Spent time at the range this weekend measuring the reticle in the 2.5x20 scope and breaking-in/sighting-in the new 16-inch SS 410 barrel.
To measure the reticle I set this up at 286.5 feet, which is the distance at which one MOA equals exactly one inch;
I clipped two pieces of paper on the 6-foot folding rule to make the measurement easier to see. After some experimentation, the right marker ended up at 63 inches to position them perfectly between the two heavy duplex posts. So the distance between those posts is 63 MOA, which I round up to 64 to make the math easier.
The pieces of paper along the top were used to measure the thickness of the narrow reticle. It looks to be just about 1.5 MOA for the thinner sections, which is actually quite useful (more on that in a bit).
With the Speer 75 grain Gold Dot load, the final holdovers are as follows;
- 0 - 230 yards - POI will remain +/- 2-inches verically to POA.
- 300 yards - hold over nine inches, based on size of target.
For distances beyond 300 yards I divide the space between the center cross hair and tip of the bottom post in a way that I can judge with reasonable precision;
- 1/2 way down to the tip of the post is 16 MOA, or about 600 yards, which is about as far as I'm going to reach out with this rifle.
- 1/4 way down is 8 MOA, or about 430 yards
- 1/3 way down is 10 MOA, or about 475 yards
So while this is obviously not as precise as a true ranging reticle, knowing these holdovers is useful for the longer shots.
The BCM SS 410 Barrel
The first day at the range was windy, and much of my time was spent measuring the reticle and doing some breaking-in of the barrel, which included cleaning with patches of Hoppe's #9. It started off looking really good, but the groups kept opening up as the morning went on. By the time I had to leave the range due to a club activity, I was not impressed with the new barrel - though it showed flashes of brilliance. The best 5-shot group of day one was just about one MOA, and amazingly it was made with XM193 ball ammo. My go-to load, the Speer LE 75 grain Gold Dot load, did not do well at all. By the time I had to pack it up, I was wondering if the barrel was even worth the money and time i invested in it.
After a thorough cleaning of the barrel (which it turns out it really needed) I returned to the range this morning with just the Gold Dot load - it was either going to get me at least 1.5 MOA over a couple of 5-shot groups or I was going reinstall the old barrel. I fired a total of 10 rounds over two 5-shot groups. Group one measured 1.19 MOA, which was quite acceptable. I made my final adjustments to the scope and the second group measured 1.43 MOA, which one shot I called as high. Over both groups, four shots went into .77 MOA. The barrel will remain installed on my rifle. :-)
A key takeaway from all of this is that while a 2.5X is entirely adequate for hitting IDPA size targets out to WAY beyond "self defense" distance, it's NOT what you want to use to test the precision capability of a barrel. I suspect my precision-testing results would have been better with a higher magnification scope.
Now about that 1.5 MOA cross hair thickness - it is convenient visual indicator of my rifle's precision capability with the Gold Dot load when placed over the target. If the cross hair obscures what I want to hit, it's unlikely that I will be able to hit it with any degree of confidence.
My adventures with a Fudd scope on a SD carbine will continue.
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Originally Posted by TWR
