Took my new rifle out again last weekend of July and stretched my sight-in to the 200 and 300 yard mark. I made the full transition over to Hornady 143 grain ELD-X bullets which will be hunting round for deer-sized game. If I ever take the Creedmoor out for elk or bear, I will probably re-zero with a bonded bullet for better penetration and controlled expansion. Anyways, I checked the zero again at 100 yards and still performing at around 0.5 MOA and cutting same bullet holes every other round. At this stage, the gun is shooting BETTER than I had hoped. After checking the zero, I fired 3 rounds through my cousin’s chronograph which clocked an average of 2,775 FPS. A full 75 feet-per-second faster than the box advertises…I guess that’s the 26” barrel paying off.
Anyways, punched all that info into a bullet drop app – I’m using Strelok which works well on Androids – and walked out to 200, then 300 yards still shooting off a bench. My groups expanded a little, a little closer to MOA at 200 and 300 yards but still grouping great. Unfortunately, my bullets were consistently falling further and further below the bullseye as I pushed the distance out past zero. I needed another click at 200 yards and 2+ extra clicks to make dead nuts at 300 yards. (If you’re a gun nerd and are curious about such things – unlike myself – scope is in MRADs). A bit more discouraging is that the discrepancy is going to exaggerate the further out I go. So much so that by the time I push the gun to 500 yards, my actual bullet drop will be approximately 10” lower than what my bullet drop app is kicking out based on my input data.
Put this chart together to show what Strelok says should be happening with drop trajectory according to my input, then played with numbers to adjust FPS all the way down to 2575. That muzzle velocity, 2575 FPS, is what I had to enter as input data (which is 200 FPS slower than my rifle’s actual performance) in order to best replicate the drop I was observing in the field from a 100 yard zero to 300 yards. I hated to do that but wasn’t sure what else to do.
Now, I have reached out to a couple forums to seek out assistance and guidance for remedying my conundrum. The feedback I’ve received so far seems to indicate that this approach should solve the problem, but I’m not confident enough to take that system in the field without a little more ground truthing. I suppose the old fashioned method of moving back in 50 yard increments will be sufficient to learn my load’s clicks at each range. That will be pretty time consuming but that is what I need to do in order to have confidence at longer ranges out past the 300 yard marker. Ideally, I can do the range work necessary to make myself proficient (sub-MOA) out to 600-650 yards. If I can do that on the range, I feel confident that I could be extremely effective in most hunting situations to somewhere between 400 and 500 yards.