Point of Impact

[paulvallandigham]

When guys in my gun club had rifles that shot to a different POI with the first shot, compared to the following shots, I found, working with them, that the problem related to a wrong ball size for the bore diameter, or the wrong patch thickness, or the wrong lube in the patch, or a combination of all three. The guys were relying on that first shot to dirty up the corners of their grooves in the bore to then accurately shoot following shots. When we measured the bore diameter, to a thousandths of an inch, then measure groove diameter and groove depth, and then chose a patch fabric that was thick enough to fill those grooves, and get down into the corners, the first shot hit the same POI as the following shots.

I did have one gun where the shooter failed to tighten his tang screw down, and the first shot fired to a different POI and the rest went elsewhere as the gun recoiled back and the screw was bound by the tang, fixing the tang and barrel in place for the subsequent shots. It turned out that this factory made gun had the tang and barrel mortises cut too deep, and we fixed the problem with some epoxy bedding compound. I also taught the owner how to do a check of all his screws after shooting, and cleaning the gun, and putting things back together, Without letting the GORILLA into his work shop to strip the wood in the stock, by tightening wood screws too tight. Later, he came back to me with a lock screw that kept backing out on him. I used a drop of lock-tite, on the screw threads, to fix that problem.

 

[longbow1]

I thought that it was the ball and patch combo ,Thanks.
I worked for a long time before I figgered it out but I was not going to step out to this forum and get my stuff stepped on . Thanks again