Eventually I would have to do something, so the decision to attempt bending the barrel was made. I made as simple a fixture as I could and tested the process several times. I used two hardened V blocks to hold the barrel and one wooden block to take the force of a bar clamp without marring the outside surface. I also setup a dial indicator to give me a rough idea of how much deflection I was putting onto the barrel. The positions of the barrel, blocks, and dial indicator were marked on the bench and all that remained was the courage to bend the barrel.
When the day came to make the attempt, I first fired two shots with the sights having no windage. Both bullets went into one hole, 7 minutes right of the target, at 50 yards. I then removed the barrel, installed it into the fixture pulling the barrel .5 inch. When the clamp was removed, the barrel now had .010″ of deflection. I again fired a shot at the target and the POI had moved left. HUZZAH! Two more bend and test fire efforts were made and the POI had moved over five minutes back towards center. A forth bend was made, this time deflecting the barrel 1.5″ and letting it rest for 5 minutes.
Barrel at full bend. 1.5″ of deflection.
When the clamp came off, I had a permanent deflection of .040″ in the barrel. Note that the dial indicator is moving backward from my zero.
Permanent deflection of .040″ measured.
To my complete amazement and joy, the final two shots went into one hole and were centered on the target.
At this point I wanted to make one more bend attempt at the same defection to possibly relieve any stress I had added to the barrel, so the barrel went back under the clamp a final time. I was feeling pretty good about myself at this point, as I had corrected the problem. So, when the wooden block shattered under the strain and the clamp let the barrel go, everything flew across the workbench and I nearly fainted. I did catch the barrel in mid air, but I have no memory of how I managed to do that.
A word of caution for anyone who attempts to bend their barrel as I have. Restrain the barrel and clamp, please. I was foolish for not doing so and while I have a funny story to tell about my misadventure, it could have cost me a broken bone or worse.
I now have a loading method that has been consistent with it’s results multiple times. I have a rear sight mount that is solid and repeatable. I have a barrel that shoots to point of aim. I will not have a chance to get proper sight settings before Oak Ridge this year, but I have a solid 500 yard setting and enough past data to get on paper at 300 and 600 yards.
So, in two weeks, we go to Oak Ridge and see if I can improve on my past performances. We go to competition with little to no practice. Into the fire…
vring 