It's important to note that as we get several rounds through the rifle, 100 rounds, 500 rounds, and sometimes 1,000 rounds, that we may exhibit a change in velocity. By keeping good records as to initial load development and accuracy testing should we see a decline in the accuracy from our rifle, grab the chronograph and shoot the ammunition over the chronograph. You may see a velocity change that has now taken us out of the accurate node. If it's a lower velocity simply add a little more powder to the load, run back to the range and try and replicate the initial load velocity that produced those bug whole groups early on. Temperature conditions can also change. In the benchrest circles when these individuals travel around from state to state competing in who can shoot the smallest groups they're gonna get to the range days in advance and fine-tune and develop their load based upon those atmospheric conditions at that given location. He can become that sensitive when you're shooting for gold and group size is measured in thousandths of an inch.
Another thing to keep in mind is when you're dealing with different powders and stuff you will get a velocity change that will affect the long range performance of the gun. If we've done careful load development and we've established an average velocity as an example now of 3,000 feet a second, but yet we go to Montana in the winter time and it zero out and that velocity drops from 3,000 to 2,950, that 50 foot a second change in muzzle velocity will have an effect on our down range trajectory curve. The time a flight of the bullet to get from the shooter to the target at long range has changed due to the 50 foot a second decrease in velocity and that's going to cause the bullet to imprint low at extreme ranges. From 100 to 500 yards, a 50 foot change up or down in velocity is not going to allow you to miss the deer, elk, or antelope.
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