Beckmann Tuner Info Please!

[Riverine]

Frank,

Congrats on on putting together such an accurate BRX and shooting it so well in four successive matches. I guess there's hope for some of us VN vets after all.

I'm intrigued by your Forearm-fitted tuning gizmo. I have a Rem .260 that strings vertically sometimes. It looks like your system might be worth a try.

1. How exactly is in adjusted? Maybe I missed something but do you have index marks or something?

2. Does the Delrin washer hold steady pressure over time, or do you have to tweak it now and then?

3. By "a little pressure", what are we talking about--just touching or a few lbs of pre-load?

Thanks again for the article. Interesting stuff. I suspect though, the grandkids won't get "first Dibs" quite yet.

 

[LongRanger]

1. How exactly is it adjusted? Maybe I missed something but do you have index marks or something?

2. Does the Delrin washer hold steady pressure over time, or do you have to tweak it now and then?

3. By "a little pressure", what are we talking about--just touching or a few lbs of pre-load?


Riverine, once the "tuner" is made and in place, it is necessary to index one end of one of cross slots in the bolt head to a reference point on the underneath of the stock. I did this by first bolting the barreled action back into the stock. I then placed a piece of the thinnest, but strong, paper I could find in the house...about .0015"...between the delrin washer and the barrel and turned the tuner bolt so as to bear the delrin washer against the paper enough so that it causes reasonable,paper just barely slides) resistance when I try to pull the paper out. I then "assume" that the washer would be just touching the barrel without the paper. I then looked at the bottom of the stock and picked the end of one slot and called it 12 o'clock and marked it and the corresonding location on the stock with a liquid white-out pen. With additional white marks on the stock at 3, 6 and 9 o'clock I figured my eye could interpolate the remaining points of the clock.

Note that using a phillips head bolt and a phillips screwdriver like I did is crude but effective. Use an allen head bolt if you can accept a somewhat larger hole in your stock. Then a turn of the bolt with the allen wrench will yield you a finer discernment of how much you move the bolt in relation to a clock face.

I don't know how long the "tuner" will hold adjustment and didn't have to tweak it when I used it. I selected delrin plastic because it is tough and not likely to crush under slight, vibrating pressure. I elected to cast the bolt in epoxy doped into the drilled hole through the stock rather than put it in a threaded sleeve since I know that the resulting tight thread fit plus the "somewhat sticky" plastic nature of the cured epoxy would keep the bolt from turning while shooting.

By "little" pressure I mean only to the point where I can begin to sense some resistance....using a phillips driver with no handle. I used the setting I got when I indexed the tuner bolt and stock as my "little pressure" point. My groups from this point through 3-4 more slight changes until I had turned the bolt in only 1/4 turn made significant changes in vertical points of impact and group sizes.

The "tuner" build is kept fairly simple by using this method of casting the tuner bolt in JB Weld slow set,normal)epoxy. If one makes a mistake, just drill out the epoxy and re-cast the bolt.

I kept some of the targets I shot with the tuner. These show changes in vertical location of the groups and changes in group size. If they photograph well enough, Paul may show them on the site.

Frank