Monday, April 22, 2013

Final Chapter on The Eliseo-W52

The rigid frame tests did not represent the innate accuracy of the barrel-receiver assembly. Some compliance is needed as shown elsewher and as mentioned here. The vibrational characteristics of the assembly are extremely complex and all most of us can do is conjecture. Real analysis is left to large budget organizations; however, my original assumption can neither be verified or debunked from the data presented. I have bungled into a shooter. Since the original testing post some months ago. Today after much consternation I am relieved to publish the rifle receiver-barrel is capable of more than 1/2 minute of angle at 100 yards; however, this statement is qualitative vs. quantitative. I fired 50 rounds today, which is good for me, temperature 70^F, wind varies at 7-10 mph, relative humidity 45%, sunny with few clouds. All at 100 yds. The time was from 1:30 to 2:30 PM. Now the wind is calm and I should be shooting. Oh well.
Here is my last target.


Relatively typical of the last 30 rounds, after I got settled down. Wolf ET and a few UM22 off sand bags and prone. 10 rounds. The 10 at 11:00 was yours truly. I was holding off to make wind corrections and holding low to compensate for excessive slope in the scope ramp. 0.015" lower  would make my job easier. The were called shots. Specific conditions of compensation will not add to the narrative, so I will avoid that issue in the quest of conciseness. A good shooter could get less than 1/2" at 100. The distinct 9:00 and 3:00 are just that. The vertical dispersion is a result of guessing at my "low" hold and sometimes not getting it corect.

 The original scope ramp was too low and the addition of the medium to high Burris rings did not solve the problem.


Now ammunition is not easy to find and I wasted half a brick before I realized I was "cheeking" the stock adjustment screw  was full down. Also as I wished to change scopes, refinements in the windage and elevation adjustment was necessary, so I just constructed a new ramp with those features. Impossible to see in the photo are capstan nuts that move a sliding bar at the rear ring mount. The construction was not easy since there seems to be holes everywher to avoid. Loosen the Burris rings and adjust the capstan appropriately. Shims and slope accomodate the vertical about 0.020" between front and back rings. Bore sighting took less than 10 min to acheive and the result was within 4" of center. That is when I discovered I did not have enough "down" movement. I am not happy with the Burris scope. The clicks are too coarse and the resolution inadequate for an old man. Futhermore, the higher powers are worthless. The old 10X Weaver as seen in other photos lacked resolution also. Thus replacement did not solve the problem.  What I need is a good fixed power 12X with 1" tubes.  Maybe it is just my "tired" eyes.

Were I to contemplate this project again the stock would consist of Eliseo front and back; however the stock-receiver portion would be a U shape. Also I have a Remington action that can be used and that will be my next endeavor.

No comments:

Post a Comment