Search found 6 matches

by Jack Leslie
Sun Apr 09, 2006 7:31 pm
Forum: Shooters Lounge
Topic: 22 Match Ammo
Replies: 20
Views: 5746

Steve: No argument from me: I got the formulas from a 1965 book by a gentlemen named Frank Grubbs, a mathematician at Aberdeen Proving Grounds. I even found a reference at using RSD in testing the accuracy of the M1917 rifle. I make no claim to discovering these stats. I just used them and tried to ...
by Jack Leslie
Sun Apr 09, 2006 7:05 am
Forum: Shooters Lounge
Topic: 22 Match Ammo
Replies: 20
Views: 5746

I found that the radial standard deviation (square root of the sum of horizontal and vertical variance) was slightly better than the mean radius, but it was much more intense to calculate. I also found that the information content of additional shots diminished, and that by the time you have 25 data...
by Jack Leslie
Wed Oct 26, 2005 11:35 pm
Forum: Olympic Rifle - Air and Smallbore
Topic: Cheek piece adjustment
Replies: 12
Views: 5706

The point of the excercise is not to replace the rear sight, but to find the proper adjustments to get your head and eye properly aligned with the bore axis. If you can center your group on the bull, then you are pretty close to aligned and when you put the rear sight back on the rifle you should be...
by Jack Leslie
Wed Oct 26, 2005 3:55 pm
Forum: Olympic Rifle - Air and Smallbore
Topic: Cheek piece adjustment
Replies: 12
Views: 5706

You basically use your head/eye as the rear sight and adjust the cheek piece the same as you would your rear sight: if your group is low and to the left, you would move your cheekpiece up and right. Move the cheekpiece in the direction you want to move the group on the paper. When the group is cente...
by Jack Leslie
Fri Jun 10, 2005 8:14 am
Forum: Olympic Rifle - Air and Smallbore
Topic: pro & cons of newer type alum. stocks over wood.
Replies: 13
Views: 4320

Funny, I was told that repeatability is a problem with these small torque wrenches and that once you find your rifle's "sweet spot" you should never touch the adjustment!?!

Jack
by Jack Leslie
Thu Jun 09, 2005 11:25 am
Forum: Olympic Rifle - Air and Smallbore
Topic: Unertl Scope Help Needed
Replies: 0
Views: 720

Unertl Scope Help Needed

My local club is going to have a 200yd prone match in August and I thought that this would be a good time to use the Unertl scope that I bought a dozen years ago and never shoot. Last evening I was at the range looking for my 200yd zero and could not get anything resembling a group. With my iron sig...